Adjusting the amount of memory for DSS and PDQ queries
You can estimate the amount of shared memory to allocate to decision-support (DSS) queries. Then, if necessary, you can adjust the value of the DS_TOTAL_MEMORY configuration parameter, which specifies the amount of memory available for PDQ queries.
DS_TOTAL_MEMORY = p_mem - os_mem - rsdnt_mem -
(128 kilobytes * users) - other_mem
- p_mem
- represents the total physical memory that is available on the host computer.
- os_mem
- represents the size of the operating system, including the buffer cache.
- resdnt_mem
- represents the size of HCL OneDB™ resident shared memory.
- users
- is the number of expected users (connections) specified in the NETTYPE configuration parameter.
- other_mem
- is the size of memory used for other (non-HCL® OneDB) applications.
The value for DS_TOTAL_MEMORY that is derived from this formula serves only as a starting point. To arrive at a value that makes sense for your configuration, you must monitor paging and swapping. (Use the tools provided with your operating system to monitor paging and swapping.) When paging increases, decrease the value of DS_TOTAL_MEMORY so that processing the OLTP workload can proceed.
memory_grant_basis = (DS_TOTAL_MEMORY/DS_MAX_QUERIES) *
(PDQPRIORITY / 100) *
(MAX_PDQPRIORITY / 100)
memory_for_single_query = DS_TOTAL_MEMORY *
(PDQPRIOIRTY / 100) *
(MAX_PDQPRIORITY / 100)