we're planning some work on our SQL Query Plan functionality for a future release of InterSystems IRIS and are interested to hear how you're using them today, or what'd keep you from using them. Rather than try and fit everything in a rigid survey, I thought a simple thread on our beloved DC might also reveal some use patterns that we support or could do a better job on. Some questions to get you started (but hoping they don't constrain your spontaneous creativity!):
- When do you go look for a query plan?
- How are you currently accessing query plans? Using $SYSTEM.SQL.ShowPlan() in ObjectScript, through EXPLAIN or SHOW PLAN over SQL or just through the SMP?
- Are there any pieces of information that are missing from the raw plan that you'd typically look up through catalog queries or class definitions? Any you're lacking but wouldn't even know how to find?
- When you have that cunning plan right in front of you, what do you do with it?
- Do you ever look at alternate query plans?