Horton

Re: POC: converting Lists into arrays

Craig Ringer <craig@2ndquadrant.com>

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From: Craig Ringer <craig@2ndquadrant.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Andres Freund <andres@anarazel.de>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2019-08-08T03:36:44Z
Lists: pgsql-hackers 
On Thu, 1 Aug 2019 at 07:40, Tom Lane <tgl@sss.pgh.pa.us> wrote:

> Andres Freund <andres@anarazel.de> writes:
> > Unfortunately foreach(ListCell *lc, ...) doesn't work with the current
> > definition. Which I think isn't great, because the large scopes for loop
> > iteration variables imo makes the code harder to reason about.
>
>
Totally agree.


>
> you can only put one <declaration> into the first element of a
> for (;;).
>

Use an anonymous block outer scope? Or if not permitted even by C99 (which
I think it is), a do {...} while (0);  hack?


-- 
 Craig Ringer                   http://www.2ndQuadrant.com/
 2ndQuadrant - PostgreSQL Solutions for the Enterprise

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.