Istvan Toth created PHOENIX-6797:
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Summary: Optimize rowkey prefix selects for salted tables
Key: PHOENIX-6797
URL: https://issues.apache.org/jira/browse/PHOENIX-6797
Project: Phoenix
Issue Type: Bug
Components: core
Reporter: Istvan Toth
For a salted table with a composite PK, queries using a PK prefix are turned
into basically full scans.
We should scan only the salt key + PK prefix range for each key.
i.e we have the salted table
{noformat}
CREATE TABLE T (ID1 VARCHAR(64) not null, ID2 VARCHAR(15) not null, ID3
VARCHAR(24), V1 DATE,
CONSTRAINT pk PRIMARY KEY (ID1, ID2, ID3)) SALT_BUCKETS = 31;{noformat}
and we do a select based on ID1:
{noformat}
select * from T where id1='whatever';{noformat}
Phoenix will do a range scan over the following, which is basically a full scan.
[0,'whatever'] - [30,'whatever']
However, we only really need to scan the far smaller
{noformat}
[0,'whatever'] - [0,'whateves']
,[1,'whatever'] - [1,'whateves']
..
,[30,'whatever'] - [30,'whateves']{noformat}
ranges.
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