VMS Help Sys Parameters, ACP_XQP_RES  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    ACP_XQP_RES controls whether the XQP is currently in memory.
    The default value (1) specifies that the XQP is permanently in
    memory. Change the default only on restricted memory systems
    with a small number of users and little or no file activity that
    requires XQP intervention. Such activity includes file opens,
    closes, directory lookups, and window turns.