Hi, The Current architecture of Updates in PostgreSQL is 1) Make a select query out of update. It involves a READ lock/BUFFER_SHARE 2) Get the tupleid 3) Goto the buffer containing the tupleid, make a BUFFER_EXCLUSIVE lock on it 4) update it 5) Repeat the above process for subsequent rows
I propose to change this row-by-row approach, when it is a full table update. I plan to send a extra flag(which will be set for Full table Deletes/Updates). this would make the access method directly acquire the exclusive lock and update the existing record. For Deletes this is simple. But for updates, the projection tuple has to be made before re-inserting it. So there will be a list of Heap tuples stored in memory for each page getting updated. these tuples will be inserted after the deletion part of update is done. This is just a rough design. I may get involved in a detail design once i get a nod from the mailing list community. Thanks, Gokul.
