Vijaykumar Jain wrote: > I was asked this question in one of my demos, and it was interesting one. > > we update xmin for new inserts with the current txid. > now in a very high concurrent scenario where there are more than 2000 > concurrent users trying to insert new data, > will updating xmin value be a bottleneck? > > i know we should use pooling solutions to reduce concurrent > connections but given we have enough resources to take care of > spawning a new process for a new connection, You can read the function GetNewTransactionId in src/backend/access/transam/varsup.c for details. Transaction ID creation is serialized with a "light-weight lock", so it could potentially be a bottleneck. Often that is dwarfed by the I/O requirements from many concurrent commits, but if most of your transactions are rolled back or you use "synchronous_commit = off", I can imagine that it could matter. It is not a matter of how many clients there are, but of how often a new writing transaction is started. Yours, Laurenz Albe -- Cybertec | https://www.cybertec-postgresql.com
