Is COST_CATEGORY = 'A'? If 'B', RUNSTATS first. 3. **Read PLAN_TABLE** — Identify ACCESSTYPE, MATCHCOLS, METHOD, PREFETCH for each step 4. **Compare to expected plan** — Do you know what the plan *should* be? If not, work it out from the indexes and predicates. 5. **Check catalog statistics** — Quer