Re: Removing unneeded self joins

Hi,
w.r.t. v33-0001-Remove-self-joins.patch :

removes inner join of plane table -> removes inner join of plain table
in an query plan -> in a query plan

+ * Used as the relation_has_unique_index_for,

Since relation_has_unique_index_for() becomes a wrapper of
relation_has_unique_index_ext, the above sentence doesn't make much sense.
I think you can drop this part.

but if extra_clauses doesn't NULL -> If extra_clauses isn't NULL

+ is_req_equal =
+ (rinfo->required_relids == rinfo->clause_relids) ? true : false;

The above can be simplified to:
is_req_equal = rinfo->required_relids == rinfo->clause_relids;

+ ListCell *otherCell;
otherCell should be initialized to NULL.

+ if (bms_is_member(k, info->syn_lefthand) &&
+ !bms_is_member(r, info->syn_lefthand))
+ jinfo_check = false;
+ else if (bms_is_member(k, info->syn_righthand) &&
+ !bms_is_member(r, info->syn_righthand))
+ jinfo_check = false;
+ else if (bms_is_member(r, info->syn_lefthand) &&
+ !bms_is_member(k, info->syn_lefthand))
+ jinfo_check = false;

I think the above code can be simplified:

If bms_is_member(k, info->syn_lefthand) ^ bms_is_member(r,
info->syn_lefthand) is true, jinfo_check is false.
If bms_is_member(k, info->syn_righthand) ^ bms_is_member(r,
info->syn_righthand) is true, jinfo_check is false.
Otherwise jinfo_check is true.

Cheers