rihad <rihad(at)mail(dot)ru> writes:
> Thanks! Our autovacuum_work_mem = 1GB, so this probably means any space
> would be available for reuse only at the end of the vacuum?
It's six bytes per dead tuple, last I checked ... you do the math.
> Are there
> any downsides in decreasing it to, say, 64MB? I see only pluses )
Well, usually people prefer to minimize the number of passes over
the indexes.
regards, tom lane