Re: when do I analyze after concurrent index creation?
| От | Tom Lane |
|---|---|
| Тема | Re: when do I analyze after concurrent index creation? |
| Дата | |
| Msg-id | 8902.1382110970@sss.pgh.pa.us обсуждение исходный текст |
| Ответ на | Re: when do I analyze after concurrent index creation? (dinesh kumar <dineshkumar02@gmail.com>) |
| Ответы |
Re: when do I analyze after concurrent index creation?
Re: when do I analyze after concurrent index creation? |
| Список | pgsql-general |
dinesh kumar <dineshkumar02@gmail.com> writes:
> When we create an index, i believe the postgres engine it self update it's
> catalog about the index availability.
ANALYZE normally collects statistics about the contents of table columns.
Thus, adding (or removing) an index does not create any reason to
re-ANALYZE.
However ... if you have an index on an expression (not just a simple
column value), that cues ANALYZE to collect statistics about the values of
that expression. So re-analyzing is useful after creating such an index,
to give the planner a better idea of when to use that index.
Whether you used CREATE INDEX CONCURRENTLY or some other way of creating
the index doesn't matter at all.
regards, tom lane
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