-904 unavailable resource - where do I even start?

DSNT408I SQLCODE = -904 ... REASON 00C90096, TYPE 00000302, RESOURCE NAME looking like hex junk.

I know -904 means something is unavailable. How do people decode this without guessing for an hour?

Manual first: reason code + resource type. Those two tell you whether it is a tablespace, DBD, package, temp database, whatever.

Then look at what happened right before (utility, STOP DATABASE, full log, max connections). Forum answers stay generic because the "why" is always local.

In CEDF I have seen -904 on OPEN CURSOR with reason pointing at TEMP DATABASE, then the next FETCH is -501 because the open never stuck. Fix the -904 first.