FILES=<# File buffers>,<# ISAM buffers>

Example:  FILES=40,40

In order to keep track of files opened within programs, A-Shell allocates internal file buffers within the memory partition (see MEMORY statement.) Each file buffer requires approximately 80 bytes, and each ISAM buffer approximately 300 bytes. In order to save memory, or to support an extended number of files, the number of buffers may be changed, according to the following rules. Note that the buffer values refer to the maximum number of files which may be simultaneously open at any one time.

ISAM buffers are only used for ISAM 1.x files. If your application makes use of only sequential, random, and ISAM PLUS files, the number of ISAM buffers may be set to zero. Sequential, random, and ISAM PLUS files require only a single FILE buffer each. An ISAM 1.X file requires two FILE buffers and one ISAM buffer for the initial open of the main index, while each subsequent secondary index requires just one FILE buffer, and one ISAM buffer.

Notes

The default number of buffers is 40 FILE and 40 ISAM, in order to maintain compatibility with earlier versions of A-Shell.

The FILES parameter only adjusts A-Shell’s internal resource allocations; you may need to adjust the parameters for your operating system locking mechanism to allocate enough locking resources for large numbers of open files.

The operating system and/or environment may further impose limits on the maximum number of open files. Under UNIX, there are typically kernel configuration variables which set the limit, although it may be further limited by the shell.