Re: [HACKERS] Hot standby, running xacts, subtransactions

2009-03-03 Thread Simon Riggs
On Mon, 2009-03-02 at 21:11 -0500, Robert Treat wrote: On Wednesday 25 February 2009 16:43:54 Simon Riggs wrote: On Wed, 2009-02-25 at 13:33 -0800, Josh Berkus wrote: You raised that as an annoyance previously because it means that connection in hot standby mode may be delayed in cases

Re: [HACKERS] Hot standby, running xacts, subtransactions

2009-03-03 Thread Robert Treat
On Tuesday 03 March 2009 03:22:30 Simon Riggs wrote: On Mon, 2009-03-02 at 21:11 -0500, Robert Treat wrote: On Wednesday 25 February 2009 16:43:54 Simon Riggs wrote: On Wed, 2009-02-25 at 13:33 -0800, Josh Berkus wrote: You raised that as an annoyance previously because it means that

Re: [HACKERS] Hot standby, running xacts, subtransactions

2009-03-02 Thread Robert Treat
On Wednesday 25 February 2009 16:43:54 Simon Riggs wrote: On Wed, 2009-02-25 at 13:33 -0800, Josh Berkus wrote: You raised that as an annoyance previously because it means that connection in hot standby mode may be delayed in cases of heavy, repeated use of significant numbers of

Re: [HACKERS] Hot standby, running xacts, subtransactions

2009-02-25 Thread Simon Riggs
On Wed, 2009-02-25 at 22:39 +0200, Heikki Linnakangas wrote: When we take the snapshot of running transactions in the master, in GetRunningTransactionData(), it only includes top-level xids and those subxids that are in the subxid caches. Overflowed subxids are not included. Isn't that a

Re: [HACKERS] Hot standby, running xacts, subtransactions

2009-02-25 Thread Heikki Linnakangas
Simon Riggs wrote: On Wed, 2009-02-25 at 22:39 +0200, Heikki Linnakangas wrote: When we take the snapshot of running transactions in the master, in GetRunningTransactionData(), it only includes top-level xids and those subxids that are in the subxid caches. Overflowed subxids are not

Re: [HACKERS] Hot standby, running xacts, subtransactions

2009-02-25 Thread Simon Riggs
On Wed, 2009-02-25 at 23:08 +0200, Heikki Linnakangas wrote: That is exactly the reason why we don't treat an overflowed snapshot as a valid starting point. We don't? I don't see anything stopping it. In GetRunningTransactionData() we explicitly set latestRunningXid to

Re: [HACKERS] Hot standby, running xacts, subtransactions

2009-02-25 Thread Josh Berkus
You raised that as an annoyance previously because it means that connection in hot standby mode may be delayed in cases of heavy, repeated use of significant numbers of subtransactions. While most users still don't use explicit subtransactions at all, wouldn't this also affect users who use

Re: [HACKERS] Hot standby, running xacts, subtransactions

2009-02-25 Thread Simon Riggs
On Wed, 2009-02-25 at 13:33 -0800, Josh Berkus wrote: You raised that as an annoyance previously because it means that connection in hot standby mode may be delayed in cases of heavy, repeated use of significant numbers of subtransactions. While most users still don't use explicit