On Tuesday February 24 2004 1:14, Kevin Brown wrote: > > One problem I've been running into is the merge join spilling to disk > because sort_mem isn't big enough. The problem isn't that this is > happening, it's that I think the planner is underestimating the impact > that doing this will have on the time the merge join takes. Does the > planner even account for the possibility that a sort or join will spill > to disk? Spilling to disk like that will suddenly cause sequential > reads to perform much more like random reads, unless the sequential > scans are performed in their entirety between sorts/merges.
How do you know the merge join is spilling to disk? How are you identifying that? Just assuming from vmstat? iostat? ---------------------------(end of broadcast)--------------------------- TIP 4: Don't 'kill -9' the postmaster
