Filtering non-indexed date causes spool errors. Alternative approach:
SELECT uid, acct, dt, MAX(val) AS max_val
FROM tdata
WHERE dt >= 190101
GROUP BY uid, acct, dt;
Optimization suggestions?
hey, try adding a computed col index on dt. it helped reduce spool errors. using a computed filter rather than raw dt filter sped up my query a lot. might work for you too, give it a try.
It is helpful to examine alternative approaches when indexing changes are not feasible. Converting the dt column into a proper date type could lead to intrinsic performance gains even without a direct index. This approach can often reduce the unnecessary conversion overhead during query time. In my experience, reengineering the table schema to handle dates appropriately not only clarifies intent but also permits the query optimizer to work more efficiently. Investigating partitioning strategies based on the date attribute might further limit the data volume processed by the query.