Re: Memory consumed by child SpecialJoinInfo in partitionwise join planning

Ashutosh Bapat <ashutosh.bapat.oss@gmail.com>

From: Ashutosh Bapat <ashutosh.bapat.oss@gmail.com>
To: Amit Langote <amitlangote09@gmail.com>
Cc: Richard Guo <guofenglinux@gmail.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2023-10-03T13:12:28Z
Lists: pgsql-hackers

Attachments

On Fri, Sep 29, 2023 at 8:36 AM Amit Langote <amitlangote09@gmail.com> wrote:
> IOW, something
> like the following would have sufficed:
>
> @@ -1735,6 +1735,10 @@ build_child_join_sjinfo(PlannerInfo *root,
> SpecialJoinInfo *parent_sjinfo,
>  /*
>   * free_child_sjinfo_members
>   *     Free memory consumed by members of a child SpecialJoinInfo.
> + *
> + * Only members that are translated copies of their counterpart in the parent
> + * SpecialJoinInfo are freed here.  However, members that could be referenced
> + * elsewhere are not freed.
>   */
>  static void
>  free_child_sjinfo_members(SpecialJoinInfo *child_sjinfo)
> @@ -1755,10 +1759,7 @@ free_child_sjinfo_members(SpecialJoinInfo *child_sjinfo)
>     bms_free(child_sjinfo->syn_lefthand);
>     bms_free(child_sjinfo->syn_righthand);
>
> -   /*
> -    * But the list of operator OIDs and the list of expressions may be
> -    * referenced somewhere else. Do not free those.
> -    */
> +   /* semi_rhs_exprs may be referenced, so don't free. */
>  }

Works for me. PFA patchset with these changes. I have still left the
changes addressing your comments as a separate patch for easier
review.

-- 
Best Wishes,
Ashutosh Bapat

Commits

  1. Code review for 6190d828cd2

  2. Do not translate dummy SpecialJoinInfos for child joins

  3. Reduce memory used by partitionwise joins

  4. Remove dummy_spinlock