On Tue, Sep 01, 2020 at 05:08:25PM -0400, Alvaro Herrera wrote: > +1 on fixing this, since the ability to change stats target is new in > pg13. > > On 2020-Aug-31, Justin Pryzby wrote: > > > Maybe it should have a comma, like ", STATISTICS %s"? > > It does need some separator. Maybe a comma is sufficient, but I'm not > sure: that will fail when we add cross-relation stats, because the > FROM clause will have more relations and possibly have commas too.
Good thought. You said it'll "fail", but I guess you mean it could be confusing to look at. I didn't actually know that "multiple tables" were planned for MV stats. Another consideration is expression stats (as compared with expression indexes). I don't see how that helps guide this decision at all, though. I think trying to parse \d output is discouraged and a bad idea, but it's obviously not ok if the output is ambiguous. But it's not ambiguous, since STATISTICS is capitalized and unquoted. Arguably, "nn" could be construed as looking like a table alias, which doesn't make sense here, and integer aliases would also need to be quoted (and seem unlikely and not useful). ... FROM t1, t2, STATISTICS nn I think this is 1) unambiguous; 2) clear; 3) consistent with other output and with the "ALTER STATISTICS SET STATISTICS NN" command. It could say "SET" but I don't think it's useful to include; 4) seems to reasonably anticipate future support for expressions and multiple tables; I'm happy if someone suggests something better, but I don't know what that would be. Unless we hurried up and finished this for v13, and included stxstattarget. https://commitfest.postgresql.org/29/2692/ https://www.postgresql.org/message-id/flat/c0939aba-3b12-b596-dd08-913dda4b40f0%40nttcom.co.jp_1#32680b2fe0ab473c58a33eb0f9f00d42 Maybe it's not relevant, but I found these don't have a separator. ppendPQExpBufferStr(&buf, " DEFERRABLE"); ppendPQExpBufferStr(&buf, " INITIALLY DEFERRED"); ppendPQExpBufferStr(&buf, " INVALID"); ppendPQExpBufferStr(&buf, " PRIMARY KEY,"); ppendPQExpBufferStr(&buf, " REPLICA IDENTITY"); ppendPQExpBufferStr(&buf, " UNIQUE,"); ppendPQExpBufferStr(&buf, " UNIQUE CONSTRAINT,"); ppendPQExpBufferStr(&buf, " CLUSTER"); ppendPQExpBufferStr(&buf, " AS RESTRICTIVE"); ppendPQExpBuffer(&buf, "\n TO %s", These look like the only similar things with more than a single separator: ppendPQExpBuffer(&buf, "\n USING (%s)", ppendPQExpBuffer(&buf, "\n WITH CHECK (%s)", -- Justin
