Horton

Re: PoC/WIP: Extended statistics on expressions

Justin Pryzby <pryzby@telsasoft.com>

View thread View on postgr.es
From: Justin Pryzby <pryzby@telsasoft.com>
To: Tomas Vondra <tomas.vondra@enterprisedb.com>
Cc: Dean Rasheed <dean.a.rasheed@gmail.com>, pgsql-hackers@postgresql.org
Date: 2021-01-22T04:01:01Z
Lists: pgsql-hackers 
On Fri, Jan 22, 2021 at 04:49:51AM +0100, Tomas Vondra wrote:
> > > | Statistics objects:
> > > |     "public"."s2" (ndistinct, dependencies, mcv) ON  FROM t
> 
> Umm, for me that prints:

>     "public"."s2" ON ((i + 1)), (((i + 1) + 0)) FROM t
> 
> which I think is OK. But maybe there's something else to trigger the
> problem?

Oh.  It's because I was using /usr/bin/psql and not ./src/bin/psql.
I think it's considered ok if old client's \d commands don't work on new
server, but it's not clear to me if it's ok if they misbehave.  It's almost
better it made an ERROR.

In any case, why are there so many parentheses ?

-- 
Justin

Commits

  1. Disallow extended statistics on system columns

  2. Identify simple column references in extended statistics

  3. Don't print extra parens around expressions in extended stats

  4. Change position of field "transformed" in struct CreateStatsStmt.

  5. Add transformed flag to nodes/*funcs.c for CREATE STATISTICS

  6. Stabilize stats_ext test with other collations

  7. Extended statistics on expressions

  8. Reduce duration of stats_ext regression tests

  9. Allow composite types in catalog bootstrap

  10. Convert Typ from array to list in bootstrap

  11. Disallow CREATE STATISTICS on system catalogs