Clearing DataGate's DG8_VCAT72 library

Question

Can DataGate’s IBM i DG8_VCAT72 library be cleared? There are over 11,000 objects in this library, some dating back to 2016. Please help!

Answer

The DG8_VCAT72 library is an IBM library that caches DataGate file definitions. This cache library is shared by all installed instances of DataGate for IBM i.

You can clear this cache/library the DG8_VCAT72 library with the IBM i command CLRLIB—but do not do that with any active DataGate user jobs. (Active DataGate user jobs are DG8_NET jobs. Read more about them here). Before attempting to clear DG8_VCAT72, use WRKACTOB to ensure there are no DG8_NET jobs active.

If you try to clear DG8_VCAT72 with active user jobs, the active users will immediately get a non-responsive app and those jobs will lock-up and need manual attention to remove. Except for very old versions of DataGate, this library is always named DG8_VCAT72.

After clearing the cache, you may notice a slight performance hit for a couple of hours as the cache is rebuilt. On a heavily-used system it won’t take very long for the cache to repopulate.

Under normal circumstances you don’t want to clear this library because it does significantly improve DataGate performance. However, there may be times where it has acquired a number of unused or stale cached file definitions or if your disk space is running so dangerously low that you need disk space. In that case, use CLRLIB (as explained above) to clear this library.

You may also need to clear DG8_VCAT72 if you get this error message:

Acceler8DB Error: Corrupt file definition cache member.

That error usually means the cache contains a corrupt member—probably as the result of an end-user job that ended abnormally.