Re: [HACKERS] Parallel worker error - Mailing list pgsql-hackers

From Tom Lane
Subject Re: [HACKERS] Parallel worker error
Date
Msg-id 24985.1504094667@sss.pgh.pa.us
Whole thread Raw
In response to Re: [HACKERS] Parallel worker error  (Amit Kapila <amit.kapila16@gmail.com>)
Responses Re: [HACKERS] Parallel worker error  (Robert Haas <robertmhaas@gmail.com>)
List pgsql-hackers
Amit Kapila <amit.kapila16@gmail.com> writes:
> I am able to reproduce this without involving session authorization
> guc as well.  One needs to drop the newly created role from another
> session, then also we can see the same error.

Hm.  I suspect the basic shape of what's happening here is "an existing
session can continue to run with OuterUserId corresponding to a dropped
role, but we fail when trying to duplicate that state into a parallel
worker".  I wonder whether there aren't similar gotchas for other GUCs
whose interpretation depends on catalog lookups, eg search_path.

We might need to redesign the GUC-propagation mechanism so it sends
the various internal representations of GUC values, not the user-visible
strings.  (I'm thinking of the blobs that guc.c can use to restore a
previous state at transaction abort ... don't recall what the code
calls them ATM.)
        regards, tom lane



pgsql-hackers by date:

Previous
From: Amit Khandekar
Date:
Subject: Re: [HACKERS] Parallel Append implementation
Next
From: Antonin Houska
Date:
Subject: Re: [HACKERS] WIP: Separate log file for extension