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: Dean Rasheed <dean.a.rasheed@gmail.com>
Cc: Tomas Vondra <tomas.vondra@enterprisedb.com>, pgsql-hackers@postgresql.org
Date: 2021-03-05T00:43:35Z
Lists: pgsql-hackers

Attachments

On Mon, Jan 04, 2021 at 09:45:24AM -0600, Justin Pryzby wrote:
> On Mon, Jan 04, 2021 at 03:34:08PM +0000, Dean Rasheed wrote:
> > * I'm not sure I understand the need for 0001. Wasn't there an earlier
> > version of this patch that just did it by re-populating the type
> > array, but which still had it as an array rather than turning it into
> > a list? Making it a list falsifies some of the comments and
> > function/variable name choices in that file.
> 
> This part is from me.
> 
> I can review the names if it's desired , but it'd be fine to fall back to the
> earlier patch.  I thought a pglist was cleaner, but it's not needed.

This updates the preliminary patches to address the issues Dean raised.

One advantage of using a pglist is that we can free it by calling
list_free_deep(Typ), rather than looping to free each of its elements.
But maybe for bootstrap.c it doesn't matter, and we can just write:
| Typ = NULL; /* Leak the old Typ array */

-- 
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