G
gus bjorklund
Guest
I have seen two major bottlenecks in atm and quite a few other applications: one is that rm chain one that you observed and the other is on BKEX wait for index blocks while creating index entries. the index waits are more common because usually there are multiple indexes on a table so you allocate record space once but create index entries multiple times. while there is lock overhead for sequence increments, it is much less than for space allocation. transactions that are in begin status have not yet made any database changes and but i guess they could incur rm chain waits while looking for space to make their first database change. i did see performance gains from using 4 history tables in atm. have not done so for a while though.
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