Alexey,
The issue is that the 1/4 memory suggestion hasn't been a recommendation in quite a while. Now that much larger amounts
ofRAM are readily available, tests have been finding out that more than 8GB of RAM in shared_buffers has diminishing or
evenworse returns. This is true for any version. Further, since PostgreSQL manages its own memory, and the Linux Kernel
alsomanages various caches, there's significant risk of storing the same memory both in shared_buffers, and in file
cache.
There are other tweaks the tool probably needs, but I think this, more than anything else, needs to be updated. Until
PGsolves the issue of double-buffering (which is somewhat in progress since they're somewhat involved with the Linux
kerneldevs) you can actually give it too much memory.
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