Symbol garbage collection of unreferenced symbols runs during markForCollection, if the configuration parameter STN_SYMBOL_GC_ENABLED is set to true. STN_SYMBOL_GC_ENABLED is false by default.
Symbol garbage collection has a small risk that a symbol that is still referenced may be collected, if there are users logged in and performing commits that result in a new reference to that symbol during Symbol garbage collection.
Note that due to bug 49339, Symbol garbage collection was subject to similar problems in earlier versions.
STN_SYMBOL_GC_ENABLED is false by default. To avoid risk, only turn this on to enable symbol garbage collection during maintenance periods, when sessions other than the MFC session are not running.
Last updated: 3/7/22