Pavan Deolasee wrote: > On 8/9/07, Bruce Momjian <[EMAIL PROTECTED]> wrote: > > > > I was wondering about HOT behavior. > > > > Will an INSERT reuse rows no longer visible caused by an UPDATE or > > DELETE, or if an UPDATE will reuse rows expired by an invisible DELETE? > > It seems both of these would be possible and useful. > > > > As the patch stands today, we don't take any pains to update the > FSM information after pruning and defraging the page. So FSM would > not consider the page for either INSERT or COLD UPDATE. Of course, > the page can still be used for INSERT if relation->rd_targetblock is > somehow set to this page. > > OTOH UPDATE will always reuse the dead space of either expired > updated rows or deleted rows or even aborted rows.
Well, that is very good news. -- Bruce Momjian <[EMAIL PROTECTED]> http://momjian.us EnterpriseDB http://www.enterprisedb.com + If your life is a hard drive, Christ can be your backup. + ---------------------------(end of broadcast)--------------------------- TIP 9: In versions below 8.0, the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match
