Heed lock protocol in DROP OWNED BY
authorAlvaro Herrera <alvherre@alvh.no-ip.org>
Wed, 6 May 2020 16:29:41 +0000 (12:29 -0400)
committerAlvaro Herrera <alvherre@alvh.no-ip.org>
Wed, 6 May 2020 16:29:41 +0000 (12:29 -0400)
commit59273a7cec34e5bb8a9483f23a03e3318b52d65b
tree0e948af67f31229e32d30a84b6790f1af785ce88
parent984aca448d5dba0f1be162ce41aa23becf5e931a
Heed lock protocol in DROP OWNED BY

We were acquiring object locks then deleting objects one by one, instead
of acquiring all object locks first, ignoring those that did not exist,
and then deleting all objects together.   The latter is the correct
protocol to use, and what this commits changes to code to do.  Failing
to follow that leads to "cache lookup failed for relation XYZ" error
reports when DROP OWNED runs concurrently with other DDL -- for example,
a session termination that removes some temp tables.

Author: Álvaro Herrera
Reported-by: Mithun Chicklore Yogendra (Mithun CY)
Reviewed-by: Ahsan Hadi, Tom Lane
Discussion: https://postgr.es/m/CADq3xVZTbzK4ZLKq+dn_vB4QafXXbmMgDP3trY-GuLnib2Ai1w@mail.gmail.com
src/backend/catalog/dependency.c
src/backend/catalog/pg_shdepend.c
src/backend/commands/subscriptioncmds.c
src/include/catalog/dependency.h