ated.. [was: Re: [EXTERNAL]
No such column error]
OK i must have must the posts from the 12th of March till the end of that week
, being busy with other things.....
On 24-3-2020 09:19, Hick Gunter wrote:
> See announcement on the mailing list dated march 12th
>
> -Ursprüngl
See announcement on the mailing list dated march 12th
-Ursprüngliche Nachricht-
Von: sqlite-users [mailto:sqlite-users-boun...@mailinglists.sqlite.org] Im
Auftrag von Richard Hipp
Gesendet: Donnerstag, 12. März 2020 21:18
An: General Discussion of SQLite Database
Betreff: [EXTERNAL]
The mailing list is deprecated. You need to go to https://sqlite.org/forum/ for
the sqlite forum.
Can you replicate the problem while using the sqlite shell? Are you checking
column names returned from the second statement? Note that a.BIRTH.YYY from
your example looks a bit weird for a
Exactly what I gained from the EXPLAIN output.
The SQL "compiler" is extracting the constant expression ABS(...) and
evaluating it in the program prolog (where schema is checked and locks taken).
See instructions 11 and 12
asql> explain select coalesce((SELECT
While ORACLE does state that COALESCE will short circuit, SQLite does not.
May I suggest implementing your own user defined function to do this instead.
void THROW_IF_NULL(
sqlite3_context *ctx,
int argc,
sqlite3_value**argv) {
int ii;
for( ii == 0; ii < argc; ii++)
{
It is possible to infer, from the EXPLAIN output, that the SQLite program
generator attempts to isolate constant expressions and evaluates them first,
before it enters the COALESCE loop.
From my experience in reading SQL Programs, the general structure is
GOTO INIT
START:
- load constant
-Ursprüngliche Nachricht-
Von: sqlite-users [mailto:sqlite-users-boun...@mailinglists.sqlite.org] Im
Auftrag von Hick Gunter
Gesendet: Donnerstag, 5. März 2020 08:48
An: SQLite mailing list
Betreff: Re: [sqlite] [EXTERNAL] Inconsistency of CREATE/DROP TABLE with
attached DBs
I don't see any
I don't see any inconsistency here.
1) implicit attach of a.sqlite as main and create a.t1
2) implcit attach b.sqlite as main, attach a.sqlite as a and create (main).t1
(in b.sqlite)
3) implicit attach c.sqlite as main, attaxh a.sqlite as a and drop the only
table named t1 from a
c.sqlite
SQLite is not a procedural language. IF is not a programming construct, it is
part of an expression.
-Ursprüngliche Nachricht-
Von: sqlite-users [mailto:sqlite-users-boun...@mailinglists.sqlite.org] Im
Auftrag von Andy KU7T
Gesendet: Montag, 24. Februar 2020 05:17
An: SQLite mailing
Round(1299.6) returns the floating point number 1300.0,
passing 1300.0 to the rtrim function converts it tot he string '1300.0'
removing all '.' and '0' characters from '1300.0' yields 13
This is no suprise
-Ursprüngliche Nachricht-
Von: sqlite-users
The next value for an INTEGER PRIMARY KEY AUTOINCREMENT does not depend on the
current contents of the table, only its history. While ROWIDs are monotnically
increasing, there may be gaps in the sequence, caused by rows that failed to
insert due to constraint violations. However, ROWIDs that
>Von: sqlite-users [mailto:sqlite-users-boun...@mailinglists.sqlite.org] Im
>Auftrag von Jens Alfke
>> On Feb 12, 2020, at 5:30 AM, Hick Gunter wrote:
>>
>> This is documented here https://sqlite.org/partialindex.html
>> <https://sqlite.org/partialindex.htm
This is documented here https://sqlite.org/partialindex.html and here
https://sqlite.org/queryplanner.html
Specifically, SQLIte does not prove theorems in first-order logic.
To have a chance of using the partial indices, you would need to have your
query translator formulate (expr1>val1 AND
>Von: sqlite-users [mailto:sqlite-users-boun...@mailinglists.sqlite.org] Im
>Auftrag von Dominique Devienne
>
>On Thu, Feb 6, 2020 at 9:32 AM Hick Gunter wrote:
>> >Of course, it may be that the writer of the VTable should know what they
>> >are doing an
list
Betreff: Re: [sqlite] [EXTERNAL] Re: Patch: VTable Column Affinity Question and
Change Request
Hick Gunter wrote on Thursday, February 6, 2020 3:32 AM
>We are almost exclusively using virtual tables to allow queries against
>our internal data sources, which are C language structs an
>Von: sqlite-users [mailto:sqlite-users-boun...@mailinglists.sqlite.org] Im
>Auftrag von Keith Medcalf
>Betreff: [EXTERNAL] Re: [sqlite] Patch: VTable Column Affinity Question and
>Change Request
>
>
>Patch to Fix Column Affinity not applied to Virtual Columns.
>
>In expr.c function
Visit the link given at the bottom of every message, including this one
-Ursprüngliche Nachricht-
Von: sqlite-users [mailto:sqlite-users-boun...@mailinglists.sqlite.org] Im
Auftrag von Ainhoa B
Gesendet: Mittwoch, 5. Februar 2020 15:11
An: SQLite mailing list
Betreff: [EXTERNAL]
WHERE x IN carray($PTR, $DIM)
With $PTR being the address of the array and $DIM ist cardinality. Should be
tons faster than parsing and binding a gazillion parameters.
-Ursprüngliche Nachricht-
Von: sqlite-users [mailto:sqlite-users-boun...@mailinglists.sqlite.org] Im
Auftrag von Deon
"Autocommit" means that each SQL Statement executes in it's own transaction.
Just as if you were to execute "begin; ; commit;" each time.
-Ursprüngliche Nachricht-
Von: sqlite-users [mailto:sqlite-users-boun...@mailinglists.sqlite.org] Im
Auftrag von Peng Yu
Gesendet: Freitag, 31.
You have fallen into the double quote trap.
SQLite uses double quotes to denote COLUMN NAMES, and single quotes to delimit
STRING CONSTANTS.
When asking for "M" or "G", you get the contents of the column named m and g
respectively (column names are case insensitive).
When asking for "P" or
If you could provide more information then maybe someone can suggest a reason
or even a solution for the effect you are seeing. Some of the following may be
helpful.
What schema are you using?
Which journal mode is your database running in?
What kind of statements are executed?
How are you
You are missing
maxsize += _varIntSize_(maxsize)
fort he size varint at the begin oft he header just before the return
-Ursprüngliche Nachricht-
Von: sqlite-users [mailto:sqlite-users-boun...@mailinglists.sqlite.org] Im
Auftrag von Keith Medcalf
Gesendet: Montag, 27. Januar 2020 12:43
As previously mentioned, SQLite uses a compressed format to store rows. You
would have to reverse engineer at least the calculation
-Ursprüngliche Nachricht-
Von: sqlite-users [mailto:sqlite-users-boun...@mailinglists.sqlite.org] Im
Auftrag von Deon Brewis
Gesendet: Samstag, 25. Januar
SQLite uses a compressed format to store records (be it rows of a table or
entries in an index), so the length of a specific record depends on its
contents.
See https://sqlite.org/fileformat.html
Storing a row of (NULL, NULL, NULL, NULL) takes just 5 bytes, whereas (1024,
1.234, 'some
> Obviously the character(s) responsible for dates etc were NOT C programmers!
No, they still using Roman Numerals instead of Indian Numbers and were
oblivious of the number 0. As indeed Abu Dschaʿfar Muhammad ibn Musa
al-Chwārizmī published his book "De numero Indorum" (the earliest latin
You need an UPDATE trigger for this, since the comparison requires knowledge of
the old and new values.
-Ursprüngliche Nachricht-
Von: sqlite-users [mailto:sqlite-users-boun...@mailinglists.sqlite.org] Im
Auftrag von Cecil Westerhof
Gesendet: Freitag, 27. Dezember 2019 13:05
An: SQLite
No. You need the BTree and table code to handle the sqlite3_master table.
-Ursprüngliche Nachricht-
Von: sqlite-users [mailto:sqlite-users-boun...@mailinglists.sqlite.org] Im
Auftrag von Jens Alfke
Gesendet: Samstag, 21. Dezember 2019 19:50
An: SQLite mailing list
Betreff: [EXTERNAL]
Any statement that has been stepped but not to completion will hold open the
transaction on a connection. This may interfere with your expectations.
Clearing bindings as a precaution will prevent inadvertent re-use of old
bindings. The statement may have to be reset first, see documentation.
The X'' notation returns a blob. LIKE works with strings. Comparing a string to
a blob of the same content always returns false.
-Ursprüngliche Nachricht-
Von: sqlite-users [mailto:sqlite-users-boun...@mailinglists.sqlite.org] Im
Auftrag von Sascha Ziemann
Gesendet: Freitag, 13.
Think about same column names in distinct tables within the same select and
then throw in a couple of AS clauses and maybe an SQL parameter.
-Ursprüngliche Nachricht-
Von: sqlite-users [mailto:sqlite-users-boun...@mailinglists.sqlite.org] Im
Auftrag von Doug
Gesendet: Dienstag, 10.
If your external data store can maintain an index on some expression, then
exposing that index as a computed field is the way to go with a virtual table.
Alternatively, you can expose the index as a separate virtual table with a
"foreign key" that references the original virtual table and join
You are using text columns as primary keys and referencing them directly in
foreign keys. This is probably not what you want, because it duplicates the
text key. Also, with foreign keys enabled, your join is not accomplishing
anything more than a direct select from joining_table, just with more
What is the use case?
The statement you give will set the value of the "column" field of table
"table" to the whole contents of file.txt in each and every row that matches
SQLite does not have a symbolic link type. You can store the text of a symbolic
link, but accessing the contents would
CSV is unable to represent the NULL value. The best it can do is "empty
string", which gets converted to - drumroll - an empty string (or the value 0
for numeric fields).
The field names you are using suggest that you may have not sufficiently
normalized your data, since you have duplicated
The Magic Max at work, forcing the query to return at least one record.
-Ursprüngliche Nachricht-
Von: sqlite-users [mailto:sqlite-users-boun...@mailinglists.sqlite.org] Im
Auftrag von Jose Isaias Cabrera
Gesendet: Montag, 18. November 2019 20:11
An: 'SQLite mailing list'
Betreff:
Nothing. The select returns no rows so no rows are inserted.
-Ursprüngliche Nachricht-
Von: sqlite-users [mailto:sqlite-users-boun...@mailinglists.sqlite.org] Im
Auftrag von Doug
Gesendet: Freitag, 15. November 2019 17:42
An: 'SQLite mailing list'
Betreff: [EXTERNAL] Re: [sqlite]
>> A growing number of organisations now ask me for my DOB or my
>> postcode, rather than my name, when looking me up. I think you just
>> explained why. In my country we have an increasing number of foreign
>> family names, which probably helps it along.
>
>UK postcodes are incredibly
Maybe you are confusing the autoindex logic by including superflous attributes:
... Id INTEGER NOT NULL PRIMARY KEY UNIQUE ...
NOT NULL is enforced for WITHOUT ROWID tables and a single field PRIMARY KEY
already implies UNIQUE, so no autoindex is required for Id
This leaves only the autoindex
>What about if I want 1 hour granity? (to plot a graph of daily consumption for
>example)
For a (meaningful, as opposed to "all interpolated values") granularity of 1
hour, information theory states that you need a sample every 30 minutes or less.
The desire to charge consumers more for "peak
The "virtual table playground gadget" was our primary reason for selecting
SQLite in the first place, because none of our production data sources are
native SQLite tables. Instead, we have about 20 virtual table modules that
implement about 1000 virtual table instances.
-Ursprüngliche
to construct one "original" row will be
faster? So not sure if I understand why reading and decoding cells in over
multiple columns is so much slower than reading and decoding cells in over
multiple rows?
Mitar
On Thu, Oct 17, 2019 at 3:38 PM Hick Gunter wrote:
>
> I hav
er
multiple columns is so much slower than reading and decoding cells in over
multiple rows?
Mitar
On Thu, Oct 17, 2019 at 3:38 PM Hick Gunter wrote:
>
> I have the impression that you still do not grasp the folly of a 100k column
> schema.
>
> See the example below, which only
I have the impression that you still do not grasp the folly of a 100k column
schema.
See the example below, which only has 6 fields. As you can see, each field
requires a Column opcode and arguments (about 10 bytes) and a "register" to
hold the value (48 bytes), which for 100k columns uses
Since your data is at least mostly opaque in the sense that SQLite is not
expected to interpret the contents, why not split your data into "stuff you
want to query ins SQLite" and "stuff you want to just store"? The former means
individual columns, whereas the latter could be stored in a single
Decker
Gesendet: Donnerstag, 17. Oktober 2019 08:24
An: SQLite mailing list
Betreff: Re: [sqlite] [EXTERNAL] Limit on number of columns in SQLite table
On Wed, Oct 16, 2019 at 11:03 AM Mitar wrote:
> Hi!
>
> On Wed, Oct 16, 2019 at 3:16 PM Hick Gunter wrote:
> > 100k distin
mailing list
Betreff: Re: [sqlite] [EXTERNAL] Limit on number of columns in SQLite table
Hi!
On Wed, Oct 16, 2019 at 3:16 PM Hick Gunter wrote:
> 100k distinct column names? Or is that 1 repeats of 10 attributes?
100k distinct names. Like each column a different gene expression.
Mi
100k distinct column names? Or is that 1 repeats of 10 attributes?
-Ursprüngliche Nachricht-
Von: sqlite-users [mailto:sqlite-users-boun...@mailinglists.sqlite.org] Im
Auftrag von Mitar
Gesendet: Mittwoch, 16. Oktober 2019 14:57
An: sqlite-users@mailinglists.sqlite.org
Betreff:
Then the first peanut may well be the last one, irrespective of the cardinality
of the tin.
-Ursprüngliche Nachricht-
Von: sqlite-users [mailto:sqlite-users-boun...@mailinglists.sqlite.org] Im
Auftrag von Don V Nielsen
Gesendet: Dienstag, 15. Oktober 2019 21:52
An: SQLite mailing list
The order of rows returned by a query is undefined - i.e. from the point of
view of the application, a random member of the result set will be returned
last - unless you include an ORDER BY clause that uniquely defines the order of
the records to be returned. Given the latter, it is easy to
You are getting exactly what is documented and exactly what you asked for.
Declaring a column NUMERIC means you intend to store NUMBERS. Leading zeros do
not change the value of a number. 0012 == 12 unless you have a convention of
interpreting a leading zero as indicating octal base.
If you
What it boils down to is asking the data storage layer to perform a
presentation layer task.
If you insist on solving the problem inside an SQL statement, you can always
write your own extension function to "easily" perform the necessary conversion.
-Ursprüngliche Nachricht-
Von:
I'm guessing that LOCALE_NOCASE will probably be causing things that collate
distinct in NOCASE to collate equal, so the risk of breaking UNIQUE constraints
seems rather small
-Ursprüngliche Nachricht-
Von: sqlite-users [mailto:sqlite-users-boun...@mailinglists.sqlite.org] Im
Auftrag
You can't have a variable inside a pattern. Use like '%' || ? || '%'
-Ursprüngliche Nachricht-
Von: sqlite-users [mailto:sqlite-users-boun...@mailinglists.sqlite.org] Im
Auftrag von Daniel Odom
Gesendet: Donnerstag, 26. September 2019 15:26
An: sqlite-users@mailinglists.sqlite.org
t
Betreff: Re: [sqlite] [EXTERNAL] Group-by and order-by-desc does not work as
expected
On Thu, Sep 19, 2019 at 6:15 PM Hick Gunter wrote:
> -Ursprüngliche Nachricht-
> Von: sqlite-users
> [mailto:sqlite-users-boun...@mailinglists.sqlite.org]
> Im Auftrag von Fredrik Larsen
-Ursprüngliche Nachricht-
Von: sqlite-users [mailto:sqlite-users-boun...@mailinglists.sqlite.org] Im
Auftrag von Fredrik Larsen
Gesendet: Donnerstag, 19. September 2019 17:29
An: SQLite mailing list
Betreff: Re: [sqlite] [EXTERNAL] Group-by and order-by-desc does not work as
expected
An ORDER BY clause will omit sorting only if the visitation order exactly
fulfills the clause.
A GROUP BY clause is able to avoid creating a temporary table if the visitation
order exactly fulfills the clause.
If a SELECT references only fields present in an index, that (covering) index
may
The mathlab function setdiff(a,b) returns the rows from a that are not in b.
The equivalent SQL (assuming identical tables a and b) would be
SELECT FROM a EXCEPT SELECT FROM b
You can then
INSERT INTO b SELECT * FROM a WHERE IN (SELECT FROM
a EXCEPT SELECT FROM b);
DELETE FROM a WHERE
This is well documented in https://sqlite.org/datatypes.html and
https://sqlite.org/datatype3.html
-Ursprüngliche Nachricht-
Von: sqlite-users [mailto:sqlite-users-boun...@mailinglists.sqlite.org] Im
Auftrag von kapil
Gesendet: Samstag, 14. September 2019 11:15
An:
WITH list (key) AS (VALUES (mailto:sqlite-users-boun...@mailinglists.sqlite.org] Im
Auftrag von Jens Alfke
Gesendet: Freitag, 13. September 2019 18:39
An: SQLite mailing list
Betreff: [EXTERNAL] [sqlite] Fastest way to SELECT on a set of keys?
If I have a set of primary keys (let's say a few
While a write transaction is open, SQLite needs to keep the changed pages in
memory. When the size of a transaction (measured in changed pages) exceeds the
available memory, SQLite starts to spill the transaction to disk. The optimal
transaction size would be just before this occurs, but there
BTrees as per concept are aware of sorted load vs random load and will adjust
their node splitting algorithm accordingly (e.g. 90/10 split for ordered and
50/50 for random load). The rationale being that an ordered load tends to
indicate that new data is unlikely or added at the end, whereas a
Does your "parent" relationship contain (at least one) loop(s)? UNION will
break the loop by eliminating already visited rows, whereas UNION ALL will run
faster precisely because it does not keep track of the visited rows.
-Ursprüngliche Nachricht-
Von: sqlite-users
Just the same.
-Ursprüngliche Nachricht-
Von: sqlite-users [mailto:sqlite-users-boun...@mailinglists.sqlite.org] Im
Auftrag von Peng Yu
Gesendet: Dienstag, 03. September 2019 22:14
An: SQLite mailing list
Betreff: [EXTERNAL] [sqlite] What concurrency level is of sqlite?
Hi,
In other
There is only IF NOT EXISTS in the CREATE TABLE command. This assumes that you
may want to keep a pre-existing table and the data it contains.
If you don't care about any old table or ist contents, just issue DROP TABLE IF
EXISTS and CREATE TABLE in a single transaction.
-Ursprüngliche
[mailto:sqlite-users-boun...@mailinglists.sqlite.org] Im
Auftrag von Dominique Devienne
Gesendet: Montag, 02. September 2019 13:50
An: SQLite mailing list
Betreff: Re: [sqlite] [EXTERNAL] Re: http://roaringbitmap.org/
On Mon, Sep 2, 2019 at 12:08 PM Hick Gunter wrote:
> Back in 201
For batch loading via script, you should limit the number of values per
statement (SQLite compiles each statement into memory) and per transaction
(SQLite needs to write to disk after a certain number of pages are modified).
For batch loading via program, you can prepare the insert statement
Dimensions are ignored by SQLite. A field defined CHAR(0) can hold any length
(up to the internal limit) of string. SQlite will only store the actual length
of the string plus its contents, no space is wasted.
-Ursprüngliche Nachricht-
Von: sqlite-users
Back in 2011 I implemented a virtual table using the "fastbit" library by John
Wu of the Lawrence Berekely National Laboratory. This allowed selects of the
form
SELECT ... FROM WHERE rowid IN (SELECT rowid FROM
WHERE );
provided that the data had been inserted before by running
INSERT INTO
This is documented behaviour. Use single quotes for literal strings. SQLite
will assume you meant 'literlal' if your write "literal" and there is no column
of that name. There is no need to quote names in SQLite unless the name
contains non-alpha characters.
-Ursprüngliche Nachricht-
Why would you want to do this?
If you require a SELECT to return rows in a certain order, you need to specify
ORDER BY on the SELECT statement. And not rely on ascending insert time or any
other visitation order effect.
Additionally - unless specific precautions are taken - sorted insert
I think you are looking for UNION ALL to avoid creating an ephemeral table to
implement the implied DISTINCT
-Ursprüngliche Nachricht-
Von: sqlite-users [mailto:sqlite-users-boun...@mailinglists.sqlite.org] Im
Auftrag von Peter da Silva
Gesendet: Donnerstag, 22. August 2019 17:28
An:
As already stated, this looks like you have at least one transaction underways.
Your schema change will become visible only after
1) they are committed on ther "writer" connection AND
2) a new transaction is started on the "reader" connection
If your "readers" are failing to reset or finalize
Maybe you are looking for semaphores. These can be tricky to use correctly in
the case of cooperating processes, where you have to handle the case of the
current owner of the semaphore terminating within the monitored section of code.
-Ursprüngliche Nachricht-
Von: sqlite-users
Reminds me of "... two mice ran up the clock, the clock struck one, and the
other escaped with minor injuries"
-Ursprüngliche Nachricht-
Von: sqlite-users [mailto:sqlite-users-boun...@mailinglists.sqlite.org] Im
Auftrag von Kevin Benson
Gesendet: Donnerstag, 15. August 2019 20:40
An:
How about
#define is_true(tf) ((uintptr_t)0 != (uintptr_t)(tf))
-Ursprüngliche Nachricht-
Von: sqlite-users [mailto:sqlite-users-boun...@mailinglists.sqlite.org] Im
Auftrag von Don V Nielsen
Gesendet: Dienstag, 13. August 2019 22:42
An: SQLite mailing list
Betreff: [EXTERNAL] Re:
But surely any compiler worth ist salt would optimize away all of that code and
just use the result of the expression given as argument in the call ;)
-Ursprüngliche Nachricht-
Von: sqlite-users [mailto:sqlite-users-boun...@mailinglists.sqlite.org] Im
Auftrag von James K. Lowden
i which multiple
modules are then built on top of, it doesn't know which columns are
large/expensive, so the idea was just to use call sqlite3_vtab_nochange for all
of them, which includes the primary key.
> On 13 Aug 2019, at 13:00, Hick Gunter wrote:
>
> Very strange and AFAICT not docu
Nachricht-
Von: sqlite-users [mailto:sqlite-users-boun...@mailinglists.sqlite.org] Im
Auftrag von Kevin Martin
Gesendet: Dienstag, 13. August 2019 13:23
An: SQLite mailing list
Betreff: Re: [sqlite] [EXTERNAL] Correct use of
sqlite3_vtab_nochange/sqlite3_value_nochange
> On 12 Aug 2019, a
I don't think so.
Async IO module creates a queue of pages that will be written to the database
file on disk according to available IO bandwidth.
WAL mode creats a queue of pages from committed transactions that are written
to the database file on disk according to available IO bandwidth.
So how do you propose to have consistency and isolation if SELECT does not
create an automatic transaction if no explicit transaction exists?
Consider:
SELECT FROM ;
BEGIN;
UPDATE SET field = +1;
COMMIT;
If the SELECT and UPDATE statements are not part of the same transaction, there
is no
Works as intended.
"our code base does not use transactions at all" does NOT mean that there are
no transactions, just that SQLite uses *implicit* transactions, i.e. every
statement is in it's own transaction.
"we can share a connection between threads as long as we don't read/write into
the
To correctly determine what SQLite is asking of your xUpdate routine requires
looking at argc, argv[0] and possibly argv[1] (if argc > 1).
You did not state your argc and argv[0] values, so looking at the documentation
would suggest that SQLite is actually asking for an INSERT into a WITHOUT
I see two subproblems in this query
a) estimating total electricity consumption for points in time that do not have
an entry
b) generating regular points in time
ad a) assume a linear consumption of power between two measurements
So for a time tx that is between ta and tb with values of pa and
There is no decimal type in SQLite, and you are lucky that they are converted
to string instead of real, because you cannot do proper (implied) decimal
(point) arithmetic with real (ieee binary floating point) values. The rounding
errors intruduced by binary floating point not beeing able to
You need to
.mode insert
SELECT * FROM ;
Repeat for all your tables.
-Ursprüngliche Nachricht-
Von: sqlite-users [mailto:sqlite-users-boun...@mailinglists.sqlite.org] Im
Auftrag von Luca Ferrari
Gesendet: Freitag, 02. August 2019 10:04
An: SQLite
Betreff: [EXTERNAL] [sqlite] mode
The error is due to a full disk. You should not be deleting files associated
with an SQLite db file.
Have you tried running pragma integrity_check(); before the disk actually
becomes full?
Other than corruption of the file, the two candidates are internal
fragmentation (doing lots of INSERT
What is this tbllog table?
-Ursprüngliche Nachricht-
Von: sqlite-users [mailto:sqlite-users-boun...@mailinglists.sqlite.org] Im
Auftrag von bhandari_nikhil
Gesendet: Donnerstag, 01. August 2019 07:39
An: sqlite-users@mailinglists.sqlite.org
Betreff: [EXTERNAL] [sqlite] Error in recover
SQLite stores rows in a compressed format that requires decoding. To access the
nth field, all the fields that come before it need to be decoded. If there is a
large blob stoed in a blob field, any field after that will suffer a
performance penalty (unless, of course, both fields are required).
s the best way to go for me, not for the sqlite
library, that's why I writing to the sqlite library.
Il giorno mar 30 lug 2019 alle ore 15:50 Hick Gunter ha
scritto:
> f) There are exactly 2 documented functions in your code. Did you not
> read their documentation???
>
> See ht
f) There are exactly 2 documented functions in your code. Did you not read
their documentation???
See https://sqlite.org/c3ref/column_blob.html
" After a type conversion, the result of calling sqlite3_column_type() is
undefined, though harmless. Future versions of SQLite may change the
What you are doing is a very bad idea indeed.
a) you are circumventing the intended interface
b) you are breaking encapsulation, because columnMem returns a pointer to an
internal type, which is useless to you, unless you have made public all the
SQLite internals
c) you are assuming that type
.
From: sqlite-users on behalf of
Hick Gunter
Sent: Monday, July 29, 2019 10:53:02 AM
To: 'SQLite mailing list'
Subject: Re: [sqlite] [EXTERNAL] Help with sqlite3TreeViewSelect
Let's go back to your example statement with your join of two tables.
select b,c from tbl0 join tbl1
Let's go back to your example statement with your join of two tables.
select b,c from tbl0 join tbl1 where tbl0.a = tbl1.a and tbl0.a > ?1;
SQLIte should ask the authorizer the following questions:
1) SELECT
2) READ tbl0
3) READ tbl1
4) READ tbl0 field a
5) READ tbl1 field a
6) READ tbl0 field
That strikes me as purely procedural thinking. Does the set of allowed
operations really depend on the order of the requests (which probably depends
on the query plan)? E.g. "you can update this field of this table only if you
read this other field from that other table *first*"?
Note that parsing debug output is not a stable method of analysis (meaning
SQlite Dev can change anything at whim), whereas the authorizer interface is
documented.
Your implicit claim is "not all instances of column reference are reported to
the authorizer, notably those inside a USING
WITH is basically syntactic sugar that allows you to name the result set of a
certain select and refer to it by name, so that select has to appear in the
generated bytecode and also in the query resolution tree.
Guessing what an element of the query resolution tree does would be very much
This assumes that there is some kind of backing store that needs to be created
once (xCreate) but may be conncted to (xConnect) later.
CREATE VIRTUAL TABLE calls the xCreate function (and DROP TABLE will call
xDestroy), whereas queries will call the xConnect function. IIRC connecting to
an
treff: Re: [sqlite] [EXTERNAL] Re: Estimated Costs and Memory DBs
On Wed, Jul 24, 2019 at 10:45 AM Hick Gunter wrote:
> The speed of a virtual table depends on the backing store and software
> used to implement it.
>
[DD] Sure. virtual-tables can also access the disk and do expensive thi
The speed of a virtual table depends on the backing store and software used to
implement it.
We have virtual tables that reference CTree files as well as virtual tables
that reference memory sections here. The advantage is that the VT
implementation can adjust it's answers in the xBestIndex
This cannot be determined programatically.
The query generator stores an OP_Variable opcode when the SQL program needs to
access the contents of an SQL parameter, and keeps track of the highest
parameter number used, which determines the size of the parameter array.
Even if you were to examine
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