Re: Speedup twophase transactions

On Fri, Apr 1, 2016 at 10:53 PM, Stas Kelvich <s(dot)kelvich(at)postgrespro(dot)ru> wrote:
> I wrote:
>> While testing the patch, I found a bug in the recovery conflict code
>> path. You can do the following to reproduce it:
>> 1) Start a master with a standby
>> 2) prepare a transaction on master
>> 3) Stop immediate on standby to force replay
>> 4) commit prepare transaction on master
>> 5) When starting the standby, it remains stuck here:
>
> Hm, I wasn’t able to reproduce that. Do you mean following scenario or am I missing something?
>
> (async replication)
>
> $node_master->psql('postgres', "
> begin;
> insert into t values (1);
> prepare transaction 'x';
> ");
> $node_slave->teardown_node;
> $node_master->psql('postgres',"commit prepared 'x'");
> $node_slave->start;
> $node_slave->psql('postgres',"select count(*) from pg_prepared_xacts", stdout => \$psql_out);
> is($psql_out, '0', "Commit prepared on master while slave is down.");

Actually, not exactly, the transaction prepared on master created a
table. Sorry for the lack of precisions in my review.
--
Michael