Horton

Re: POC: converting Lists into arrays

Tom Lane <tgl@sss.pgh.pa.us>

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From: Tom Lane <tgl@sss.pgh.pa.us>
To: Robert Haas <robertmhaas@gmail.com>
Cc: David Steele <david@pgmasters.net>, David Rowley <david.rowley@2ndquadrant.com>, Jesper Pedersen <jesper.pedersen@redhat.com>, Andres Freund <andres@anarazel.de>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2019-07-16T16:08:53Z
Lists: pgsql-hackers 
Robert Haas <robertmhaas@gmail.com> writes:
> On Tue, Jul 16, 2019 at 10:44 AM Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> OK, I'm outvoted, will do it that way.

> I cast my vote in the other direction i.e. for sticking with qsort.

Didn't see this until after pushing a commit that uses "list_sort".

While composing that commit message another argument occurred to me,
which is that renaming makes it absolutely sure that any external
callers will notice they have an API change to deal with, no matter
how forgiving their compiler is.  Also, if somebody really really
doesn't want to cope with the change, they can now make their own
version of list_qsort (stealing it out of 1cff1b95a) and the core
code won't pose a conflict.

So I'm good with "list_sort" at this point.

			regards, tom lane

Commits

  1. Remove EState.es_range_table_array.

  2. Rationalize use of list_concat + list_copy combinations.

  3. Cosmetic improvements in setup of planner's per-RTE arrays.

  4. Make better use of the new List implementation in a couple of places

  5. Fix sepgsql test results for commit d97b714a2.

  6. Avoid using lcons and list_delete_first where it's easy to do so.

  7. Remove lappend_cell...() family of List functions.

  8. Clean up some ad-hoc code for sorting and de-duplicating Lists.

  9. Redesign the API for list sorting (list_qsort becomes list_sort).

  10. Remove dead code.

  11. Represent Lists as expansible arrays, not chains of cons-cells.

  12. Standardize some more loops that chase down parallel lists.

  13. Reimplement the linked list data structure used throughout the backend.