Used to compute the maximum amount of memory that hash-based operations can use. The final limit is determined by multiplying work_mem by
hash_mem_multiplier. The default value is 1.0, which makes hash-based operations subject to the same simple work_mem maximum as sort-based operations.
hash_mem_multiplier in environments where spilling by query operations is a regular occurrence, especially when simply increasing work_mem results in memory pressure (memory pressure typically takes the form of intermittent out of memory errors). A setting of 1.5 or 2.0 may be effective with mixed workloads. Higher settings in the range of 2.0 - 8.0 or more may be effective in environments where work_mem has already been increased to 40MB or more.
- Some comment problem in nodeAgg.c
- Removing "long int"-related limit on hash table sizes
- Re: Removing "long int"-related limit on hash table sizes
- Re: Delegating superuser tasks to new security roles (Was: Granting control of SUSET gucs to non-superusers)
- Re: Hybrid Hash/Nested Loop joins and caching results from subplans