Setting high values for TXSeries managed shared memory pool
How to set a memory beyond 256 MB for Region Pool or Task Shared Pool?
TXSeries runs as a 32-bit application. In AIX, the 32-bit memory model provides addressable segments of 256 MB in size. TXSeries uses the large memory model of AIX. Hence, the heap-size of the region processes can be up to one (1) GB size. That is, four (4) segments of 256 MB each.
If you need to allocate one (1) GB for region pool memory, then you need to ensure four consecutive free segments to be available for allocation from the address provided in RegionPoolBase in RD.stanza.
For example, if the MaxRegionPool is set to 1073741824 (1 GB) in RD.stanza and RegionPoolBase is set to 2415919104 (0x90000000), that is the ninth segment, then the segment A, B and C which follows this ninth segment must be free to accommodate this new region pool size.