Author: slebresne
Date: Tue Dec 22 10:57:15 2015
New Revision: 1721342
URL: http://svn.apache.org/viewvc?rev=1721342&view=rev
Log:
Update CQL doc dor CASSANDRA-10701
Added:
cassandra/site/publish/doc/cql3/CQL-3.0.html
Modified:
cassandra/site/publish/doc/cql3/CQL-2.1.html
cassandra/site/publish/doc/cql3/CQL-2.2.html
Modified: cassandra/site/publish/doc/cql3/CQL-2.1.html
URL:
http://svn.apache.org/viewvc/cassandra/site/publish/doc/cql3/CQL-2.1.html?rev=1721342&r1=1721341&r2=1721342&view=diff
==============================================================================
--- cassandra/site/publish/doc/cql3/CQL-2.1.html (original)
+++ cassandra/site/publish/doc/cql3/CQL-2.1.html Tue Dec 22 10:57:15 2015
@@ -1,4 +1,4 @@
-<?xml version='1.0' encoding='utf-8' ?><!DOCTYPE html PUBLIC "-//W3C//DTD
XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd";><html
xmlns="http://www.w3.org/1999/xhtml";><head><meta http-equiv="Content-Type"
content="text/html; charset=utf-8"/><title>CQL</title></head><body><p><link
rel="StyleSheet" href="CQL.css" type="text/css" media="screen"></p><h1
id="CassandraQueryLanguageCQLv3.2.0">Cassandra Query Language (CQL)
v3.2.0</h1><span id="tableOfContents"><ol style="list-style: none;"><li><a
href="CQL.html#CassandraQueryLanguageCQLv3.2.0">Cassandra Query Language (CQL)
v3.2.0</a><ol style="list-style: none;"><li><a href="CQL.html#CQLSyntax">CQL
Syntax</a><ol style="list-style: none;"><li><a
href="CQL.html#Preamble">Preamble</a></li><li><a
href="CQL.html#Conventions">Conventions</a></li><li><a
href="CQL.html#identifiers">Identifiers and keywords</a></li><li><a
href="CQL.html#constants">Constants</a></li><li><a
href="CQL.html#Comments">Comments</a></l
i><li><a href="CQL.html#statements">Statements</a></li><li><a
href="CQL.html#preparedStatement">Prepared Statement</a></li></ol></li><li><a
href="CQL.html#dataDefinition">Data Definition</a><ol style="list-style:
none;"><li><a href="CQL.html#createKeyspaceStmt">CREATE KEYSPACE</a></li><li><a
href="CQL.html#useStmt">USE</a></li><li><a
href="CQL.html#alterKeyspaceStmt">ALTER KEYSPACE</a></li><li><a
href="CQL.html#dropKeyspaceStmt">DROP KEYSPACE</a></li><li><a
href="CQL.html#createTableStmt">CREATE TABLE</a></li><li><a
href="CQL.html#alterTableStmt">ALTER TABLE</a></li><li><a
href="CQL.html#dropTableStmt">DROP TABLE</a></li><li><a
href="CQL.html#truncateStmt">TRUNCATE</a></li><li><a
href="CQL.html#createIndexStmt">CREATE INDEX</a></li><li><a
href="CQL.html#dropIndexStmt">DROP INDEX</a></li><li><a
href="CQL.html#createTypeStmt">CREATE TYPE</a></li><li><a
href="CQL.html#alterTypeStmt">ALTER TYPE</a></li><li><a
href="CQL.html#dropTypeStmt">DROP TYPE</a></li><li><a href="CQL.html#createTri
ggerStmt">CREATE TRIGGER</a></li><li><a href="CQL.html#dropTriggerStmt">DROP
TRIGGER</a></li></ol></li><li><a href="CQL.html#dataManipulation">Data
Manipulation</a><ol style="list-style: none;"><li><a
href="CQL.html#insertStmt">INSERT</a></li><li><a
href="CQL.html#updateStmt">UPDATE</a></li><li><a
href="CQL.html#deleteStmt">DELETE</a></li><li><a
href="CQL.html#batchStmt">BATCH</a></li></ol></li><li><a
href="CQL.html#queries">Queries</a><ol style="list-style: none;"><li><a
href="CQL.html#selectStmt">SELECT</a></li></ol></li><li><a
href="CQL.html#databaseUsers">Database Users</a><ol style="list-style:
none;"><li><a href="CQL.html#createUserStmt">CREATE USER </a></li><li><a
href="CQL.html#alterUserStmt">ALTER USER </a></li><li><a
href="CQL.html#dropUserStmt">DROP USER </a></li><li><a
href="CQL.html#listUsersStmt">LIST USERS</a></li></ol></li><li><a
href="CQL.html#dataControl">Data Control</a><ol style="list-style:
none;"><li><a href="CQL.html#permissions">Permissions </a></li><li><a hr
ef="CQL.html#grantPermissionsStmt">GRANT PERMISSION</a></li><li><a
href="CQL.html#revokePermissionsStmt">REVOKE
PERMISSION</a></li></ol></li><li><a href="CQL.html#types">Data Types</a><ol
style="list-style: none;"><li><a href="CQL.html#usingdates">Working with
dates</a></li><li><a href="CQL.html#counters">Counters</a></li><li><a
href="CQL.html#collections">Working with collections</a></li></ol></li><li><a
href="CQL.html#functions">Functions</a><ol style="list-style: none;"><li><a
href="CQL.html#tokenFun">Token</a></li><li><a
href="CQL.html#uuidFun">Uuid</a></li><li><a
href="CQL.html#timeuuidFun">Timeuuid functions</a></li><li><a
href="CQL.html#blobFun">Blob conversion functions</a></li></ol></li><li><a
href="CQL.html#appendixA">Appendix A: CQL Keywords</a></li><li><a
href="CQL.html#appendixB">Appendix B: CQL Reserved Types</a></li><li><a
href="CQL.html#changes">Changes</a><ol style="list-style: none;"><li><a
href="CQL.html#a3.2.0">3.2.0</a></li><li><a href="CQL.html#a3.1.7">3.1.7</a
></li><li><a href="CQL.html#a3.1.6">3.1.6</a></li><li><a
>href="CQL.html#a3.1.5">3.1.5</a></li><li><a
>href="CQL.html#a3.1.4">3.1.4</a></li><li><a
>href="CQL.html#a3.1.3">3.1.3</a></li><li><a
>href="CQL.html#a3.1.2">3.1.2</a></li><li><a
>href="CQL.html#a3.1.1">3.1.1</a></li><li><a
>href="CQL.html#a3.1.0">3.1.0</a></li><li><a
>href="CQL.html#a3.0.5">3.0.5</a></li><li><a
>href="CQL.html#a3.0.4">3.0.4</a></li><li><a
>href="CQL.html#a3.0.3">3.0.3</a></li><li><a
>href="CQL.html#a3.0.2">3.0.2</a></li><li><a
>href="CQL.html#a3.0.1">3.0.1</a></li></ol></li><li><a
>href="CQL.html#Versioning">Versioning</a></li></ol></li></ol></span><h2
>id="CQLSyntax">CQL Syntax</h2><h3 id="Preamble">Preamble</h3><p>This document
>describes the Cassandra Query Language (CQL) version 3. CQL v3 is not
>backward compatible with CQL v2 and differs from it in numerous ways. Note
>that this document describes the last version of the languages. However, the
><a href="#changes">changes</a> section provides the diff between the diffe
rent versions of CQL v3.</p><p>CQL v3 offers a model very close to SQL in the
sense that data is put in <em>tables</em> containing <em>rows</em> of
<em>columns</em>. For that reason, when used in this document, these terms
(tables, rows and columns) have the same definition than they have in SQL. But
please note that as such, they do <strong>not</strong> refer to the concept of
rows and columns found in the internal implementation of Cassandra and in the
thrift and CQL v2 API.</p><h3 id="Conventions">Conventions</h3><p>To aid in
specifying the CQL syntax, we will use the following conventions in this
document:</p><ul><li>Language rules will be given in a <a
href="http://en.wikipedia.org/wiki/Backus%E2%80%93Naur_Form";>BNF</a> -like
notation:</li></ul><pre class="syntax"><pre><start> ::= TERMINAL
<non-terminal1> <non-terminal1>
+<?xml version='1.0' encoding='utf-8' ?><!DOCTYPE html PUBLIC "-//W3C//DTD
XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd";><html
xmlns="http://www.w3.org/1999/xhtml";><head><meta http-equiv="Content-Type"
content="text/html; charset=utf-8"/><title>CQL</title></head><body><p><link
rel="StyleSheet" href="CQL.css" type="text/css" media="screen"></p><h1
id="CassandraQueryLanguageCQLv3.2.1">Cassandra Query Language (CQL)
v3.2.1</h1><span id="tableOfContents"><ol style="list-style: none;"><li><a
href="CQL.html#CassandraQueryLanguageCQLv3.2.1">Cassandra Query Language (CQL)
v3.2.1</a><ol style="list-style: none;"><li><a href="CQL.html#CQLSyntax">CQL
Syntax</a><ol style="list-style: none;"><li><a
href="CQL.html#Preamble">Preamble</a></li><li><a
href="CQL.html#Conventions">Conventions</a></li><li><a
href="CQL.html#identifiers">Identifiers and keywords</a></li><li><a
href="CQL.html#constants">Constants</a></li><li><a
href="CQL.html#Comments">Comments</a></l
i><li><a href="CQL.html#statements">Statements</a></li><li><a
href="CQL.html#preparedStatement">Prepared Statement</a></li></ol></li><li><a
href="CQL.html#dataDefinition">Data Definition</a><ol style="list-style:
none;"><li><a href="CQL.html#createKeyspaceStmt">CREATE KEYSPACE</a></li><li><a
href="CQL.html#useStmt">USE</a></li><li><a
href="CQL.html#alterKeyspaceStmt">ALTER KEYSPACE</a></li><li><a
href="CQL.html#dropKeyspaceStmt">DROP KEYSPACE</a></li><li><a
href="CQL.html#createTableStmt">CREATE TABLE</a></li><li><a
href="CQL.html#alterTableStmt">ALTER TABLE</a></li><li><a
href="CQL.html#dropTableStmt">DROP TABLE</a></li><li><a
href="CQL.html#truncateStmt">TRUNCATE</a></li><li><a
href="CQL.html#createIndexStmt">CREATE INDEX</a></li><li><a
href="CQL.html#dropIndexStmt">DROP INDEX</a></li><li><a
href="CQL.html#createTypeStmt">CREATE TYPE</a></li><li><a
href="CQL.html#alterTypeStmt">ALTER TYPE</a></li><li><a
href="CQL.html#dropTypeStmt">DROP TYPE</a></li><li><a href="CQL.html#createTri
ggerStmt">CREATE TRIGGER</a></li><li><a href="CQL.html#dropTriggerStmt">DROP
TRIGGER</a></li></ol></li><li><a href="CQL.html#dataManipulation">Data
Manipulation</a><ol style="list-style: none;"><li><a
href="CQL.html#insertStmt">INSERT</a></li><li><a
href="CQL.html#updateStmt">UPDATE</a></li><li><a
href="CQL.html#deleteStmt">DELETE</a></li><li><a
href="CQL.html#batchStmt">BATCH</a></li></ol></li><li><a
href="CQL.html#queries">Queries</a><ol style="list-style: none;"><li><a
href="CQL.html#selectStmt">SELECT</a></li></ol></li><li><a
href="CQL.html#databaseUsers">Database Users</a><ol style="list-style:
none;"><li><a href="CQL.html#createUserStmt">CREATE USER </a></li><li><a
href="CQL.html#alterUserStmt">ALTER USER </a></li><li><a
href="CQL.html#dropUserStmt">DROP USER </a></li><li><a
href="CQL.html#listUsersStmt">LIST USERS</a></li></ol></li><li><a
href="CQL.html#dataControl">Data Control</a><ol style="list-style:
none;"><li><a href="CQL.html#permissions">Permissions </a></li><li><a hr
ef="CQL.html#grantPermissionsStmt">GRANT PERMISSION</a></li><li><a
href="CQL.html#revokePermissionsStmt">REVOKE
PERMISSION</a></li></ol></li><li><a href="CQL.html#types">Data Types</a><ol
style="list-style: none;"><li><a href="CQL.html#usingdates">Working with
dates</a></li><li><a href="CQL.html#counters">Counters</a></li><li><a
href="CQL.html#collections">Working with collections</a></li></ol></li><li><a
href="CQL.html#functions">Functions</a><ol style="list-style: none;"><li><a
href="CQL.html#tokenFun">Token</a></li><li><a
href="CQL.html#uuidFun">Uuid</a></li><li><a
href="CQL.html#timeuuidFun">Timeuuid functions</a></li><li><a
href="CQL.html#blobFun">Blob conversion functions</a></li></ol></li><li><a
href="CQL.html#appendixA">Appendix A: CQL Keywords</a></li><li><a
href="CQL.html#appendixB">Appendix B: CQL Reserved Types</a></li><li><a
href="CQL.html#changes">Changes</a><ol style="list-style: none;"><li><a
href="CQL.html#a3.2.1">3.2.1</a></li><li><a href="CQL.html#a3.2.0">3.2.0</a
></li><li><a href="CQL.html#a3.1.7">3.1.7</a></li><li><a
>href="CQL.html#a3.1.6">3.1.6</a></li><li><a
>href="CQL.html#a3.1.5">3.1.5</a></li><li><a
>href="CQL.html#a3.1.4">3.1.4</a></li><li><a
>href="CQL.html#a3.1.3">3.1.3</a></li><li><a
>href="CQL.html#a3.1.2">3.1.2</a></li><li><a
>href="CQL.html#a3.1.1">3.1.1</a></li><li><a
>href="CQL.html#a3.1.0">3.1.0</a></li><li><a
>href="CQL.html#a3.0.5">3.0.5</a></li><li><a
>href="CQL.html#a3.0.4">3.0.4</a></li><li><a
>href="CQL.html#a3.0.3">3.0.3</a></li><li><a
>href="CQL.html#a3.0.2">3.0.2</a></li><li><a
>href="CQL.html#a3.0.1">3.0.1</a></li></ol></li><li><a
>href="CQL.html#Versioning">Versioning</a></li></ol></li></ol></span><h2
>id="CQLSyntax">CQL Syntax</h2><h3 id="Preamble">Preamble</h3><p>This document
>describes the Cassandra Query Language (CQL) version 3. CQL v3 is not
>backward compatible with CQL v2 and differs from it in numerous ways. Note
>that this document describes the last version of the languages. However, the
><a href="#changes">changes</a>
section provides the diff between the different versions of CQL v3.</p><p>CQL
v3 offers a model very close to SQL in the sense that data is put in
<em>tables</em> containing <em>rows</em> of <em>columns</em>. For that reason,
when used in this document, these terms (tables, rows and columns) have the
same definition than they have in SQL. But please note that as such, they do
<strong>not</strong> refer to the concept of rows and columns found in the
internal implementation of Cassandra and in the thrift and CQL v2 API.</p><h3
id="Conventions">Conventions</h3><p>To aid in specifying the CQL syntax, we
will use the following conventions in this document:</p><ul><li>Language rules
will be given in a <a
href="http://en.wikipedia.org/wiki/Backus%E2%80%93Naur_Form";>BNF</a> -like
notation:</li></ul><pre class="syntax"><pre><start> ::= TERMINAL
<non-terminal1> <non-terminal1>
</pre></pre><ul><li>Nonterminal symbols will have <code><angle
brackets></code>.</li><li>As additional shortcut notations to BNF, we’ll
use traditional regular expression’s symbols (<code>?</code>,
<code>+</code> and <code>*</code>) to signify that a given symbol is optional
and/or can be repeated. We’ll also allow parentheses to group symbols and
the <code>[<characters>]</code> notation to represent any one of
<code><characters></code>.</li><li>The grammar is provided for documentation
purposes and leave some minor details out. For instance, the last column
definition in a <code>CREATE TABLE</code> statement is optional but supported
if present even though the provided grammar in this document suggest it is not
supported. </li><li>Sample code will be provided in a code block:</li></ul><pre
class="sample"><pre>SELECT sample_usage FROM cql;
</pre></pre><ul><li>References to keywords or pieces of CQL code in running
text will be shown in a <code>fixed-width font</code>.</li></ul><h3
id="identifiers">Identifiers and keywords</h3><p>The CQL language uses
<em>identifiers</em> (or <em>names</em>) to identify tables, columns and other
objects. An identifier is a token matching the regular expression
<code>[a-zA-Z]</code><code>[a-zA-Z0-9_]</code><code>*</code>.</p><p>A number of
such identifiers, like <code>SELECT</code> or <code>WITH</code>, are
<em>keywords</em>. They have a fixed meaning for the language and most are
reserved. The list of those keywords can be found in <a
href="#appendixA">Appendix A</a>.</p><p>Identifiers and (unquoted) keywords are
case insensitive. Thus <code>SELECT</code> is the same than <code>select</code>
or <code>sElEcT</code>, and <code>myId</code> is the same than
<code>myid</code> or <code>MYID</code> for instance. A convention often used
(in particular by the samples of this documentation) is t
o use upper case for keywords and lower case for other
identifiers.</p><p>There is a second kind of identifiers called <em>quoted
identifiers</em> defined by enclosing an arbitrary sequence of characters in
double-quotes(<code>"</code>). Quoted identifiers are never keywords. Thus
<code>"select"</code> is not a reserved keyword and can be used to refer to a
column, while <code>select</code> would raise a parse error. Also, contrarily
to unquoted identifiers and keywords, quoted identifiers are case sensitive
(<code>"My Quoted Id"</code> is <em>different</em> from <code>"my quoted
id"</code>). A fully lowercase quoted identifier that matches
<code>[a-zA-Z]</code><code>[a-zA-Z0-9_]</code><code>*</code> is equivalent to
the unquoted identifier obtained by removing the double-quote (so
<code>"myid"</code> is equivalent to <code>myid</code> and to <code>myId</code>
but different from <code>"myId"</code>). Inside a quoted identifier, the
double-quote character can be repeated to escape it
, so <code>"foo "" bar"</code> is a valid identifier.</p><h3
id="constants">Constants</h3><p>CQL defines the following kind of
<em>constants</em>: strings, integers, floats, booleans, uuids and
blobs:</p><ul><li>A string constant is an arbitrary sequence of characters
characters enclosed by single-quote(<code>'</code>). One can include a
single-quote in a string by repeating it, e.g. <code>'It''s raining
today'</code>. Those are not to be confused with quoted identifiers that use
double-quotes.</li><li>An integer constant is defined by
<code>'-'?[0-9]+</code>.</li><li>A float constant is defined by
<code>'-'?[0-9]+('.'[0-9]*)?([eE][+-]?[0-9+])?</code>. On top of that,
<code>NaN</code> and <code>Infinity</code> are also float constants.</li><li>A
boolean constant is either <code>true</code> or <code>false</code> up to
case-insensitivity (i.e. <code>True</code> is a valid boolean
constant).</li><li>A <a
href="http://en.wikipedia.org/wiki/Universally_unique_identifier";>UUID</a>
constan
t is defined by <code>hex{8}-hex{4}-hex{4}-hex{4}-hex{12}</code> where
<code>hex</code> is an hexadecimal character, e.g. <code>[0-9a-fA-F]</code> and
<code>{4}</code> is the number of such characters.</li><li>A blob constant is
an hexadecimal number defined by <code>0[xX](hex)+</code> where
<code>hex</code> is an hexadecimal character, e.g.
<code>[0-9a-fA-F]</code>.</li></ul><p>For how these constants are typed, see
the <a href="#types">data types section</a>.</p><h3
id="Comments">Comments</h3><p>A comment in CQL is a line beginning by either
double dashes (<code>--</code>) or double slash
(<code>//</code>).</p><p>Multi-line comments are also supported through
enclosure within <code>/*</code> and <code>*/</code> (but nesting is not
supported).</p><pre class="sample"><pre>-- This is a comment
// This is a comment too
@@ -101,7 +101,7 @@ CREATE TABLE timeline (
INSERT INTO test(pk, t, v, s) VALUES (0, 0, 'val0', 'static0');
INSERT INTO test(pk, t, v, s) VALUES (0, 1, 'val1', 'static1');
SELECT * FROM test WHERE pk=0 AND t=0;
-</pre></pre><p>the last query will return <code>'static1'</code> as value for
<code>s</code>, since <code>s</code> is static and thus the 2nd insertion
modified this “shared” value. Note however that static columns are
only static within a given partition, and if in the example above both rows
where from different partitions (i.e. if they had different value for
<code>pk</code>), then the 2nd insertion would not have modified the value of
<code>s</code> for the first row.</p><p>A few restrictions applies to when
static columns are allowed:</p><ul><li>tables with the <code>COMPACT
STORAGE</code> option (see below) cannot have them</li><li>a table without
clustering columns cannot have static columns (in a table without clustering
columns, every partition has only one row, and so every column is inherently
static).</li><li>only non <code>PRIMARY KEY</code> columns can be
static</li></ul><h4 id="createTableOptions"><code><option></code></h4><p>The
<code>CREATE TABLE</cod
e> statement supports a number of options that controls the configuration of a
new table. These options can be specified after the <code>WITH</code>
keyword.</p><p>The first of these option is <code>COMPACT STORAGE</code>. This
option is mainly targeted towards backward compatibility for definitions
created before CQL3 (see <a
href="http://www.datastax.com/dev/blog/thrift-to-cql3";>www.datastax.com/dev/blog/thrift-to-cql3</a>
for more details). The option also provides a slightly more compact layout of
data on disk but at the price of diminished flexibility and extensibility for
the table. Most notably, <code>COMPACT STORAGE</code> tables cannot have
collections nor static columns and a <code>COMPACT STORAGE</code> table with at
least one clustering column supports exactly one (as in not 0 nor more than 1)
column not part of the <code>PRIMARY KEY</code> definition (which imply in
particular that you cannot add nor remove columns after creation). For those
reasons, <code>COMPACT STO
RAGE</code> is not recommended outside of the backward compatibility reason
evoked above.</p><p>Another option is <code>CLUSTERING ORDER</code>. It allows
to define the ordering of rows on disk. It takes the list of the clustering
column names with, for each of them, the on-disk order (Ascending or
descending). Note that this option affects <a href="#selectOrderBy">what
<code>ORDER BY</code> are allowed during <code>SELECT</code></a>.</p><p>Table
creation supports the following other
<code><property></code>:</p><table><tr><th>option
</th><th>kind </th><th>default
</th><th>description</th></tr><tr><td><code>comment</code>
</td><td><em>simple</em> </td><td>none </td><td>A free-form,
human-readable comment.</td></tr><tr><td><code>read_repair_chance</code>
</td><td><em>simple</em> </td><td>0.1 </td><td>The probability with
which to query extra nodes (e.g. more nodes than required by the consistency
level) for the purpos
e of read repairs.</td></tr><tr><td><code>dclocal_read_repair_chance</code>
</td><td><em>simple</em> </td><td>0 </td><td>The probability with
which to query extra nodes (e.g. more nodes than required by the consistency
level) belonging to the same data center than the read coordinator for the
purpose of read repairs.</td></tr><tr><td><code>gc_grace_seconds</code>
</td><td><em>simple</em> </td><td>864000 </td><td>Time to wait before
garbage collecting tombstones (deletion
markers).</td></tr><tr><td><code>bloom_filter_fp_chance</code>
</td><td><em>simple</em> </td><td>0.00075 </td><td>The target probability
of false positive of the sstable bloom filters. Said bloom filters will be
sized to provide the provided probability (thus lowering this value impact the
size of bloom filters in-memory and
on-disk)</td></tr><tr><td><code>compaction</code>
</td><td><em>map</em> </td><td><em>see below</em> </td><td>The compaction
options to use, se
e below.</td></tr><tr><td><code>compression</code>
</td><td><em>map</em> </td><td><em>see below</em> </td><td>Compression
options, see below. </td></tr><tr><td><code>caching</code>
</td><td><em>simple</em> </td><td>keys_only </td><td>Whether to cache keys
(“key cache”) and/or rows (“row cache”) for this table.
Valid values are: <code>all</code>, <code>keys_only</code>,
<code>rows_only</code> and <code>none</code>.
</td></tr><tr><td><code>default_time_to_live</code>
</td><td><em>simple</em> </td><td>0 </td><td>The default expiration
time (“TTL”) in seconds for a table.</td></tr></table><h4
id="compactionOptions"><code>compaction</code> options</h4><p>The
<code>compaction</code> property must at least define the <code>'class'</code>
sub-option, that defines the compaction strategy class to use. The default
supported class are <code>'SizeTieredCompactionStrategy'</code> and
<code>'LeveledCompacti
onStrategy'</code>. Custom strategy can be provided by specifying the full
class name as a <a href="#constants">string constant</a>. The rest of the
sub-options depends on the chosen class. The sub-options supported by the
default classes are:</p><table><tr><th>option
</th><th>supported compaction strategy </th><th>default </th><th>description
</th></tr><tr><td><code>enabled</code>
</td><td><em>all</em> </td><td>true </td><td>A
boolean denoting whether compaction should be enabled or
not.</td></tr><tr><td><code>tombstone_threshold</code>
</td><td><em>all</em> </td><td>0.2 </td><td>A
ratio such that if a sstable has more than this ratio of gcable tombstones over
all contained columns, the sstable will be compacted (with no other sstables)
for the purpose of purging those tombstones.
</td></tr><tr><td><code>tombstone_compaction_interval</code>
</td><td><em>all</em>
</td><td>1 day </td><td>The minimum time to
wait after an sstable creation time before considering it for “tombstone
compaction”, where “tombstone compaction” is the compaction
triggered if the sstable has more gcable tombstones than
<code>tombstone_threshold</code>.
</td></tr><tr><td><code>unchecked_tombstone_compaction</code>
</td><td><em>all</em> </td><td>false
</td><td>Setting this to true enables more aggressive tombstone compactions
– single sstable tombstone compactions will run without checking how
likely it is that they will be successful.
</td></tr><tr><td><code>min_sstable_size</code>
</td><td>SizeTieredCompactionStrategy </td><td>50MB </td><td>The size
tiered strategy groups SSTables to compact in buckets. A bucket groups SSTables
that differs from less than 50% in size. However, for small sizes, this would
result in a bucketing that is too fine grained. <code
>min_sstable_size</code> defines a size threshold (in bytes) below which all
>SSTables belong to one unique
>bucket</td></tr><tr><td><code>min_threshold</code>
></td><td>SizeTieredCompactionStrategy </td><td>4 </td><td>Minimum
>number of SSTables needed to start a minor
>compaction.</td></tr><tr><td><code>max_threshold</code>
></td><td>SizeTieredCompactionStrategy </td><td>32 </td><td>Maximum
>number of SSTables processed by one minor
>compaction.</td></tr><tr><td><code>bucket_low</code>
></td><td>SizeTieredCompactionStrategy </td><td>0.5 </td><td>Size
>tiered consider sstables to be within the same bucket if their size is within
>[average_size * <code>bucket_low</code>, average_size *
><code>bucket_high</code> ] (i.e the default groups sstable whose sizes
>diverges by at most 50%)</td></tr><tr><td><code>bucket_high</code>
> </td><td>SizeTieredCompactionStrategy </td><td>1.5
></td><td>Siz
e tiered consider sstables to be within the same bucket if their size is
within [average_size * <code>bucket_low</code>, average_size *
<code>bucket_high</code> ] (i.e the default groups sstable whose sizes diverges
by at most 50%).</td></tr><tr><td><code>sstable_size_in_mb</code>
</td><td>LeveledCompactionStrategy </td><td>5MB </td><td>The target
size (in MB) for sstables in the leveled strategy. Note that while sstable
sizes should stay less or equal to <code>sstable_size_in_mb</code>, it is
possible to exceptionally have a larger sstable as during compaction, data for
a given partition key are never split into 2 sstables</td></tr></table><p>For
the <code>compression</code> property, the following default sub-options are
available:</p><table><tr><th>option </th><th>default
</th><th>description </th></tr><tr><td><code>sstable_compression</code>
</td><td>LZ4Compressor </td><td>The compression algorithm to use. Default
compressor are: LZ
4Compressor, SnappyCompressor and DeflateCompressor. Use an empty string
(<code>''</code>) to disable compression. Custom compressor can be provided by
specifying the full class name as a <a href="#constants">string
constant</a>.</td></tr><tr><td><code>chunk_length_kb</code> </td><td>64KB
</td><td>On disk SSTables are compressed by block (to allow random
reads). This defines the size (in KB) of said block. Bigger values may improve
the compression rate, but increases the minimum size of data to be read from
disk for a read </td></tr><tr><td><code>crc_check_chance</code> </td><td>1.0
</td><td>When compression is enabled, each compressed block
includes a checksum of that block for the purpose of detecting disk bitrot and
avoiding the propagation of corruption to other replica. This option defines
the probability with which those checksums are checked during read. By default
they are always checked. Set to 0 to disable checksum checking and to 0.5 for in
stance to check them every other read</td></tr></table><h4
id="Otherconsiderations">Other considerations:</h4><ul><li>When <a
href="#insertStmt/"updating":#updateStmt">inserting</a> a given row,
not all columns needs to be defined (except for those part of the key), and
missing columns occupy no space on disk. Furthermore, adding new columns (see
<a href=#alterStmt><tt>ALTER TABLE</tt></a>) is a constant time operation.
There is thus no need to try to anticipate future usage (or to cry when you
haven’t) when creating a table.</li></ul><h3 id="alterTableStmt">ALTER
TABLE</h3><p><i>Syntax:</i></p><pre class="syntax"><pre><alter-table-stmt>
::= ALTER (TABLE | COLUMNFAMILY) <tablename> <instruction>
+</pre></pre><p>the last query will return <code>'static1'</code> as value for
<code>s</code>, since <code>s</code> is static and thus the 2nd insertion
modified this “shared” value. Note however that static columns are
only static within a given partition, and if in the example above both rows
where from different partitions (i.e. if they had different value for
<code>pk</code>), then the 2nd insertion would not have modified the value of
<code>s</code> for the first row.</p><p>A few restrictions applies to when
static columns are allowed:</p><ul><li>tables with the <code>COMPACT
STORAGE</code> option (see below) cannot have them</li><li>a table without
clustering columns cannot have static columns (in a table without clustering
columns, every partition has only one row, and so every column is inherently
static).</li><li>only non <code>PRIMARY KEY</code> columns can be
static</li></ul><h4 id="createTableOptions"><code><option></code></h4><p>The
<code>CREATE TABLE</cod
e> statement supports a number of options that controls the configuration of a
new table. These options can be specified after the <code>WITH</code>
keyword.</p><p>The first of these option is <code>COMPACT STORAGE</code>. This
option is mainly targeted towards backward compatibility for definitions
created before CQL3 (see <a
href="http://www.datastax.com/dev/blog/thrift-to-cql3";>www.datastax.com/dev/blog/thrift-to-cql3</a>
for more details). The option also provides a slightly more compact layout of
data on disk but at the price of diminished flexibility and extensibility for
the table. Most notably, <code>COMPACT STORAGE</code> tables cannot have
collections nor static columns and a <code>COMPACT STORAGE</code> table with at
least one clustering column supports exactly one (as in not 0 nor more than 1)
column not part of the <code>PRIMARY KEY</code> definition (which imply in
particular that you cannot add nor remove columns after creation). For those
reasons, <code>COMPACT STO
RAGE</code> is not recommended outside of the backward compatibility reason
evoked above.</p><p>Another option is <code>CLUSTERING ORDER</code>. It allows
to define the ordering of rows on disk. It takes the list of the clustering
column names with, for each of them, the on-disk order (Ascending or
descending). Note that this option affects <a href="#selectOrderBy">what
<code>ORDER BY</code> are allowed during <code>SELECT</code></a>.</p><p>Table
creation supports the following other
<code><property></code>:</p><table><tr><th>option
</th><th>kind </th><th>default
</th><th>description</th></tr><tr><td><code>comment</code>
</td><td><em>simple</em> </td><td>none </td><td>A free-form,
human-readable comment.</td></tr><tr><td><code>read_repair_chance</code>
</td><td><em>simple</em> </td><td>0.1 </td><td>The probability with
which to query extra nodes (e.g. more nodes than required by the consistency
level) for the purpos
e of read repairs.</td></tr><tr><td><code>dclocal_read_repair_chance</code>
</td><td><em>simple</em> </td><td>0 </td><td>The probability with
which to query extra nodes (e.g. more nodes than required by the consistency
level) belonging to the same data center than the read coordinator for the
purpose of read repairs.</td></tr><tr><td><code>gc_grace_seconds</code>
</td><td><em>simple</em> </td><td>864000 </td><td>Time to wait before
garbage collecting tombstones (deletion
markers).</td></tr><tr><td><code>bloom_filter_fp_chance</code>
</td><td><em>simple</em> </td><td>0.00075 </td><td>The target probability
of false positive of the sstable bloom filters. Said bloom filters will be
sized to provide the provided probability (thus lowering this value impact the
size of bloom filters in-memory and
on-disk)</td></tr><tr><td><code>default_time_to_live</code>
</td><td><em>simple</em> </td><td>0 </td><td>The default expiration
time (“TTL&
#8221;) in seconds for a table.</td></tr><tr><td><code>compaction</code>
</td><td><em>map</em> </td><td><em>see below</em>
</td><td>Compaction options, see <a
href="#compactionOptions">below</a>.</td></tr><tr><td><code>compression</code>
</td><td><em>map</em> </td><td><em>see below</em>
</td><td>Compression options, see <a
href="#compressionOptions">below</a>.</td></tr><tr><td><code>caching</code>
</td><td><em>map</em> </td><td><em>see below</em>
</td><td>Caching options, see <a
href="#cachingOptions">below</a>.</td></tr></table><h4
id="compactionOptions">Compaction options</h4><p>The <code>compaction</code>
property must at least define the <code>'class'</code> sub-option, that defines
the compaction strategy class to use. The default supported class are
<code>'SizeTieredCompactionStrategy'</code>,
<code>'LeveledCompactionStrategy'</code> and
<code>'DateTieredCompactionStrategy'</code>. Custom strategy can be provided by
sp
ecifying the full class name as a <a href="#constants">string constant</a>.
The rest of the sub-options depends on the chosen class. The sub-options
supported by the default classes are:</p><table><tr><th>option
</th><th>supported compaction strategy </th><th>default
</th><th>description </th></tr><tr><td><code>enabled</code>
</td><td><em>all</em> </td><td>true
</td><td>A boolean denoting whether compaction should be enabled or
not.</td></tr><tr><td><code>tombstone_threshold</code>
</td><td><em>all</em> </td><td>0.2
</td><td>A ratio such that if a sstable has more than this ratio of gcable
tombstones over all contained columns, the sstable will be compacted (with no
other sstables) for the purpose of purging those tombstones.
</td></tr><tr><td><code>tombstone_compaction_interval</code>
</td><td><em>all</em> </td><td>1 day
</td><td>The minimum time to wait after an sstable creation time before
considering it for “tombstone compaction”, where “tombstone
compaction” is the compaction triggered if the sstable has more gcable
tombstones than <code>tombstone_threshold</code>.
</td></tr><tr><td><code>unchecked_tombstone_compaction</code>
</td><td><em>all</em> </td><td>false
</td><td>Setting this to true enables more aggressive tombstone compactions
– single sstable tombstone compactions will run without checking how
likely it is that they will be successful.
</td></tr><tr><td><code>min_sstable_size</code>
</td><td>SizeTieredCompactionStrategy </td><td>50MB </td><td>The
size tiered strategy groups SSTables to compact in buckets. A bucket groups
SSTables that differs from less than 50% in size. However, for small sizes,
this would result in a bucketing that is too fine grained.
<code>min_sstable_size</code> defines a siz
e threshold (in bytes) below which all SSTables belong to one unique
bucket</td></tr><tr><td><code>min_threshold</code>
</td><td>SizeTieredCompactionStrategy </td><td>4 </td><td>Minimum
number of SSTables needed to start a minor
compaction.</td></tr><tr><td><code>max_threshold</code>
</td><td>SizeTieredCompactionStrategy </td><td>32 </td><td>Maximum
number of SSTables processed by one minor
compaction.</td></tr><tr><td><code>bucket_low</code>
</td><td>SizeTieredCompactionStrategy </td><td>0.5 </td><td>Size
tiered consider sstables to be within the same bucket if their size is within
[average_size * <code>bucket_low</code>, average_size *
<code>bucket_high</code> ] (i.e the default groups sstable whose sizes diverges
by at most 50%)</td></tr><tr><td><code>bucket_high</code>
</td><td>SizeTieredCompactionStrategy </td><td>1.5 </td><td>Size
tiered consider sstables
to be within the same bucket if their size is within [average_size *
<code>bucket_low</code>, average_size * <code>bucket_high</code> ] (i.e the
default groups sstable whose sizes diverges by at most
50%).</td></tr><tr><td><code>sstable_size_in_mb</code>
</td><td>LeveledCompactionStrategy </td><td>5MB </td><td>The
target size (in MB) for sstables in the leveled strategy. Note that while
sstable sizes should stay less or equal to <code>sstable_size_in_mb</code>, it
is possible to exceptionally have a larger sstable as during compaction, data
for a given partition key are never split into 2
sstables</td></tr><tr><td><code>timestamp_resolution</code>
</td><td>DateTieredCompactionStrategy </td><td>MICROSECONDS </td><td>The
timestamp resolution used when inserting data, could be MILLISECONDS,
MICROSECONDS etc (should be understandable by Java
TimeUnit)</td></tr><tr><td><code>base_time_seconds</code>
</td><td>DateTieredCompactionStrate
gy </td><td>60 </td><td>The base size of the time windows.
</td></tr><tr><td><code>max_sstable_age_days</code>
</td><td>DateTieredCompactionStrategy </td><td>365
</td><td>SSTables only containing data that is older than this will never be
compacted. </td></tr></table><h4 id="compressionOptions">Compression
options</h4><p>For the <code>compression</code> property, the following
sub-options are available:</p><table><tr><th>option
</th><th>default </th><th>description
</th></tr><tr><td><code>sstable_compression</code> </td><td>LZ4Compressor
</td><td>The compression algorithm to use. Default compressor are:
LZ4Compressor, SnappyCompressor and DeflateCompressor. Use an empty string
(<code>''</code>) to disable compression. Custom compressor can be provided by
specifying the full class name as a <a href="#constants">string
constant</a>.</td></tr><tr><td><code>chunk_length_kb</code> </td><td>64KB
</td><td>On disk SST
ables are compressed by block (to allow random reads). This defines the size
(in KB) of said block. Bigger values may improve the compression rate, but
increases the minimum size of data to be read from disk for a read
</td></tr><tr><td><code>crc_check_chance</code> </td><td>1.0
</td><td>When compression is enabled, each compressed block includes a checksum
of that block for the purpose of detecting disk bitrot and avoiding the
propagation of corruption to other replica. This option defines the probability
with which those checksums are checked during read. By default they are always
checked. Set to 0 to disable checksum checking and to 0.5 for instance to check
them every other read</td></tr></table><h4 id="cachingOptions">Caching
options</h4><p>For the <code>caching</code> property, the following sub-options
are available:</p><table><tr><th>option </th><th>default
</th><th>description </th></tr><tr><td><code>keys</code>
</td><td>
ALL </td><td>Whether to cache keys (“key cache”) for this table.
Valid values are: <code>ALL</code> and
<code>NONE</code>.</td></tr><tr><td><code>rows_per_partition</code>
</td><td>NONE </td><td>The amount of rows to cache per partition (“row
cache”). If an integer <code>n</code> is specified, the first
<code>n</code> queried rows of a partition will be cached. Other possible
options are <code>ALL</code>, to cache all rows of a queried partition, or
<code>NONE</code> to disable row caching.</td></tr></table><h4
id="Otherconsiderations">Other considerations:</h4><ul><li>When <a
href="#insertStmt/"updating":#updateStmt">inserting</a> a given row,
not all columns needs to be defined (except for those part of the key), and
missing columns occupy no space on disk. Furthermore, adding new columns (see
<a href=#alterStmt><tt>ALTER TABLE</tt></a>) is a constant time operation.
There is thus no need to try to anticipate future usage (or to cry when
you haven’t) when creating a table.</li></ul><h3
id="alterTableStmt">ALTER TABLE</h3><p><i>Syntax:</i></p><pre
class="syntax"><pre><alter-table-stmt> ::= ALTER (TABLE | COLUMNFAMILY)
<tablename> <instruction>
<instruction> ::= ALTER <identifier> TYPE <type>
| ADD <identifier> <type>
@@ -118,7 +118,7 @@ WITH comment = 'A most excellent and use
AND read_repair_chance = 0.2;
</pre></pre><p><br/>The <code>ALTER</code> statement is used to manipulate
table definitions. It allows for adding new columns, dropping existing ones,
changing the type of existing columns, or updating the table options. As with
table creation, <code>ALTER COLUMNFAMILY</code> is allowed as an alias for
<code>ALTER TABLE</code>.</p><p>The <code><tablename></code> is the table
name optionally preceded by the keyspace name. The
<code><instruction></code> defines the alteration to
perform:</p><ul><li><code>ALTER</code>: Update the type of a given defined
column. Note that the type of the <a
href="#createTablepartitionClustering">clustering columns</a> cannot be
modified as it induces the on-disk ordering of rows. Columns on which a <a
href="#createIndexStmt">secondary index</a> is defined have the same
restriction. Other columns are free from those restrictions (no validation of
existing data is performed), but it is usually a bad idea to change the type to
a non-compatible one,
unless no data have been inserted for that column yet, as this could confuse
CQL drivers/tools.</li><li><code>ADD</code>: Adds a new column to the table.
The <code><identifier></code> for the new column must not conflict with an
existing column. Moreover, columns cannot be added to tables defined with the
<code>COMPACT STORAGE</code> option.</li><li><code>DROP</code>: Removes a
column from the table. Dropped columns will immediately become unavailable in
the queries and will not be included in compacted sstables in the future. If a
column is readded, queries won’t return values written before the column
was last dropped. It is assumed that timestamps represent actual time, so if
this is not your case, you should NOT readd previously dropped columns. Columns
can’t be dropped from tables defined with the <code>COMPACT
STORAGE</code> option.</li><li><code>WITH</code>: Allows to update the options
of the table. The <a href="#createTableOptions">supported <code><option
></code></a> (and syntax) are the same as for the <code>CREATE TABLE</code>
>statement except that <code>COMPACT STORAGE</code> is not supported. Note
>that setting any <code>compaction</code> sub-options has the effect of
>erasing all previous <code>compaction</code> options, so you need to
>re-specify all the sub-options if you want to keep them. The same note
>applies to the set of <code>compression</code> sub-options.</li></ul><h3
>id="dropTableStmt">DROP TABLE</h3><p><i>Syntax:</i></p><pre
>class="syntax"><pre><drop-table-stmt> ::= DROP TABLE ( IF EXISTS )?
><tablename>
</pre></pre><p><i>Sample:</i></p><pre class="sample"><pre>DROP TABLE
worldSeriesAttendees;
-</pre></pre><p>The <code>DROP TABLE</code> statement results in the immediate,
irreversible removal of a table, including all data contained in it. As for
table creation, <code>DROP COLUMNFAMILY</code> is allowed as an alias for
<code>DROP TABLE</code>.</p><p>If the table does not exist, the statement will
return an error, unless <code>IF EXISTS</code> is used in which case the
operation is a no-op.</p><h3
id="truncateStmt">TRUNCATE</h3><p><i>Syntax:</i></p><pre
class="syntax"><pre><truncate-stmt> ::= TRUNCATE <tablename>
+</pre></pre><p>The <code>DROP TABLE</code> statement results in the immediate,
irreversible removal of a table, including all data contained in it. As for
table creation, <code>DROP COLUMNFAMILY</code> is allowed as an alias for
<code>DROP TABLE</code>.</p><p>If the table does not exist, the statement will
return an error, unless <code>IF EXISTS</code> is used in which case the
operation is a no-op.</p><h3
id="truncateStmt">TRUNCATE</h3><p><i>Syntax:</i></p><pre
class="syntax"><pre><truncate-stmt> ::= TRUNCATE ( TABLE | COLUMNFAMILY )?
<tablename>
</pre></pre><p><i>Sample:</i></p><pre class="sample"><pre>TRUNCATE
superImportantData;
</pre></pre><p>The <code>TRUNCATE</code> statement permanently removes all
data from a table.</p><h3 id="createIndexStmt">CREATE
INDEX</h3><p><i>Syntax:</i></p><pre class="syntax"><pre><create-index-stmt>
::= CREATE ( CUSTOM )? INDEX ( IF NOT EXISTS )? ( <indexname> )?
ON <tablename> '(' <index-identifier> ')'
@@ -252,7 +252,7 @@ DELETE phone FROM Users WHERE userid IN
INSERT INTO users (userid, password) VALUES ('user4', 'ch@ngem3c');
DELETE name FROM users WHERE userid = 'user1';
APPLY BATCH;
-</pre></pre><p>The <code>BATCH</code> statement group multiple modification
statements (insertions/updates and deletions) into a single statement. It
serves several purposes:</p><ol><li>It saves network round-trips between the
client and the server (and sometimes between the server coordinator and the
replicas) when batching multiple updates.</li><li>All updates in a
<code>BATCH</code> belonging to a given partition key are performed in
isolation.</li><li>By default, all operations in the batch are performed
atomically. See the notes on <a
href="#unloggedBatch"><code>UNLOGGED</code></a> for more
details.</li></ol><p>Note that:</p><ul><li><code>BATCH</code> statements may
only contain <code>UPDATE</code>, <code>INSERT</code> and <code>DELETE</code>
statements.</li><li>Batches are <em>not</em> a full analogue for SQL
transactions.</li><li>If a timestamp is not specified for each operation, then
all operations will be applied with the same timestamp. Due to
Cassandra’s conflict
resolution procedure in the case of <a
href="http://wiki.apache.org/cassandra/FAQ#clocktie";>timestamp ties</a>,
operations may be applied in an order that is different from the order they are
listed in the <code>BATCH</code> statement. To force a particular operation
ordering, you must specify per-operation timestamps.</li></ul><h4
id="unloggedBatch"><code>UNLOGGED</code></h4><p>By default, Cassandra uses a
batch log to ensure all operations in a batch are applied atomically. (Note
that the operations are still only isolated within a single
partition.)</p><p>There is a performance penalty for batch atomicity when a
batch spans multiple partitions. If you do not want to incur this penalty, you
can tell Cassandra to skip the batchlog with the <code>UNLOGGED</code> option.
If the <code>UNLOGGED</code> option is used, operations are only atomic within
a single partition.</p><h4 id="counterBatch"><code>COUNTER</code></h4><p>Use
the <code>COUNTER</code> option for batched counter updates.
Unlike other updates in Cassandra, counter updates are not
idempotent.</p><h4
id="batchOptions"><code><option></code></h4><p><code>BATCH</code> supports
both the <code>TIMESTAMP</code> option, with similar semantic to the one
described in the <a href="#updateOptions"><code>UPDATE</code></a> statement
(the timestamp applies to all the statement inside the batch). However, if
used, <code>TIMESTAMP</code> <strong>must not</strong> be used in the
statements within the batch.</p><h2 id="queries">Queries</h2><h3
id="selectStmt">SELECT</h3><p><i>Syntax:</i></p><pre
class="syntax"><pre><select-stmt> ::= SELECT <select-clause>
+</pre></pre><p>The <code>BATCH</code> statement group multiple modification
statements (insertions/updates and deletions) into a single statement. It
serves several purposes:</p><ol><li>It saves network round-trips between the
client and the server (and sometimes between the server coordinator and the
replicas) when batching multiple updates.</li><li>All updates in a
<code>BATCH</code> belonging to a given partition key are performed in
isolation.</li><li>By default, all operations in the batch are performed as
<code>LOGGED</code>, to ensure all mutations eventually complete (or none
will). See the notes on <a href="#unloggedBatch"><code>UNLOGGED</code></a> for
more details.</li></ol><p>Note that:</p><ul><li><code>BATCH</code> statements
may only contain <code>UPDATE</code>, <code>INSERT</code> and
<code>DELETE</code> statements.</li><li>Batches are <em>not</em> a full
analogue for SQL transactions.</li><li>If a timestamp is not specified for each
operation, then all operations wil
l be applied with the same timestamp. Due to Cassandra’s conflict
resolution procedure in the case of <a
href="http://wiki.apache.org/cassandra/FAQ#clocktie";>timestamp ties</a>,
operations may be applied in an order that is different from the order they are
listed in the <code>BATCH</code> statement. To force a particular operation
ordering, you must specify per-operation timestamps.</li></ul><h4
id="unloggedBatch"><code>UNLOGGED</code></h4><p>By default, Cassandra uses a
batch log to ensure all operations in a batch eventually complete or none will
(note however that operations are only isolated within a single
partition).</p><p>There is a performance penalty for batch atomicity when a
batch spans multiple partitions. If you do not want to incur this penalty, you
can tell Cassandra to skip the batchlog with the <code>UNLOGGED</code> option.
If the <code>UNLOGGED</code> option is used, a failed batch might leave the
patch only partly applied.</p><h4 id="counterBatch"><code>COU
NTER</code></h4><p>Use the <code>COUNTER</code> option for batched counter
updates. Unlike other updates in Cassandra, counter updates are not
idempotent.</p><h4
id="batchOptions"><code><option></code></h4><p><code>BATCH</code> supports
both the <code>TIMESTAMP</code> option, with similar semantic to the one
described in the <a href="#updateOptions"><code>UPDATE</code></a> statement
(the timestamp applies to all the statement inside the batch). However, if
used, <code>TIMESTAMP</code> <strong>must not</strong> be used in the
statements within the batch.</p><h2 id="queries">Queries</h2><h3
id="selectStmt">SELECT</h3><p><i>Syntax:</i></p><pre
class="syntax"><pre><select-stmt> ::= SELECT <select-clause>
FROM <tablename>
( WHERE <where-clause> )?
( ORDER BY <order-by> )?
@@ -445,4 +445,4 @@ UPDATE plays SET scores = scores - [ 12,
)
</pre></pre><p>then the <code>token</code> function will take a single
argument of type <code>text</code> (in that case, the partition key is
<code>userid</code> (there is no clustering columns so the partition key is the
same than the primary key)), and the return type will be
<code>bigint</code>.</p><h3 id="uuidFun">Uuid</h3><p>The <code>uuid</code>
function takes no parameters and generates a random type 4 uuid suitable for
use in INSERT or SET statements.</p><h3 id="timeuuidFun">Timeuuid
functions</h3><h4 id="now"><code>now</code></h4><p>The <code>now</code>
function takes no arguments and generates a new unique timeuuid (at the time
where the statement using it is executed). Note that this method is useful for
insertion but is largely non-sensical in <code>WHERE</code> clauses. For
instance, a query of the form</p><pre class="sample"><pre>SELECT * FROM myTable
WHERE t = now()
</pre></pre><p>will never return any result by design, since the value
returned by <code>now()</code> is guaranteed to be unique.</p><h4
id="minTimeuuidandmaxTimeuuid"><code>minTimeuuid</code> and
<code>maxTimeuuid</code></h4><p>The <code>minTimeuuid</code> (resp.
<code>maxTimeuuid</code>) function takes a <code>timestamp</code> value
<code>t</code> (which can be <a href="#usingdates">either a timestamp or a date
string</a>) and return a <em>fake</em> <code>timeuuid</code> corresponding to
the <em>smallest</em> (resp. <em>biggest</em>) possible <code>timeuuid</code>
having for timestamp <code>t</code>. So for instance:</p> <pre
class="sample"><pre>SELECT * FROM myTable WHERE t > maxTimeuuid('2013-01-01
00:05+0000') AND t < minTimeuuid('2013-02-02 10:00+0000')
-</pre></pre> <p>will select all rows where the <code>timeuuid</code> column
<code>t</code> is strictly older than ‘2013-01-01 00:05+0000’ but
strictly younger than ‘2013-02-02 10:00+0000’. Please note that
<code>t >= maxTimeuuid('2013-01-01 00:05+0000')</code> would still <em>not</em>
select a <code>timeuuid</code> generated exactly at ‘2013-01-01
00:05+0000’ and is essentially equivalent to <code>t >
maxTimeuuid('2013-01-01 00:05+0000')</code>.</p><p><em>Warning</em>: We called
the values generated by <code>minTimeuuid</code> and <code>maxTimeuuid</code>
<em>fake</em> UUID because they do no respect the Time-Based UUID generation
process specified by the <a href="http://www.ietf.org/rfc/rfc4122.txt";>RFC
4122</a>. In particular, the value returned by these 2 methods will not be
unique. This means you should only use those methods for querying (as in the
example above). Inserting the result of those methods is almost certainly <em>a
bad idea</em>.
</p><h4 id="dateOfandunixTimestampOf"><code>dateOf</code> and
<code>unixTimestampOf</code></h4><p>The <code>dateOf</code> and
<code>unixTimestampOf</code> functions take a <code>timeuuid</code> argument
and extract the embedded timestamp. However, while the <code>dateof</code>
function return it with the <code>timestamp</code> type (that most client,
including cqlsh, interpret as a date), the <code>unixTimestampOf</code>
function returns it as a <code>bigint</code> raw value.</p><h3
id="blobFun">Blob conversion functions</h3><p>A number of functions are
provided to “convert” the native types into binary data
(<code>blob</code>). For every <code><native-type></code> <code>type</code>
supported by CQL3 (a notable exceptions is <code>blob</code>, for obvious
reasons), the function <code>typeAsBlob</code> takes a argument of type
<code>type</code> and return it as a <code>blob</code>. Conversely, the
function <code>blobAsType</code> takes a 64-bit <code>blob</code> argum
ent and convert it to a <code>bigint</code> value. And so for instance,
<code>bigintAsBlob(3)</code> is <code>0x0000000000000003</code> and
<code>blobAsBigint(0x0000000000000003)</code> is <code>3</code>.</p><h2
id="appendixA">Appendix A: CQL Keywords</h2><p>CQL distinguishes between
<em>reserved</em> and <em>non-reserved</em> keywords. Reserved keywords cannot
be used as identifier, they are truly reserved for the language (but one can
enclose a reserved keyword by double-quotes to use it as an identifier).
Non-reserved keywords however only have a specific meaning in certain context
but can used as identifer otherwise. The only <em>raison d'être</em> of these
non-reserved keywords is convenience: some keyword are non-reserved when it was
always easy for the parser to decide whether they were used as keywords or
not.</p><table><tr><th>Keyword </th><th>Reserved?
</th></tr><tr><td><code>ADD</code> </td><td>yes
</td></tr><tr><td><code>ALL</code> </td><td>no
</td></tr><tr><td><code>ALTER</code> </td><td>yes
</td></tr><tr><td><code>AND</code> </td><td>yes
</td></tr><tr><td><code>ANY</code> </td><td>yes
</td></tr><tr><td><code>APPLY</code> </td><td>yes
</td></tr><tr><td><code>AS</code> </td><td>no
</td></tr><tr><td><code>ASC</code> </td><td>yes
</td></tr><tr><td><code>ASCII</code> </td><td>no
</td></tr><tr><td><code>AUTHORIZE</code> </td><td>yes
</td></tr><tr><td><code>BATCH</code> </td><td>yes
</td></tr><tr><td><code>BEGIN</code> </td><td>yes
</td></tr><tr><td><code>BIGINT</code> </td><td>no
</td></tr><tr><td><code>BLOB</code> </td><td>no
</td></tr><tr><td><code>BOOLEAN</code> </td><td>no
</td></tr><tr><td><code>BY</code> </td><td>yes
</td></tr><tr><td><code>CLUSTERING</code> </td><td>no
</td></tr><tr><td><code>COLUMNFAMILY</code> </td><td>yes
</td></tr><tr><td><code>COMPACT</code> </td><td>no
</td></tr><tr><td><code>CON
SISTENCY</code> </td><td>no </td></tr><tr><td><code>COUNT</code>
</td><td>no </td></tr><tr><td><code>COUNTER</code> </td><td>no
</td></tr><tr><td><code>CREATE</code> </td><td>yes
</td></tr><tr><td><code>DECIMAL</code> </td><td>no
</td></tr><tr><td><code>DELETE</code> </td><td>yes
</td></tr><tr><td><code>DESC</code> </td><td>yes
</td></tr><tr><td><code>DOUBLE</code> </td><td>no
</td></tr><tr><td><code>DROP</code> </td><td>yes
</td></tr><tr><td><code>EACH_QUORUM</code> </td><td>yes
</td></tr><tr><td><code>FLOAT</code> </td><td>no
</td></tr><tr><td><code>FROM</code> </td><td>yes
</td></tr><tr><td><code>GRANT</code> </td><td>yes
</td></tr><tr><td><code>IN</code> </td><td>yes
</td></tr><tr><td><code>INDEX</code> </td><td>yes
</td></tr><tr><td><code>CUSTOM</code> </td><td>no
</td></tr><tr><td><code>INSERT</code> </td><td>yes
</td></tr><tr><td><code>INT</code> </td><td>no
</td></tr><tr><td><code>INTO</code> </td><td>yes
</td></tr><tr><td><code>KEY</code> </td><td>no
</td></tr><tr><td><code>KEYSPACE</code> </td><td>yes
</td></tr><tr><td><code>LEVEL</code> </td><td>no
</td></tr><tr><td><code>LIMIT</code> </td><td>yes
</td></tr><tr><td><code>LOCAL_ONE</code> </td><td>yes
</td></tr><tr><td><code>LOCAL_QUORUM</code> </td><td>yes
</td></tr><tr><td><code>MODIFY</code> </td><td>yes
</td></tr><tr><td><code>NORECURSIVE</code> </td><td>yes
</td></tr><tr><td><code>NOSUPERUSER</code> </td><td>no
</td></tr><tr><td><code>OF</code> </td><td>yes
</td></tr><tr><td><code>ON</code> </td><td>yes
</td></tr><tr><td><code>ONE</code> </td><td>yes
</td></tr><tr><td><code>ORDER</code> </td><td>yes
</td></tr><tr><td><code>PASSWORD</code> </td><td>no
</td></tr><tr><td><code>PERMISSION</code> </td><td>no
</td></tr><tr><td><code>PERMISSIONS</code> </td><td>no
</td></tr><tr><td><code>PR
IMARY</code> </td><td>yes </td></tr><tr><td><code>QUORUM</code>
</td><td>yes </td></tr><tr><td><code>REVOKE</code> </td><td>yes
</td></tr><tr><td><code>SCHEMA</code> </td><td>yes
</td></tr><tr><td><code>SELECT</code> </td><td>yes
</td></tr><tr><td><code>SET</code> </td><td>yes
</td></tr><tr><td><code>STORAGE</code> </td><td>no
</td></tr><tr><td><code>SUPERUSER</code> </td><td>no
</td></tr><tr><td><code>TABLE</code> </td><td>yes
</td></tr><tr><td><code>TEXT</code> </td><td>no
</td></tr><tr><td><code>TIMESTAMP</code> </td><td>no
</td></tr><tr><td><code>TIMEUUID</code> </td><td>no
</td></tr><tr><td><code>THREE</code> </td><td>yes
</td></tr><tr><td><code>TOKEN</code> </td><td>yes
</td></tr><tr><td><code>TRUNCATE</code> </td><td>yes
</td></tr><tr><td><code>TTL</code> </td><td>no
</td></tr><tr><td><code>TWO</code> </td><td>yes
</td></tr><tr><td><code>TYPE</code> </td><td>n
o </td></tr><tr><td><code>UPDATE</code> </td><td>yes
</td></tr><tr><td><code>USE</code> </td><td>yes
</td></tr><tr><td><code>USER</code> </td><td>no
</td></tr><tr><td><code>USERS</code> </td><td>no
</td></tr><tr><td><code>USING</code> </td><td>yes
</td></tr><tr><td><code>UUID</code> </td><td>no
</td></tr><tr><td><code>VALUES</code> </td><td>no
</td></tr><tr><td><code>VARCHAR</code> </td><td>no
</td></tr><tr><td><code>VARINT</code> </td><td>no
</td></tr><tr><td><code>WHERE</code> </td><td>yes
</td></tr><tr><td><code>WITH</code> </td><td>yes
</td></tr><tr><td><code>WRITETIME</code> </td><td>no
</td></tr><tr><td><code>DISTINCT</code> </td><td>no </td></tr></table><h2
id="appendixB">Appendix B: CQL Reserved Types</h2><p>The following type names
are not currently used by CQL, but are reserved for potential future use.
User-defined types may not use reserved type names as their name.</p><table><t
r><th>type </th></tr><tr><td><code>byte</code>
</td></tr><tr><td><code>smallint</code> </td></tr><tr><td><code>complex</code>
</td></tr><tr><td><code>enum</code> </td></tr><tr><td><code>date</code>
</td></tr><tr><td><code>interval</code>
</td></tr><tr><td><code>macaddr</code>
</td></tr><tr><td><code>bitstring</code> </td></tr></table><h2
id="changes">Changes</h2><p>The following describes the changes in each version
of CQL.</p><h3 id="a3.2.0">3.2.0</h3><ul><li>User-defined types are now
supported through <a href="#createTypeStmt"><code>CREATE TYPE</code></a>, <a
href="#alterTypeStmt"><code>ALTER TYPE</code></a>, and <a
href="#dropTypeStmt"><code>DROP TYPE</code></a></li><li><a
href="#createIndexStmt"><code>CREATE INDEX</code></a> now supports indexing
collection columns, including indexing the keys of map collections through the
<code>keys()</code> function</li><li>Indexes on collections may be queried
using the new <code>CONTAINS</code> and <code>CONTAINS
KEY</code> operators</li><li>Tuple types were added to hold fixed-length sets
of typed positional fields (see the section on <a
href="#types">types</a>)</li><li><a href="#dropIndexStmt"><code>DROP
INDEX</code></a> now supports optionally specifying a keyspace</li></ul><h3
id="a3.1.7">3.1.7</h3><ul><li><code>SELECT</code> statements now support
selecting multiple rows in a single partition using an <code>IN</code> clause
on combinations of clustering columns. See <a href="#selectWhere">SELECT
WHERE</a> clauses.</li><li><code>IF NOT EXISTS</code> and <code>IF
EXISTS</code> syntax is now supported by <code>CREATE USER</code> and
<code>DROP USER</code> statmenets, respectively.</li></ul><h3
id="a3.1.6">3.1.6</h3><ul><li>A new <a href="#uuidFun"><code>uuid</code>
method</a> has been added.</li><li>Support for <code>DELETE ... IF
EXISTS</code> syntax.</li></ul><h3 id="a3.1.5">3.1.5</h3><ul><li>It is now
possible to group clustering columns in a relatiion, see <a
href="#selectWhere">SELEC
T WHERE</a> clauses.</li><li>Added support for <code>STATIC</code> columns,
see <a href="#createTableStatic">static in CREATE TABLE</a>.</li></ul><h3
id="a3.1.4">3.1.4</h3><ul><li><code>CREATE INDEX</code> now allows specifying
options when creating CUSTOM indexes (see <a href="#createIndexStmt">CREATE
INDEX reference</a>).</li></ul><h3 id="a3.1.3">3.1.3</h3><ul><li>Millisecond
precision formats have been added to the timestamp parser (see <a
href="#usingdates">working with dates</a>).</li></ul><h3
id="a3.1.2">3.1.2</h3><ul><li><code>NaN</code> and <code>Infinity</code> has
been added as valid float contants. They are now reserved keywords. In the
unlikely case you we using them as a column identifier (or keyspace/table one),
you will noew need to double quote them (see <a href="#identifiers">quote
identifiers</a>).</li></ul><h3
id="a3.1.1">3.1.1</h3><ul><li><code>SELECT</code> statement now allows listing
the partition keys (using the <code>DISTINCT</code> modifier). See <a href="h
ttps://issues.apache.org/jira/browse/CASSANDRA-4536">CASSANDRA-4536</a>.</li><li>The
syntax <code>c IN ?</code> is now supported in <code>WHERE</code> clauses. In
that case, the value expected for the bind variable will be a list of whatever
type <code>c</code> is.</li><li>It is now possible to use named bind variables
(using <code>:name</code> instead of <code>?</code>).</li></ul><h3
id="a3.1.0">3.1.0</h3><ul><li><a href="#alterTableStmt">ALTER TABLE</a>
<code>DROP</code> option has been reenabled for CQL3 tables and has new
semantics now: the space formerly used by dropped columns will now be
eventually reclaimed (post-compaction). You should not readd previously dropped
columns unless you use timestamps with microsecond precision (see <a
href="https://issues.apache.org/jira/browse/CASSANDRA-3919";>CASSANDRA-3919</a>
for more details).</li><li><code>SELECT</code> statement now supports aliases
in select clause. Aliases in WHERE and ORDER BY clauses are not supported. See
the “
;section on select”#selectStmt for details.</li><li><code>CREATE</code>
statements for <code>KEYSPACE</code>, <code>TABLE</code> and <code>INDEX</code>
now supports an <code>IF NOT EXISTS</code> condition. Similarly,
<code>DROP</code> statements support a <code>IF EXISTS</code>
condition.</li><li><code>INSERT</code> statements optionally supports a
<code>IF NOT EXISTS</code> condition and <code>UPDATE</code> supports
<code>IF</code> conditions.</li></ul><h3
id="a3.0.5">3.0.5</h3><ul><li><code>SELECT</code>, <code>UPDATE</code>, and
<code>DELETE</code> statements now allow empty <code>IN</code> relations (see
<a
href="https://issues.apache.org/jira/browse/CASSANDRA-5626";>CASSANDRA-5626</a>).</li></ul><h3
id="a3.0.4">3.0.4</h3><ul><li>Updated the syntax for custom <a
href="#createIndexStmt">secondary indexes</a>.</li><li>Non-equal condition on
the partition key are now never supported, even for ordering partitioner as
this was not correct (the order was <strong>not</strong> the
one of the type of the partition key). Instead, the <code>token</code> method
should always be used for range queries on the partition key (see <a
href="#selectWhere">WHERE clauses</a>).</li></ul><h3
id="a3.0.3">3.0.3</h3><ul><li>Support for custom <a
href="#createIndexStmt">secondary indexes</a> has been added.</li></ul><h3
id="a3.0.2">3.0.2</h3><ul><li>Type validation for the <a
href="#constants">constants</a> has been fixed. For instance, the
implementation used to allow <code>'2'</code> as a valid value for an
<code>int</code> column (interpreting it has the equivalent of <code>2</code>),
or <code>42</code> as a valid <code>blob</code> value (in which case
<code>42</code> was interpreted as an hexadecimal representation of the blob).
This is no longer the case, type validation of constants is now more strict.
See the <a href="#types">data types</a> section for details on which constant
is allowed for which type.</li><li>The type validation fixed of the previous
point has lead to
the introduction of <a href="#constants">blobs constants</a> to allow
inputing blobs. Do note that while inputing blobs as strings constant is still
supported by this version (to allow smoother transition to blob constant), it
is now deprecated (in particular the <a href="#types">data types</a> section
does not list strings constants as valid blobs) and will be removed by a future
version. If you were using strings as blobs, you should thus update your client
code ASAP to switch blob constants.</li><li>A number of functions to convert
native types to blobs have also been introduced. Furthermore the token function
is now also allowed in select clauses. See the <a href="#functions">section on
functions</a> for details.</li></ul><h3 id="a3.0.1">3.0.1</h3><ul><li><a
href="#usingdates">Date strings</a> (and timestamps) are no longer accepted as
valid <code>timeuuid</code> values. Doing so was a bug in the sense that date
string are not valid <code>timeuuid</code>, and it was thus result
ing in <a
href="https://issues.apache.org/jira/browse/CASSANDRA-4936";>confusing
behaviors</a>. However, the following new methods have been added to help
working with <code>timeuuid</code>: <code>now</code>, <code>minTimeuuid</code>,
<code>maxTimeuuid</code> , <code>dateOf</code> and
<code>unixTimestampOf</code>. See the <a href="#usingtimeuuid">section
dedicated to these methods</a> for more detail.</li><li>“Float
constants”#constants now support the exponent notation. In other words,
<code>4.2E10</code> is now a valid floating point value.</li></ul><h2
id="Versioning">Versioning</h2><p>Versioning of the CQL language adheres to the
<a href="http://semver.org";>Semantic Versioning</a> guidelines. Versions take
the form X.Y.Z where X, Y, and Z are integer values representing major, minor,
and patch level respectively. There is no correlation between Cassandra release
versions and the CQL language
version.</p><table><tr><th>version</th><th>description</th></tr><tr><td>Majo
r </td><td>The major version <em>must</em> be bumped when backward
incompatible changes are introduced. This should rarely
occur.</td></tr><tr><td>Minor </td><td>Minor version increments occur when
new, but backward compatible, functionality is
introduced.</td></tr><tr><td>Patch </td><td>The patch version is
incremented when bugs are fixed.</td></tr></table></body></html>
\ No newline at end of file
+</pre></pre> <p>will select all rows where the <code>timeuuid</code> column
<code>t</code> is strictly older than ‘2013-01-01 00:05+0000’ but
strictly younger than ‘2013-02-02 10:00+0000’. Please note that
<code>t >= maxTimeuuid('2013-01-01 00:05+0000')</code> would still <em>not</em>
select a <code>timeuuid</code> generated exactly at ‘2013-01-01
00:05+0000’ and is essentially equivalent to <code>t >
maxTimeuuid('2013-01-01 00:05+0000')</code>.</p><p><em>Warning</em>: We called
the values generated by <code>minTimeuuid</code> and <code>maxTimeuuid</code>
<em>fake</em> UUID because they do no respect the Time-Based UUID generation
process specified by the <a href="http://www.ietf.org/rfc/rfc4122.txt";>RFC
4122</a>. In particular, the value returned by these 2 methods will not be
unique. This means you should only use those methods for querying (as in the
example above). Inserting the result of those methods is almost certainly <em>a
bad idea</em>.
</p><h4 id="dateOfandunixTimestampOf"><code>dateOf</code> and
<code>unixTimestampOf</code></h4><p>The <code>dateOf</code> and
<code>unixTimestampOf</code> functions take a <code>timeuuid</code> argument
and extract the embedded timestamp. However, while the <code>dateof</code>
function return it with the <code>timestamp</code> type (that most client,
including cqlsh, interpret as a date), the <code>unixTimestampOf</code>
function returns it as a <code>bigint</code> raw value.</p><h3
id="blobFun">Blob conversion functions</h3><p>A number of functions are
provided to “convert” the native types into binary data
(<code>blob</code>). For every <code><native-type></code> <code>type</code>
supported by CQL3 (a notable exceptions is <code>blob</code>, for obvious
reasons), the function <code>typeAsBlob</code> takes a argument of type
<code>type</code> and return it as a <code>blob</code>. Conversely, the
function <code>blobAsType</code> takes a 64-bit <code>blob</code> argum
ent and convert it to a <code>bigint</code> value. And so for instance,
<code>bigintAsBlob(3)</code> is <code>0x0000000000000003</code> and
<code>blobAsBigint(0x0000000000000003)</code> is <code>3</code>.</p><h2
id="appendixA">Appendix A: CQL Keywords</h2><p>CQL distinguishes between
<em>reserved</em> and <em>non-reserved</em> keywords. Reserved keywords cannot
be used as identifier, they are truly reserved for the language (but one can
enclose a reserved keyword by double-quotes to use it as an identifier).
Non-reserved keywords however only have a specific meaning in certain context
but can used as identifer otherwise. The only <em>raison d'être</em> of these
non-reserved keywords is convenience: some keyword are non-reserved when it was
always easy for the parser to decide whether they were used as keywords or
not.</p><table><tr><th>Keyword </th><th>Reserved?
</th></tr><tr><td><code>ADD</code> </td><td>yes
</td></tr><tr><td><code>ALL</code> </td><td>no
</td></tr><tr><td><code>ALTER</code> </td><td>yes
</td></tr><tr><td><code>AND</code> </td><td>yes
</td></tr><tr><td><code>ANY</code> </td><td>yes
</td></tr><tr><td><code>APPLY</code> </td><td>yes
</td></tr><tr><td><code>AS</code> </td><td>no
</td></tr><tr><td><code>ASC</code> </td><td>yes
</td></tr><tr><td><code>ASCII</code> </td><td>no
</td></tr><tr><td><code>AUTHORIZE</code> </td><td>yes
</td></tr><tr><td><code>BATCH</code> </td><td>yes
</td></tr><tr><td><code>BEGIN</code> </td><td>yes
</td></tr><tr><td><code>BIGINT</code> </td><td>no
</td></tr><tr><td><code>BLOB</code> </td><td>no
</td></tr><tr><td><code>BOOLEAN</code> </td><td>no
</td></tr><tr><td><code>BY</code> </td><td>yes
</td></tr><tr><td><code>CLUSTERING</code> </td><td>no
</td></tr><tr><td><code>COLUMNFAMILY</code> </td><td>yes
</td></tr><tr><td><code>COMPACT</code> </td><td>no
</td></tr><tr><td><code>CON
SISTENCY</code> </td><td>no </td></tr><tr><td><code>COUNT</code>
</td><td>no </td></tr><tr><td><code>COUNTER</code> </td><td>no
</td></tr><tr><td><code>CREATE</code> </td><td>yes
</td></tr><tr><td><code>DECIMAL</code> </td><td>no
</td></tr><tr><td><code>DELETE</code> </td><td>yes
</td></tr><tr><td><code>DESC</code> </td><td>yes
</td></tr><tr><td><code>DOUBLE</code> </td><td>no
</td></tr><tr><td><code>DROP</code> </td><td>yes
</td></tr><tr><td><code>EACH_QUORUM</code> </td><td>yes
</td></tr><tr><td><code>FLOAT</code> </td><td>no
</td></tr><tr><td><code>FROM</code> </td><td>yes
</td></tr><tr><td><code>GRANT</code> </td><td>yes
</td></tr><tr><td><code>IN</code> </td><td>yes
</td></tr><tr><td><code>INDEX</code> </td><td>yes
</td></tr><tr><td><code>CUSTOM</code> </td><td>no
</td></tr><tr><td><code>INSERT</code> </td><td>yes
</td></tr><tr><td><code>INT</code> </td><td>no
</td></tr><tr><td><code>INTO</code> </td><td>yes
</td></tr><tr><td><code>KEY</code> </td><td>no
</td></tr><tr><td><code>KEYSPACE</code> </td><td>yes
</td></tr><tr><td><code>LEVEL</code> </td><td>no
</td></tr><tr><td><code>LIMIT</code> </td><td>yes
</td></tr><tr><td><code>LOCAL_ONE</code> </td><td>yes
</td></tr><tr><td><code>LOCAL_QUORUM</code> </td><td>yes
</td></tr><tr><td><code>MODIFY</code> </td><td>yes
</td></tr><tr><td><code>NORECURSIVE</code> </td><td>yes
</td></tr><tr><td><code>NOSUPERUSER</code> </td><td>no
</td></tr><tr><td><code>OF</code> </td><td>yes
</td></tr><tr><td><code>ON</code> </td><td>yes
</td></tr><tr><td><code>ONE</code> </td><td>yes
</td></tr><tr><td><code>ORDER</code> </td><td>yes
</td></tr><tr><td><code>PASSWORD</code> </td><td>no
</td></tr><tr><td><code>PERMISSION</code> </td><td>no
</td></tr><tr><td><code>PERMISSIONS</code> </td><td>no
</td></tr><tr><td><code>PR
IMARY</code> </td><td>yes </td></tr><tr><td><code>QUORUM</code>
</td><td>yes </td></tr><tr><td><code>REVOKE</code> </td><td>yes
</td></tr><tr><td><code>SCHEMA</code> </td><td>yes
</td></tr><tr><td><code>SELECT</code> </td><td>yes
</td></tr><tr><td><code>SET</code> </td><td>yes
</td></tr><tr><td><code>STORAGE</code> </td><td>no
</td></tr><tr><td><code>SUPERUSER</code> </td><td>no
</td></tr><tr><td><code>TABLE</code> </td><td>yes
</td></tr><tr><td><code>TEXT</code> </td><td>no
</td></tr><tr><td><code>TIMESTAMP</code> </td><td>no
</td></tr><tr><td><code>TIMEUUID</code> </td><td>no
</td></tr><tr><td><code>THREE</code> </td><td>yes
</td></tr><tr><td><code>TOKEN</code> </td><td>yes
</td></tr><tr><td><code>TRUNCATE</code> </td><td>yes
</td></tr><tr><td><code>TTL</code> </td><td>no
</td></tr><tr><td><code>TWO</code> </td><td>yes
</td></tr><tr><td><code>TYPE</code> </td><td>n
o </td></tr><tr><td><code>UPDATE</code> </td><td>yes
</td></tr><tr><td><code>USE</code> </td><td>yes
</td></tr><tr><td><code>USER</code> </td><td>no
</td></tr><tr><td><code>USERS</code> </td><td>no
</td></tr><tr><td><code>USING</code> </td><td>yes
</td></tr><tr><td><code>UUID</code> </td><td>no
</td></tr><tr><td><code>VALUES</code> </td><td>no
</td></tr><tr><td><code>VARCHAR</code> </td><td>no
</td></tr><tr><td><code>VARINT</code> </td><td>no
</td></tr><tr><td><code>WHERE</code> </td><td>yes
</td></tr><tr><td><code>WITH</code> </td><td>yes
</td></tr><tr><td><code>WRITETIME</code> </td><td>no
</td></tr><tr><td><code>DISTINCT</code> </td><td>no </td></tr></table><h2
id="appendixB">Appendix B: CQL Reserved Types</h2><p>The following type names
are not currently used by CQL, but are reserved for potential future use.
User-defined types may not use reserved type names as their name.</p><table><t
r><th>type </th></tr><tr><td><code>byte</code>
</td></tr><tr><td><code>smallint</code> </td></tr><tr><td><code>complex</code>
</td></tr><tr><td><code>enum</code> </td></tr><tr><td><code>date</code>
</td></tr><tr><td><code>interval</code>
</td></tr><tr><td><code>macaddr</code>
</td></tr><tr><td><code>bitstring</code> </td></tr></table><h2
id="changes">Changes</h2><p>The following describes the changes in each version
of CQL.</p><h3 id="a3.2.1">3.2.1</h3><ul><li>The syntax <code>TRUNCATE TABLE
X</code> is now accepted as an alias for <code>TRUNCATE X</code></li></ul><h3
id="a3.2.0">3.2.0</h3><ul><li>User-defined types are now supported through <a
href="#createTypeStmt"><code>CREATE TYPE</code></a>, <a
href="#alterTypeStmt"><code>ALTER TYPE</code></a>, and <a
href="#dropTypeStmt"><code>DROP TYPE</code></a></li><li><a
href="#createIndexStmt"><code>CREATE INDEX</code></a> now supports indexing
collection columns, including indexing the keys of map collections th
rough the <code>keys()</code> function</li><li>Indexes on collections may be
queried using the new <code>CONTAINS</code> and <code>CONTAINS KEY</code>
operators</li><li>Tuple types were added to hold fixed-length sets of typed
positional fields (see the section on <a href="#types">types</a>)</li><li><a
href="#dropIndexStmt"><code>DROP INDEX</code></a> now supports optionally
specifying a keyspace</li></ul><h3
id="a3.1.7">3.1.7</h3><ul><li><code>SELECT</code> statements now support
selecting multiple rows in a single partition using an <code>IN</code> clause
on combinations of clustering columns. See <a href="#selectWhere">SELECT
WHERE</a> clauses.</li><li><code>IF NOT EXISTS</code> and <code>IF
EXISTS</code> syntax is now supported by <code>CREATE USER</code> and
<code>DROP USER</code> statmenets, respectively.</li></ul><h3
id="a3.1.6">3.1.6</h3><ul><li>A new <a href="#uuidFun"><code>uuid</code>
method</a> has been added.</li><li>Support for <code>DELETE ... IF
EXISTS</code> syntax
.</li></ul><h3 id="a3.1.5">3.1.5</h3><ul><li>It is now possible to group
clustering columns in a relatiion, see <a href="#selectWhere">SELECT WHERE</a>
clauses.</li><li>Added support for <code>STATIC</code> columns, see <a
href="#createTableStatic">static in CREATE TABLE</a>.</li></ul><h3
id="a3.1.4">3.1.4</h3><ul><li><code>CREATE INDEX</code> now allows specifying
options when creating CUSTOM indexes (see <a href="#createIndexStmt">CREATE
INDEX reference</a>).</li></ul><h3 id="a3.1.3">3.1.3</h3><ul><li>Millisecond
precision formats have been added to the timestamp parser (see <a
href="#usingdates">working with dates</a>).</li></ul><h3
id="a3.1.2">3.1.2</h3><ul><li><code>NaN</code> and <code>Infinity</code> has
been added as valid float contants. They are now reserved keywords. In the
unlikely case you we using them as a column identifier (or keyspace/table one),
you will noew need to double quote them (see <a href="#identifiers">quote
identifiers</a>).</li></ul><h3 id="a3.1.1">3.1.
1</h3><ul><li><code>SELECT</code> statement now allows listing the partition
keys (using the <code>DISTINCT</code> modifier). See <a
href="https://issues.apache.org/jira/browse/CASSANDRA-4536";>CASSANDRA-4536</a>.</li><li>The
syntax <code>c IN ?</code> is now supported in <code>WHERE</code> clauses. In
that case, the value expected for the bind variable will be a list of whatever
type <code>c</code> is.</li><li>It is now possible to use named bind variables
(using <code>:name</code> instead of <code>?</code>).</li></ul><h3
id="a3.1.0">3.1.0</h3><ul><li><a href="#alterTableStmt">ALTER TABLE</a>
<code>DROP</code> option has been reenabled for CQL3 tables and has new
semantics now: the space formerly used by dropped columns will now be
eventually reclaimed (post-compaction). You should not readd previously dropped
columns unless you use timestamps with microsecond precision (see <a
href="https://issues.apache.org/jira/browse/CASSANDRA-3919";>CASSANDRA-3919</a>
for more details).</li><li>
<code>SELECT</code> statement now supports aliases in select clause. Aliases
in WHERE and ORDER BY clauses are not supported. See the “section on
select”#selectStmt for details.</li><li><code>CREATE</code> statements
for <code>KEYSPACE</code>, <code>TABLE</code> and <code>INDEX</code> now
supports an <code>IF NOT EXISTS</code> condition. Similarly, <code>DROP</code>
statements support a <code>IF EXISTS</code>
condition.</li><li><code>INSERT</code> statements optionally supports a
<code>IF NOT EXISTS</code> condition and <code>UPDATE</code> supports
<code>IF</code> conditions.</li></ul><h3
id="a3.0.5">3.0.5</h3><ul><li><code>SELECT</code>, <code>UPDATE</code>, and
<code>DELETE</code> statements now allow empty <code>IN</code> relations (see
<a
href="https://issues.apache.org/jira/browse/CASSANDRA-5626";>CASSANDRA-5626</a>).</li></ul><h3
id="a3.0.4">3.0.4</h3><ul><li>Updated the syntax for custom <a
href="#createIndexStmt">secondary indexes</a>.</li><li>Non-equal condition
on the partition key are now never supported, even for ordering partitioner as
this was not correct (the order was <strong>not</strong> the one of the type of
the partition key). Instead, the <code>token</code> method should always be
used for range queries on the partition key (see <a href="#selectWhere">WHERE
clauses</a>).</li></ul><h3 id="a3.0.3">3.0.3</h3><ul><li>Support for custom <a
href="#createIndexStmt">secondary indexes</a> has been added.</li></ul><h3
id="a3.0.2">3.0.2</h3><ul><li>Type validation for the <a
href="#constants">constants</a> has been fixed. For instance, the
implementation used to allow <code>'2'</code> as a valid value for an
<code>int</code> column (interpreting it has the equivalent of <code>2</code>),
or <code>42</code> as a valid <code>blob</code> value (in which case
<code>42</code> was interpreted as an hexadecimal representation of the blob).
This is no longer the case, type validation of constants is now more strict.
See the <a href="#types">data ty
pes</a> section for details on which constant is allowed for which
type.</li><li>The type validation fixed of the previous point has lead to the
introduction of <a href="#constants">blobs constants</a> to allow inputing
blobs. Do note that while inputing blobs as strings constant is still supported
by this version (to allow smoother transition to blob constant), it is now
deprecated (in particular the <a href="#types">data types</a> section does not
list strings constants as valid blobs) and will be removed by a future version.
If you were using strings as blobs, you should thus update your client code
ASAP to switch blob constants.</li><li>A number of functions to convert native
types to blobs have also been introduced. Furthermore the token function is now
also allowed in select clauses. See the <a href="#functions">section on
functions</a> for details.</li></ul><h3 id="a3.0.1">3.0.1</h3><ul><li><a
href="#usingdates">Date strings</a> (and timestamps) are no longer accepted as
vali
d <code>timeuuid</code> values. Doing so was a bug in the sense that date
string are not valid <code>timeuuid</code>, and it was thus resulting in <a
href="https://issues.apache.org/jira/browse/CASSANDRA-4936";>confusing
behaviors</a>. However, the following new methods have been added to help
working with <code>timeuuid</code>: <code>now</code>, <code>minTimeuuid</code>,
<code>maxTimeuuid</code> , <code>dateOf</code> and
<code>unixTimestampOf</code>. See the <a href="#usingtimeuuid">section
dedicated to these methods</a> for more detail.</li><li>“Float
constants”#constants now support the exponent notation. In other words,
<code>4.2E10</code> is now a valid floating point value.</li></ul><h2
id="Versioning">Versioning</h2><p>Versioning of the CQL language adheres to the
<a href="http://semver.org";>Semantic Versioning</a> guidelines. Versions take
the form X.Y.Z where X, Y, and Z are integer values representing major, minor,
and patch level respectively. There is no corr
elation between Cassandra release versions and the CQL language
version.</p><table><tr><th>version</th><th>description</th></tr><tr><td>Major
</td><td>The major version <em>must</em> be bumped when backward incompatible
changes are introduced. This should rarely occur.</td></tr><tr><td>Minor
</td><td>Minor version increments occur when new, but backward compatible,
functionality is introduced.</td></tr><tr><td>Patch </td><td>The patch
version is incremented when bugs are fixed.</td></tr></table></body></html>
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