On Wed, Nov 25, 2015 at 9:13 AM, Lukas Fittl <lu...@fittl.com> wrote:
> On Mon, Nov 23, 2015 at 11:53 PM, Peter Geoghegan <p...@heroku.com> wrote: > >> One specific justification he gave for not using pg_stat_statements was: >> >> "Doesn’t merge bind vars in IN()" (See slide #11) >> >> I wonder: >> >> * How do other people feel about this? Personally, I've seen enough >> problems of this kind in the field that "slippery slope" arguments >> against this don't seem very compelling. >> > > As someone who runs a little monitoring service thats solely based on > pg_stat_statements data, ignoring IN list length would certainly be a good > change. > > We currently do this in post-processing, together with other data cleanup > (e.g. ignoring the length of a VALUES list in an INSERT statement). > > Given the fact that pgss data is normalized & you don't know which plan > was chosen, I don't think distinguishing based on the length of the list > helps anyone really. > > I see pg_stat_statements as a high-level overview of which queries have > run, and which ones you might want to look into closer using e.g. > auto_explain. > I still have the plans to try to marry pg_stat_statements and auto_explain for the next iteration of "online query plans" extension I was proposing a few months ago, and the first thing I was going to look into is rectifying this problem with IN() jumbling. So, have a +1 from me. -- Alex
