Re: [HACKERS] pgbench vs. SERIALIZABLE

2013-05-21 Thread Josh Berkus
Presumably we would want to repeat all of the ordinary commands, in the file, but not any of the backslash set commands that precede any ordinary commands. But what if backslash set commands are sprinkled between ordinary commands? See, this is why I had no intention of retrying. Since

Re: [HACKERS] pgbench vs. SERIALIZABLE

2013-05-20 Thread Kevin Grittner
Josh Berkus j...@agliodbs.com wrote: I recently had a reason to benchmark a database which is default SERIALIZABLE mode.  I was startled to discover that pgbench is set up to abort the client once it hits a serialization failure.  You get a bunch of these: Client 7 aborted in state 11:

Re: [HACKERS] pgbench vs. SERIALIZABLE

2013-05-20 Thread Heikki Linnakangas
On 20.05.2013 14:50, Kevin Grittner wrote: I raised this issue near the end of SSI development, but nobody seemed very interested and someone argued that a tool to do that would be good but we shouldn't try to do it in pgbench -- so I let it drop at the time. +1 on doing it in pgbench. -

Re: [HACKERS] pgbench vs. SERIALIZABLE

2013-05-20 Thread Jeff Janes
On Mon, May 20, 2013 at 4:50 AM, Kevin Grittner kgri...@ymail.com wrote: I raised this issue near the end of SSI development, but nobody seemed very interested and someone argued that a tool to do that would be good but we shouldn't try to do it in pgbench -- so I let it drop at the time.

Re: [HACKERS] pgbench vs. SERIALIZABLE

2013-05-20 Thread Fabien COELHO
I think it would be good to do it in pgbench, provided it can be done fairly cleanly. Presumably we would want to repeat all of the ordinary commands, in the file, but not any of the backslash set commands that precede any ordinary commands. But what if backslash set commands are sprinkled

Re: [HACKERS] pgbench vs. SERIALIZABLE

2013-05-19 Thread Fabien COELHO
Should it give up trying under some conditions, say there are more errors than transactions? I don't really see the point of that. I can't think of a scenario where you would get too many serialization errors to even finish the pgbench test. My point is really to avoid in principle a

[HACKERS] pgbench vs. SERIALIZABLE

2013-05-18 Thread Josh Berkus
Hackers, I recently had a reason to benchmark a database which is default SERIALIZABLE mode. I was startled to discover that pgbench is set up to abort the client once it hits a serialization failure. You get a bunch of these: Client 7 aborted in state 11: ERROR: could not serialize access

Re: [HACKERS] pgbench vs. SERIALIZABLE

2013-05-18 Thread Fabien COELHO
My thinking is that what pgbench should do is: * track an error count * if it finds an error, don't increment the transaction count, but do increment the error count. * then continue to the next transaction. Does that seem like the right approach? Could it retry the *same* transaction

Re: [HACKERS] pgbench vs. SERIALIZABLE

2013-05-18 Thread Marko Tiikkaja
On 2013-05-19 00:03, Fabien COELHO wrote: My thinking is that what pgbench should do is: * track an error count * if it finds an error, don't increment the transaction count, but do increment the error count. * then continue to the next transaction. Does that seem like the right approach?