> On 20 Mar 2017, at 16:39, Craig Ringer <cr...@2ndquadrant.com> wrote: > > On 20 March 2017 at 20:57, Stas Kelvich <s.kelv...@postgrespro.ru> wrote: >> >>> On 20 Mar 2017, at 15:17, Craig Ringer <cr...@2ndquadrant.com> wrote: >>> >>>> I thought about having special field (or reusing one of the existing >>>> fields) >>>> in snapshot struct to force filtering xmax > snap->xmax or xmin = >>>> snap->xmin >>>> as Petr suggested. Then this logic can reside in ReorderBufferCommit(). >>>> However this is not solving problem with catcache, so I'm looking into it >>>> right now. >>> >>> OK, so this is only an issue if we have xacts that change the schema >>> of tables and also insert/update/delete to their heaps. Right? >>> >>> So, given that this is CF3 for Pg10, should we take a step back and >>> impose the limitation that we can decode 2PC with schema changes or >>> data row changes, but not both? >> >> Yep, time is tight. I’ll try today/tomorrow to proceed with this two scan >> approach. >> If I’ll fail to do that during this time then I’ll just update this patch to >> decode >> only non-ddl 2pc transactions as you suggested. > > I wasn't suggesting not decoding them, but giving the plugin the > option of whether to proceed with decoding or not. > > As Simon said, have a pre-decode-prepared callback that lets the > plugin get a lock on the 2pc xact if it wants, or say it doesn't want > to decode it until it commits. > > That'd be useful anyway, so we can filter and only do decoding at > prepare transaction time of xacts the downstream wants to know about > before they commit.
Ah, got that. Okay. > -- > Craig Ringer http://www.2ndQuadrant.com/ > PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
