HS_DESCRIBE_CACHE_HWM

Default value:	100
Range of values:	1 to 4000

Specifies the maximum number of entries in the describe cache used by Heterogeneous Services. This limit is known as the describe cache high water mark. The cache contains descriptions of the mapped tables that Heterogeneous Services reuses so that it does not have to re-access the non-Oracle datastore.

Increase the high water mark to improve performance, especially when you are accessing many mapped tables. Note that increasing the high water mark improves performance at the cost of memory usage.