Product Documentation

FairCom ISAM for C

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Memory File Limitations

Memory files are subject to the following limitations:

  • A memory file cannot be mirrored, partitioned, or segmented.
  • A memory file cannot be backed up by a dynamic dump.
  • The ISAM rebuild function RebuildIFile() does not support rebuilding indexes associated with a memory data file; instead use the low-level RebuildIIndex() function to rebuild individual indexes.
  • The restorable delete (ctRSTRDEL) attribute is not supported for memory files.
  • The atomic, recoverable transaction control attribute (ctTRNLOG) is not supported for memory files. However, the atomic, non-recoverable transaction control (ctPREIMG) and the transaction-dependent (ctTRANDEP) attributes are supported for memory files.
  • FairCom Replication isn't supported for memory files.
  • When traversing memory files in “physical order” there is no guarantee of any particular ordering. The sequence of FirstRecord(), NextRecord() operations will traverse records ordered by their internal hash table positioning, which can be quite different from a typical physical ordering on disk.
  • Be sure to see HUGE File Support for additional requirements.