Re: Index no longer being used, destroying and recreating it restores use.

Koen De Groote <kdg.dev@gmail.com> writes:
> I've got a table with about 30 million rows and a particular index that up
> until recently was actively being used.
> And then it stopped being used and the query that the index was made for,
> is now doing sequential scans.
> Deleting the index and creating it again, seems to fix the problem. The new
> index, which is identical in composition, is being used and the query in
> question no longer uses sequential scans.

It's possible that the index had bloated to the point where the planner
thought it was cheaper to use a seqscan.  Did you make a note of the
cost estimates for the different plans?

            regards, tom lane