On 09/18/2015 10:47 AM, Tom Lane wrote:
Jan Wieck <j...@wi3ck.info> writes:
Attached is a complete rework of the fix from scratch, based on Tom's
suggestion.


The code now maintains a double linked list as suggested, but only uses
it to mark all currently valid entries as invalid when hashvalue == 0.
If a specific entry is invalidated it performs a hash lookup for maximum
efficiency in that case.

That does not work; you're ignoring the possibility of hashvalue
collisions, and for that matter not considering that the hash value
is not equal to the hash key.  I don't think your code is invalidating
the right entry at all during a foreign key constraint update, and
it certainly cannot do the right thing if there's a hash value collision.

Attached is something closer to what I was envisioning; can you do
performance testing on it?

Sorry for the delay.

Yes, that patch also has the desired performance for restoring a schema with hundreds of thousands of foreign key constraints.


Regards, Jan

--
Jan Wieck
Senior Software Engineer
http://slony.info


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