I don't think this should involve much code change. But no-one interested????
On Sat, Mar 27, 2010 at 2:23 AM, Gokulakannan Somasundaram < gokul...@gmail.com> wrote: > Hi, > Since we insert a new entry into the index for every update that's being > made into the table, we inevitably make a unique check against the older > version of the newly inserted row, even when the values are not updated. Of > course i am talking about non-HOT updates. (We will not go to the index for > HOT updates) > > a) The page which contains the index entry is Exclusively locked > b) We go ahead and visit the heap page for its HeapTupleSatisfiesDirty. > > If we have the information of the old tuple(its tuple-id) after a heap > update, during the index insert, we can avoid the uniqueness check for this > tuple,as we know for sure that tuple won't satisfy the visibility criteria. > If the table has 'n' unique indexes it avoids 'n' heap tuple lookups, also > increasing the concurrency in the btree, as the write lock duration is > reduced. > > Any comments? > > Thanks, > Gokul. >
