From: Tom Lane <tgl@sss.pgh.pa.us>
To: Stephen Frost <sfrost@snowman.net>
Cc: Peter Eisentraut <peter.eisentraut@2ndquadrant.com>
Cc: pgsql-hackers <pgsql-hackers@postgresql.org>
Subject: Re: pg_dump test instability
Date: Mon, 27 Aug 2018 10:45:58 -0400
Message-ID: <1665.1535381158@sss.pgh.pa.us> (raw)
In-Reply-To: <20180827144138.GO3326@tamriel.snowman.net>
References: <5137fe12-d0a2-4971-61b6-eb4e7e8875f8@2ndquadrant.com>
<32399.1535379095@sss.pgh.pa.us>
<20180827144138.GO3326@tamriel.snowman.net>
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
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To: pgsql-hackers@postgresql.org
Cc: tgl@sss.pgh.pa.us, sfrost@snowman.net, peter.eisentraut@2ndquadrant.com
Subject: Re: pg_dump test instability
In-Reply-To: <1665.1535381158@sss.pgh.pa.us>
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