Product Documentation

Database Administrator's Guide

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To configure large data and index cache sizes, add COMPATIBILITY LARGE_CACHE to the FairCom 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 64GB 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.



IDX_MEMORY 100000000


Requests 100 million bytes of index cache, and 4 GB of data cache.


  • The FairCom Server does not check that the specified amount of memory actually exists as available physical memory on the system. To avoid FairCom Server startup errors or performance degradation due to memory swapping, ensure that enough physical memory is available to accommodate the specified data and index cache sizes.
  • The FairCom Server does not support this option on systems that do not support LARGE_CACHE. These systems are identified as 32-bit systems that do not have SYS_LONG8 defined in their ctcmpl.h include file.