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https://issues.apache.org/jira/browse/PHOENIX-914?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14152545#comment-14152545
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Jeffrey Zhong commented on PHOENIX-914:
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The hbase row key timestamp are always there for each KV so we could expose it
as a pseudo column and it won't cause anything. Even if you want to use it
after the table schema is created or any old Phoenix tables without any change.
{quote}
Defining as a real column that is part of the row key
{quote}
Are you suggesting the same time stamp values are duplicated in row for one KV?
A hbase kv's key portion always has row
key/columnfamily/columnqualifier/timestamp. If we use the example in the JIRA
with a little bit modified primary key as (METRICID, SERVICENAME, ORIGIN,
APPID, TIME, IPID), will the same TIME value duplicated for all KVs of one row?
Thanks.
> Native HBase timestamp support to optimize date range queries in Phoenix
> -------------------------------------------------------------------------
>
> Key: PHOENIX-914
> URL: https://issues.apache.org/jira/browse/PHOENIX-914
> Project: Phoenix
> Issue Type: Improvement
> Affects Versions: 4.0.0
> Reporter: Vladimir Rodionov
> Assignee: Vladimir Rodionov
>
> For many applications one of the column of a table can be (and must be)
> naturally mapped
> to HBase timestamp. What it gives us is the optimization on StoreScanner
> where HFiles with timestamps out of range of
> a Scan operator will be omitted. Let us say that we have time-series type of
> data (EVENTS) and custom compaction, where we create
> series of HFiles with continuous non-overlapping timestamp ranges.
> CREATE TABLE IF NOT EXISTS ODS.EVENTS (
> METRICID VARCHAR NOT NULL,
> METRICNAME VARCHAR,
> SERVICENAME VARCHAR NOT NULL,
> ORIGIN VARCHAR NOT NULL,
> APPID VARCHAR,
> IPID VARCHAR,
> NVALUE DOUBLE,
> TIME TIMESTAMP NOT NULL /+ TIMESTAMP +/,
> DATA VARCHAR,
> SVALUE VARCHAR
> CONSTRAINT PK PRIMARY KEY (METRICID, SERVICENAME, ORIGIN, APPID, IPID,
> TIME)
> ) SALT_BUCKETS=40, IMMUTABLE_ROWS=true,VERSIONS=1,DATA_BLOCK_ENCODING='NONE';
> Make note on TIME TIMESTAMP NOT NULL /+ TIMESTAMP +/ - this is the Hint to
> Phoenix that the column
> TIME must be mapped to HBase timestamp.
> The Query:
> Select all events of type 'X' for last 7 days
> SELECT * from EVENTS WHERE METRICID = 'X' and TIME < NOW() and TIME > NOW() -
> 7*24*3600000; (this may be not correct SQL syntax of course)
> These types of queries will be efficiently optimized if:
> 1. Phoenix maps TIME column to HBase timestamp
> 2. Phoenix smart enough to map WHERE clause on TIME attribute to Scan
> timerange
> Although this :
> Properties props = new Properties();
> props.setProperty(PhoenixRuntime.CURRENT_SCN_ATTRIB, Long.toString(ts));
> Connection conn = DriverManager.connect(myUrl, props);
> conn.createStatement().execute("UPSERT INTO myTable VALUES ('a')");
> conn.commit();
> will work in my case- it may not be efficient from performance point of view
> because for every INSERT/UPSERT
> new Connection object and new Statement is created, beside this we still need
> the optimization 2. (see above).
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