2017-04-22 11:30 GMT+02:00 Simon Riggs <si...@2ndquadrant.com>: > On 21 April 2017 at 01:21, Tomas Vondra <tomas.von...@2ndquadrant.com> > wrote: > > On 04/21/2017 12:13 AM, Tom Lane wrote: > >> > >> Alvaro Herrera <alvhe...@2ndquadrant.com> writes: > >>> > >>> Simon just pointed out that having the WITH clause appear in the middle > >>> of the CREATE STATISTICS command looks odd; apparently somebody else > >>> already complained on list about the same. Other commands put the WITH > >>> clause at the end, so perhaps we should do likewise in the new command. > >> > >> > >>> Here's a patch to implement that. I verified that if I change > >>> qualified_name to qualified_name_list, bison does not complain about > >>> conflicts, so this new syntax should support extension to multiple > >>> relations without a problem. > >> > >> > >> Yeah, WITH is fully reserved, so as long as the clause looks like > >> WITH ( stuff... ) you're pretty much gonna be able to drop it > >> wherever you want. > >> > >>> Discuss. > >> > >> > >> +1 for WITH at the end; the existing syntax looks weird to me too. > >> > > > > -1 from me > > > > I like the current syntax more, and WHERE ... WITH seems a bit weird to > me. > > But more importantly, one thing Dean probably considered when proposing > the > > current syntax was that we may add support for partial statistics, pretty > > much like partial indexes. And we don't allow WITH at the end (after > WHERE) > > for indexes: > > > > test=# create index on t (a) where a < 100 with (fillfactor=10); > > ERROR: syntax error at or near "with" > > LINE 1: create index on t (a) where a < 100 with (fillfactor=10); > > ^ > > test=# create index on t (a) with (fillfactor=10) where a < 100; > > OK, didn't know about WHERE clause; makes sense. > > Currently WITH is supported in two places, which feels definitely > wrong. The WITH clause is used elsewhere to provide optional > parameters, and if there are none present it is optional. > > OK, so lets try... > > 1. > No keyword at all, just list of statistics we store (i.e. just lose the > WITH) > CREATE STATISTICS s1 (dependencies, ndistinct) ON (a, b) FROM t1 WHERE > partial-stuff; > > and if there are options, use the WITH for the optional parameters like > this > CREATE STATISTICS s1 (dependencies, ndistinct) WITH (options) ON (a, > b) FROM t1 WHERE partial-stuff; > > 2. > USING keyword, no brackets > CREATE STATISTICS s1 USING (dependencies, ndistinct) ON (a, b) FROM t1 > WHERE partial-stuff; > > and if there are options, use the WITH for the optional parameters like > this > CREATE STATISTICS s1 USING (dependencies, ndistinct) WITH (options) ON > (a, b) FROM t1 WHERE partial-stuff; > > > I think I like (2) >
+1 Regards Pavel > > -- > Simon Riggs http://www.2ndQuadrant.com/ > PostgreSQL Development, 24x7 Support, Remote DBA, 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 >
