Cached Results

CalcCache Cached Results

storing calculation results

Calculated results are stored persistently in the CalcCache, if the following conditions are met:

  • The results relate to the calculation rule of a named tree item. Results of sub-expression might be stored in the transient cache (only available within session) but not stored persistently.
  • The data size of the results exceeds a specified threshold (small results are by default not stored, see StoreData property). The threshold has a default value of 4.000 bytes. This value can be changed in the GeoDMS GUI with the Tools > Options menu. Open the Current Configuration tab and edit the Minimum size for DataItem specific swapfiles in the CalcCache option. It is advised to keep this value limited.
  • The value of the FreeData property is False.
  • For the derivation of the results, no session-specific function was used.
  • The calculation result is not a data item that results directly from a composite function (both root result and subitem) or a direct reference thereto. Results derived indirectly from a composite function, will be stored persistently if they meet all other conditions.

Calculation Results from MetaScript functions are new tree items, for which resulting data can be stored in the CalcCache, if they meet the above conditions.

transient CalcCache

The CalcCache contains a transient part, with calculation results that might be re-usable during a session, but that are deleted when the application is closed. This transient part of the CalcCache is stored in the .tmp subfolder of the CalcCache root folder. This part functions as an extension of the page file mechanism, useful to the relieve the use internal memory and to cope with the 1 gigabyte limit in the 32 bits environment.

== StoreData Property (default value = “False”) == If the property StoreData = “True” is configured, condition two (data size) does not longer apply. Use the StoreData property to store results that have a data size less than the threshold, but are time consuming to recalculate. If the StoreData property is not configured (or explicitly configured as “False”), only data items with a data size above the threshold are stored.

== FreeData property (default value = “True” since version 7.122) == The property FreeData = “False” need to be configured for a data item to store the calculation results of the item and it’s subitems in the CalcCache. We advice to configure FreeData = “False” only for those items or containers that require substantial calculation time, have steady definitions and are used more often than they need to be recalculated. This will limit the CalcCache size and the disk I/O. Never configure FreeData = “False” for results of the id, const and similar functions as they are faster to recalculate as reading them from a disk.

== KeepData property (default value = “False”) == The KeepData property has no effect on the CalcCache. If the KeepData is configured to True, the results of the item is kept in memory even if there is no interest from any view. Configuring the KeepData property becomes more relevant when less items are Cached. Configure this property to True on items that are relevant for interactive working. We advice to configure this especially for items used in for_each functions, which also results in configurations that will expand faster.