On Tue, Feb 19, 2019 at 07:08:14AM +0000, Tsunakawa, Takayuki wrote:
> We all have to manage things within resource constraints. The DBA
> wants to make sure the server doesn't overuse memory to avoid crash
> or slowdown due to swapping. Oracle does it, and another open source
> database, MySQL, does it too. PostgreSQL does it with shared_buffers,
> wal_buffers, and work_mem (within a single session). Then, I thought
> it's natural to do it with catcache/relcache/plancache.
I already addressed these questions in an email from Feb 14:
https://www.postgresql.org/message-id/20190214154955.GB19578@momjian.us
I understand the operational needs of limiting resources in some cases,
but there is also the history of OS's using working set to allocate
things, which didn't work too well:
https://en.wikipedia.org/wiki/Working_set
I think we need to address the most pressing problem of unlimited cache size
bloat and then take a holistic look at all memory allocation. If we
are going to address that in a global way, I don't see the relation
cache as the place to start.
--
Bruce Momjian <bruce@momjian.us> http://momjian.us
EnterpriseDB http://enterprisedb.com
+ As you are, so once was I. As I am, so you will be. +
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