Use an absolute value to specify the default data cache and the procedure cache for SAP ASE.
The first step in planning cache configuration and implementing caches is to set the max memory configuration parameter. After you set max memory, determine how much space to allocate for data caches on your server. The size of a data cache is limited only by access to memory on the system; however, max memory should be larger than total logical memory. You must specify an absolute value for the size of the default data cache and all other user-defined caches.
You can configure data caches in two ways:
Interactively, using sp_cacheconfig and sp_poolconfig. This method is dynamic, which means you need not restart SAP ASE.
By editing your configuration file. This method is static, which means you must restart SAP ASE.
Each time you change the data cache or execute either sp_cacheconfig or sp_poolconfig, SAP ASE writes the new cache or pool information into the configuration file and copies the old version of the file to a backup file. A message giving the backup file name is sent to the error log.
Some of the actions you perform with sp_cacheconfig are dynamic and some are static.
You can specify both static and dynamic parameters in a single command. SAP ASE performs the dynamic changes immediately and writes all changes to the configuration file (both static and dynamic). Static changes take effect the next time the server is started.
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Dynamic sp_cacheconfig actions |
Static sp_cacheconfig actions |
|---|---|
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Adding a new cache |
Changing the number of cache partitions |
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Adding memory to an existing cache |
Reducing a cache size |
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Deleting a cache |
Changing replacement policy |
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Changing a cache type |
You can reset static parameters by deleting and re-creating the cache: