Horton

Re: [DOC] Document concurrent index builds waiting on each other

James Coleman <jtc331@gmail.com>

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From: James Coleman <jtc331@gmail.com>
To: Michael Paquier <michael@paquier.xyz>
Cc: Alvaro Herrera <alvherre@2ndquadrant.com>, Bruce Momjian <bruce@momjian.us>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2020-02-14T21:10:35Z
Lists: pgsql-hackers 
On Sun, Sep 29, 2019 at 9:24 PM Michael Paquier <michael@paquier.xyz> wrote:
>
> On Sat, Sep 28, 2019 at 10:22:28PM -0300, Alvaro Herrera wrote:
> > I always thought that create index concurrently was prevented from
> > running concurrently in a table by the ShareUpdateExclusive lock that's
> > held during the operation.
>
> REINDEX CONCURRENTLY and CIC can deadlock while waiting for each other
> to finish after their validation phase, see:
> https://www.postgresql.org/message-id/20190507030756.GD1499@paquier.xyz
> https://www.postgresql.org/message-id/20190507032543.GH1499@paquier.xyz

Michael,

Thanks for the cross-link. Do you think this would be valuable to
document at the same time? Or did you just want to ensure we were also
aware of this particular downfall? If the latter, I appreciate it,
it's helpful info. If the latter, let me know, and I'll try to update
the patch.

Thanks,
James

Commits

  1. Call out vacuum considerations in create index docs

  2. Document concurrent indexes waiting on each other

  3. snapshot scalability: Don't compute global horizons while building snapshots.

  4. Remove PROC_IN_ANALYZE and derived flags

  5. Improve performance of get_actual_variable_range with recently-dead tuples.