Re: improving foreign key locks - Mailing list pgsql-hackers

From Florian Pflug
Subject Re: improving foreign key locks
Date
Msg-id DFE17B65-07DD-469E-AFEA-536756F9D3B1@phlo.org
Whole thread Raw
In response to Re: improving foreign key locks  (Jim Nasby <jim@nasby.net>)
List pgsql-hackers
On Dec2, 2010, at 00:59 , Jim Nasby wrote:
> On Dec 1, 2010, at 11:09 AM, Florian Pflug wrote:
>> An UPDATE on such a SHARE locked row would be allowed despite the lock if it only changed columns not mentioned by
anyunique index. 
>
> On a side-note, by "changed columns" do you mean the column appeared in the UPDATE statement, or the data actually
changed?I suspect the former might be easier to implement, but it's really going to fsck with some applications (Rails
isone example that comes to mind). 

The most sensible thing to do is probably to make it mean "columns whose new value's binary representation differs from
theold value's binary representation". That is also what is checked for HOT updated I believe, though I didn't
recheck...

best regards,
Florian Pflug



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