Re: [HACKERS] Concurrent VACUUM: first results

> "Hiroshi Inoue" <Inoue(at)tpf(dot)co(dot)jp> writes:
> > CommitTransactionCommand() is executed at the end of vc_getrels()
> > and vc_delhilowstats() is executed without StartTransactionCommand().
>
> Oooh, good eye! I wonder how long that bug's been there?
>
> I'm still inclined to remove that call to vc_delhilowstats, because it
> seems like a global delete of statistics can't help but be a problem.
> But if we keep it, you're dead right: it has to be inside a transaction.
>

With the new pg_statistic cache, you can efficiently do a heap_insert or
heap_replace dending on whether an entry already exists. In the old
code, that was hard because you had to scan entire table looking for a
match so I just did a delete, and they I knew to do an insert.

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