On Sun, 2010-02-14 at 17:06 +0000, Greg Stark wrote: > On Sun, Feb 14, 2010 at 2:59 PM, Simon Riggs <si...@2ndquadrant.com> wrote: > > Optimize GetConflictingVirtualXIDs() in roughly the same manner we > > optimize TransactionIdIsInProgress(). > > > > Views? > > EINSUFFICIENTEXPLANATION :)
...I like that error code. The patch adds a calculation of RecentGlobalXmin each time it accesses the proc array to derive conflicts. It then uses the derived value to provide a fast-path out if a potential snapshot conflict arrives that we already know will not conflict with any backends. The purpose of this is to reduce the number of scans of the procarray and improve the performance of the startup process. The mechanism and purpose is the same as the first check in TransactionIdIsInProgress(). -- Simon Riggs www.2ndQuadrant.com -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
