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

From Zhihong Yu
Subject Re: Making Vars outer-join aware
Date
Msg-id CALNJ-vR4P+He33rEq=TYe7jN79MfCKQnTHN4a538ERvuquworg@mail.gmail.com
Whole thread Raw
In response to Re: Making Vars outer-join aware  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: Making Vars outer-join aware
List pgsql-hackers


On Sun, Jul 10, 2022 at 12:39 PM Tom Lane <tgl@sss.pgh.pa.us> wrote:
Here's v2 of this patch series.  It's functionally identical to v1,
but I've rebased it over the recent auto-node-support-generation
changes, and also extracted a few separable bits in hopes of making
the main planner patch smaller.  (It's still pretty durn large,
unfortunately.)  Unlike the original submission, each step will
compile on its own, though the intermediate states mostly don't
pass all regression tests.

                        regards, tom lane

Hi,
For v2-0004-cope-with-nullability-in-planner.patch.
In remove_unneeded_nulling_relids():

+   if (removable_relids == NULL)

Why is bms_is_empty() not used in the above check ?
Earlier there is `if (bms_is_empty(old_nulling_relids))`

+typedef struct reduce_outer_joins_partial_state

Since there are already reduce_outer_joins_pass1_state and reduce_outer_joins_pass2_state, a comment above reduce_outer_joins_partial_state would help other people follow its purpose.

+       if (j->rtindex)
+       {
+           if (j->jointype == JOIN_INNER)
+           {
+               if (include_inner_joins)
+                   result = bms_add_member(result, j->rtindex);
+           }
+           else
+           {
+               if (include_outer_joins)

Since there are other join types beside JOIN_INNER, should there be an assertion in the else block ? e.g. jointype wouldn't be JOIN_UNIQUE_INNER.

Cheers

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