[jira] [Resolved] (PHOENIX-1645) Wrong execution plan generated for indexed query which leads to slow performance

["Mujtaba Chohan (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/PHOENIX-1645?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Mujtaba Chohan resolved PHOENIX-1645.
-------------------------------------
       Resolution: Invalid
    Fix Version/s: 4.3

[~jamestaylor] Using hint for idx4 /*+ INDEX(INDEXED_TABLE idx4) */ uses idx4 correctly. So take away is that since join back to base table is now possible, query plan is correctly using idx1 since it is the first hint in the original query but since it's user override it is as expected. Closing this JIRA as it is behaving as expected in 4.3.

> Wrong execution plan generated for indexed query which leads to slow performance
> --------------------------------------------------------------------------------
>
>                 Key: PHOENIX-1645
>                 URL: https://issues.apache.org/jira/browse/PHOENIX-1645
>             Project: Phoenix
>          Issue Type: Bug
>    Affects Versions: 4.3
>            Reporter: Mujtaba Chohan
>            Assignee: James Taylor
>             Fix For: 4.3
>
>
> Query: select /*+ INDEX(INDEXED_TABLE idx1 idx2 idx3 idx4) */ count(core) from INDEXED_TABLE where core < 10 and db < 200
> Optimal explain plan generated in Phoenix v4.2: 1-CHUNK PARALLEL 1-WAY RANGE SCAN OVER IDX4 [*] - [10]
>     SERVER FILTER BY TO_LONG(DB) < 200
>     SERVER AGGREGATE INTO SINGLE ROW
> *Wrong plan generated in 4.3 that uses skip scan join to base table. Performance of this plan compared to v4.2 is close to 20X slower with 2M rows data*: CLIENT 28-CHUNK PARALLEL 1-WAY FULL SCAN OVER INDEXED_TABLE
>     SERVER FILTER BY USAGE.DB < 200
>     SERVER AGGREGATE INTO SINGLE ROW
>     SKIP-SCAN-JOIN TABLE 0
>         CLIENT 1-CHUNK PARALLEL 1-WAY RANGE SCAN OVER IDX1 [*] - [10]
>             SERVER FILTER BY FIRST KEY ONLY
>     DYNAMIC SERVER FILTER BY ("HOST", "DOMAIN", "FEATURE", "DATE") IN (($22.$24, $22.$25, $22.$26, $22.$27))
>  
> DDL: CREATE TABLE $TABLE (HOST CHAR(2) NOT NULL,DOMAIN VARCHAR NOT NULL,FEATURE VARCHAR NOT NULL,DATE DATE NOT NULL,USAGE.CORE BIGINT,USAGE.DB BIGINT,STATS.ACTIVE_VISITOR INTEGER CONSTRAINT PK PRIMARY KEY (HOST, DOMAIN, FEATURE, DATE)) IMMUTABLE_ROWS=true,MAX_FILESIZE=30485760;CREATE INDEX idx1 ON $TABLE (CORE);CREATE INDEX idx2 ON $TABLE (DB);CREATE INDEX idx3 ON $TABLE (DB,ACTIVE_VISITOR);CREATE INDEX idx4 ON $TABLE (CORE,DB,ACTIVE_VISITOR);CREATE INDEX ids1 ON $TABLE (CORE) SALT_BUCKETS=16;CREATE INDEX ids2 ON $TABLE (DB) SALT_BUCKETS=16;CREATE INDEX ids3 ON $TABLE (DB,ACTIVE_VISITOR) SALT_BUCKETS=16;CREATE INDEX ids4 ON $TABLE (CORE,DB,ACTIVE_VISITOR) SALT_BUCKETS=16;
> Also see perf. run at: http://phoenix-bin.github.io/client/performance/phoenix-20150206042353.htm



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)