Re: pg_dump test instability

Tom Lane <tgl@sss.pgh.pa.us>

From: Tom Lane <tgl@sss.pgh.pa.us>
To: Stephen Frost <sfrost@snowman.net>
Cc: Peter Eisentraut <peter.eisentraut@2ndquadrant.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2018-08-27T14:45:58Z
Lists: pgsql-hackers
Stephen Frost <sfrost@snowman.net> writes:
> * Tom Lane (tgl@sss.pgh.pa.us) wrote:
>> However, at least for the directory-format case (which I think is the
>> only one supported for parallel restore), we could make it compare the
>> file sizes of the TABLE DATA items.  That'd work pretty well as a proxy
>> for both the amount of effort needed for table restore, and the amount
>> of effort needed to build indexes on the tables afterwards.

> Parallel restore also works w/ custom-format dumps.

Really.  Well then the existing code is even more broken, because it
only does this sorting for directory output:

	/* If we do a parallel dump, we want the largest tables to go first */
	if (archiveFormat == archDirectory && numWorkers > 1)
		sortDataAndIndexObjectsBySize(dobjs, numObjs);

so that parallel restore is completely left in the lurch with a
custom-format dump.

But I imagine we can get some measure of table data size out of a custom
dump too.

			regards, tom lane


Commits

  1. Improve parallel scheduling logic in pg_dump/pg_restore.