File Handles

The OpenEdge RDBMS uses file handles (a UNIX term, roughly equivalent to the number of open files) when reading and writing to the database and related files. Most operating systems limit the number of file handles a user process can allocate at one time.

Use the following formula to determine the number of file handles used:

H = Static Handles + (# of .dn files) + (# of .bn files) + (# of .an files)

The elements of the above equation are defined as follows:

H — The number of file handles the OpenEdge RDBMS uses.

Static Handles — The number of handles allocated for any OpenEdge database. The number of static file handles that the process requires depends on whether you are running a client process or a server process:

Client — Requires ten file handles (PROMSGS + LG + DB + LBI + SRT + RCD + STDIN STDOUT + 2). The file handles used for the input and output devices (STDIN and STDOUT) are allocated by the operating system.

Server — Requires five handles (PROMSGS + LG + DB + 2).

# of .dn files — The number of DB files defined for the database.

# of .bn files — The number of BI files defined for the database.

# of .an files — The number of AI files defined for the database.

Additional file handles are consumed as follows:

If you are running a server in a UNIX environment that uses sockets for interprocess communication, add one file handle for each user.

Application programs use additional file handles when reading and writing text files and when compiling programs. The maximum number of file handles supported by the AVM (ABL Virtual Machine) is 256.