Re: Making Vars outer-join aware - Mailing list pgsql-hackers

From Tom Lane
Subject Re: Making Vars outer-join aware
Date
Msg-id 2070642.1659385590@sss.pgh.pa.us
Whole thread Raw
In response to Re: Making Vars outer-join aware  (Zhihong Yu <zyu@yugabyte.com>)
List pgsql-hackers
Zhihong Yu <zyu@yugabyte.com> writes:
> For v3-0003-label-Var-nullability-in-parser.patch :

> +   if (rtindex > 0 && rtindex <= list_length(pstate->p_nullingrels))
> +       relids = (Bitmapset *) list_nth(pstate->p_nullingrels, rtindex - 1);
> +   else
> +       relids = NULL;
> +
> +   /*
> +    * Merge with any already-declared nulling rels.  (Typically there won't
> +    * be any, but let's get it right if there are.)
> +    */
> +   if (relids != NULL)

> It seems the last if block can be merged into the previous if block. That
> way `relids = NULL` can be omitted.

No, because the list entry we fetch could be NULL.

            regards, tom lane



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