Hello! > only 1 out of the 16 available cores get spiked to 100%, while the rest remain idle
This is to be expected unless you crank query parallelism up: https://apacheignite.readme.io/docs/sql-performance-and-debugging#query-parallelism Unfortunately, the setting is only available via cache configuration/cache template. Regards, -- Ilya Kasnacheev пт, 30 нояб. 2018 г. в 17:43, yongjec <yong...@gmail.com>: > Here is the explain plan. > > 0: jdbc:ignite:thin://127.0.0.1/> EXPLAIN SELECT DISTINCT ACCOUNT_ID FROM > PERF_POSITIONS; > 'PLAN' > 'SELECT DISTINCT > __Z0.ACCOUNT_ID AS __C0_0 > FROM PUBLIC.PERF_POSITIONS __Z0 > /* PUBLIC."_key_PK" */' > 'SELECT DISTINCT > __C0_0 AS ACCOUNT_ID > FROM PUBLIC.__T0 > /* PUBLIC."merge_scan" */' > 2 rows selected (0.026 seconds) > > > Based on your suggestion, I tested below changes, but none of them made a > difference. In all cases, the query took consistently 56-60 seconds. > > > 1. Having the index with inline size 60. > > CREATE INDEX PERF_POSITIONS_IDX ON PERF_POSITIONS (ACCOUNT_ID) INLINE_SIZE > 60; > > > 2. Re-creating the table with VARCHAR size 4. (all the values in this > particular dataset are 4 chars). > > CREATE TABLE PERF_POSITIONS ( > ACCOUNT_ID VARCHAR(4) NOT NULL, > ... > > > 3. Using index hint. > > SELECT DISTINCT ACCOUNT_ID FROM PERF_POSITIONS USE > INDEX(PERF_POSITIONS_IDX); > > > On a side note, I noticed that while the query is running, only 1 out of > the > 16 available cores get spiked to 100%, while the rest remain idle. Not sure > whether this is expected. > > > > -- > Sent from: http://apache-ignite-users.70518.x6.nabble.com/ >
