Hinted by this thread: http://archives.postgresql.org/pgsql-performance/2006-01/msg00016.php
I wonder if we should really implement file-system-cache-warmup strategy which we have discussed before. There are two natural good places to do this: (1) sequentail scan (2) bitmap index scan We can consider (2) as a generalized version of (1). For (1), we have mentioned several heuristics like keep scan interval to avoid competition. These strategy is also applable to (2). Question: why file-system level, instead of buffer pool level? For two reasons: (1) Notice that in the above thread, the user just use "shared_buffers = 8192" which suggest that file-system level is already good enough; (2) easy to implement. Use t*h*r*e*a*d? Well, I am a little bit afraid of mention this word. But we can have some dedicated backends to do this - like bgwriter. Let's dirty our hands! Comments? Regards, Qingqing ---------------------------(end of broadcast)--------------------------- TIP 5: don't forget to increase your free space map settings