Temporary storage filesystem

The filesystem that qdb uses for temporary storage must support POSIX file locking. File locking is required for database vacuuming.

qdb checks its temporary storage as follows:

• If the tempstore option (-o tempstore) is specified on the command line, qdb checks to see if the specified location:
  • exists
  • is writable
  • is not /dev/shmem
  • is not a link to /dev/shmem

  If all the above conditions are met, qdb sets the internal temporary storage to the location specified by the tempstore option. If any of the above conditions are not met, qdb logs errors to the slog and fails to start up.

• If no tempstore option (-o tempstore) is specified on the command line, qdb uses the environment variable TMPDIR to obtain the location it should use for temporary storage. qdb checks if TMPDIR exists and the location specified by this variable:
  • exists
  • is writable
  • is not /dev/shmem
  • is not a link to /dev/shmem

  If all the above conditions are met, qdb sets the internal temporary storage to the value of TMPDIR. If any of the above conditions are not met, qdb logs errors to the slog and fails to start up.