Default: Enabled (for 1000 elements). To completely disable the date cache feature, set it to 0 (zero).
Purpose
The DATE_CACHE parameter specifies the date cache size (in entries). The date 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 data file, then using the date cache can improve the speed of a direct path load.
Syntax and Description
DATE_CACHE=n
Every table has its own date cache, if one is needed. A date 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 date cache feature is enabled by default. The default date cache size is 1000 elements. If the default size is used and the number of unique input values loaded exceeds 1000, then the date cache feature is automatically disabled for that table. However, if you override the default and specify a nonzero date cache size and that size is exceeded, then the cache is not disabled.
You can use the date cache statistics (entries, hits, and misses) contained in the log file to tune the size of the cache for future similar loads.
Restrictions
The date cache feature is only available for direct path and external tables loads.
Example
The following specification completely disables the date cache feature.
DATE_CACHE=0