Default: Enabled (for 1000 elements). To completely disable the data cache feature, set it to 0 (zero).
Purpose
The DATA_CACHE parameter specifies the data cache size (in entries). The data cache is used to store the results of conversions from text strings to internal date format. The cache is useful because the cost of looking up dates is much less than converting from text format to date format. If the same dates occur repeatedly in the date file, then using the data cache can improve the speed of a direct path load.
Syntax and Description
DATA_CACHE=n
Every table has its own data cache, if one is needed. A data cache is created only if at least one date or timestamp value is loaded that requires data type conversion in order to be stored in the table.
The data cache feature is enabled by default. The default data cache size is 1000 elements. If the default size is used and the number of unique input values loaded exceeds 1000, then the data cache feature is automatically disabled for that table. However, if you override the default and specify a nonzero data cache size and that size is exceeded, then the cache is not disabled.
You can use the data cache statistics (entries, hits, and misses) contained in the log file to tune the size of the cache for future similar loads.
See Also:
Restrictions
The data cache feature is only available for direct path and external tables loads.
Example
The following specification completely disables the data cache feature.
DATA_CACHE=0