correction: Is there a way to have visibility on its usage?
thanks
On Wed, Jan 15, 2025 at 1:29 PM bruno vieira da silva <brunogiovs@gmail.com> wrote:
Hello All.
On pg 17 now we have better visibility on the I/O required during query planning.
so, as part of an ongoing design work for table partitioning I was analyzing the performance implications of having more or less partitions.
In one of my tests of a table with 200 partitions using explain showed a large amount of buffers read during planning. around 12k buffers.
I observed that query planning seems to have a caching mechanism as subsequent similar queries require only a fraction of buffers read during query planning.
However, this "caching" seems to be per session as if I end the client session and I reconnect the same query execution will require again to read 12k buffer for query planning.
Does pg have any mechanism to mitigate this issue ( new sessions need to read a large amount of buffers for query planning) ? or should I mitigate this issue by the use of connection pooling.
How is this caching done? Is there a way to have viability on its usage? Where is it stored?
