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From: Tom Lane <tgl@sss.pgh.pa.us>
To: David Rowley <dgrowleyml@gmail.com>
cc: Andrew Dunstan <andrew@dunslane.net>, Richard Guo <guofenglinux@gmail.com>,
        jian he <jian.universality@gmail.com>,
        PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Subject: Re: Revert: Remove useless self-joins *and* -DREALLOCATE_BITMAPSETS make server crash, regress test fail.
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Comments: In-reply-to David Rowley <dgrowleyml@gmail.com>
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David Rowley <dgrowleyml@gmail.com> writes:
> I'm fine with this one as it's the same as what I already mentioned
> earlier.  I had imagined doing bms_del_member(bms_copy ... but maybe
> the compiler is able to optimise away the additional store. Likely, it
> does not matter much as pallocing memory likely adds far more overhead
> anyway.

I actually wrote it that way to start with, but undid it after
noticing that the existing code in remove_rel_from_restrictinfo
does it in separate steps, and thinking that that was good for
both separation of concerns and a cleaner git history.  I too
can't believe that an extra fetch will be noticeable compared
to the cost of the adjacent bms_xxx operations.

			regards, tom lane