Configuring Large Cache Sizes

To configure large data and index cache sizes, add COMPATIBILITY LARGE_CACHE to the c-tree Server configuration file. This keyword permits the DAT_MEMORY and IDX_MEMORY values to be reinterpreted as megabytes instead of bytes.

If the byte value in the configuration file is less than or equal to 64000, then the value is reinterpreted as megabytes. This permits up to 64 GB of index or data cache to be requested. If the value is greater than 64000, it is interpreted as bytes (just as without the LARGE_CACHE option). If the LARGE_CACHE option is not used, the values for DAT_MEMORY and IDX_MEMORY are interpreted as bytes, regardless of their values.

Example

COMPATIBILITY  LARGE_CACHE

IDX_MEMORY     100000000

DAT_MEMORY     4096

This example requests 100 million bytes of index cache, and 4 GB of data cache.

Note: With excessively large cache sizes, it is quite likely you may experience a long delay during sever shutdown as the data is flushed to disk. This delay depends on how much of the data in cache is "dirty".