Re: Tunning.

Bashar Chalabi wrote: > > >>LRU_MAX_DIRTY 60 # LRU percent dirty begin cleaning limit > >>LRU_MIN_DIRTY 50 # LRU percent dirty end cleaning limit> > > >For OLTP, try decreasing both of these. Try 2 and 1 or 2 and 0. > > Why? > > The only reason I can think of is to reduce checkpoint time, but surely > there must be dramatic performance implications (of the negative kind). Nope only dramatic performance implications of the positive kind! The only reason to trade LRU writes (between checkpoints using the low LRU_MIN/MAX_DIRTY parameter values) for Chunk writes (at checkpoint time) is to avoid the engine having a negative impact on OTHER applications by doing its I/O in dribs and drabs all day long. HOWEVER, the engine will run smoother this way and you will experience shorter checkpoint duration, as you note, which will improve update performance. Art S. Kagel