Each library has an internal directory that OpenEdge uses to access members. OpenEdge loads this directory into memory when it opens the library. The directory stays in memory until the library is closed.
By default, OpenEdge tries to load the entire directory of each library into memory. In some cases, you might not have enough available memory to store a library's entire internal directory. Use the PROLIB Memory (-plm) startup parameter to limit the size of a standard library's internal directory in memory. This parameter allocates a 512-byte cache for a standard library's directory. This parameter is especially useful when running in limited memory with several libraries opened simultaneously. If you specify the PROLIB Memory (-plm) startup parameter with memory-mapped libraries, OpenEdge ignores it.
If you run OpenEdge over a network and place a standard library on a file server, remote reads from the library might take longer than reading a r-code file and storing it locally in the r-code swap file. Use the PROLIB Swap (-pls) startup parameter to store standard library members locally in the r-code swap file. If you specify the PROLIB Swap (-pls) startup parameter with memory-mapped libraries, OpenEdge ignores it.
For more information about the PROLIB Memory (-plm) and PROLIB Swap (-pls) startup parameters, see OpenEdge Deployment: Startup Command and Parameter Reference.