Hi, |Cc: pgsql-novice@xxxxxxxxxxxxxx, pgsql-performance@xxxxxxxxxxxxxx Please don't cross post to multiple lists. On Thu, Apr 04, 2019 at 08:18:01PM +0530, Prasad wrote: > There are lot of allocations in postgresql.conf file, for example > shared_buffers, work_mem...etc. > > As per my knowledge, all postgres processes should not consume the RAM more > than the value assigned in shared_buffers.Please clarify and let me know if > I misunderstand the concept.. shared_buffers is what's *reserved* for postgres and unavailable for other processes whenever PG is running. work_mem is what each postgres process might use, if needed. When complete, that's returned to the OS. Note that an expensive query might actually use some multiple of work_mem (it's per sort/hash node and also per parallel process, and also hash aggregate can sometimes use more than work_mem). Justin
