Query planning read a large amount of buffers for partitioned tables

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?

Thanks
--
Bruno Vieira da Silva