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Am 30.05.2017 um 10:42 schrieb
Wetzel, Juergen (Juergen):
> I have a question concerning the query planner. I observe that chosen query plan differs on length and content of a like > search _expression_. We have a view combining data from two tables, both containing same number of rows (round about 30000). > Used PostgreSQL version is 9.3.15 on Windows. DDL of tables and view see below. the query is on DOCUMENTDATA, but plan and DDL for c3k_documentdata and other tables. > Only 130 rows out of the 30000 have ARCHIVED = 0 in this case i would suggest a partial index: create index <indexname> on <tablename> (archived) where archived = 0; You can also increase the statistics for the columns subject and mailContent ALTER TABLE <tablename>
ALTER COLUMN <column_name> SET STATISTICS
= 1000;
(as example, the default-value is 100) Regards, Andreas -- 2ndQuadrant - The PostgreSQL Support Company. www.2ndQuadrant.com |
