Question 330
At Lakeside Research, the science data operations team maintains a research experiment and analytics relational database with requirements for reproducible database workloads and protected experimental data. The acceptance review requires independent evidence for: A stored procedure occasionally chooses an inefficient execution plan after parameter changes and the team blindly rebuilds every table index. Which observed result BEST proves the intended problem is corrected?
Explanation
Correct Answer
The stabilized query uses an appropriate plan for representative parameter sets and duration variance falls without global index rebuilds. That observable result supports resolution of: A stored procedure occasionally chooses an inefficient execution plan after parameter changes and the team blindly rebuilds every table index. The corresponding corrective change is: Compare Query Store plans and runtime statistics to isolate parameter sensitivity and consider a supported plan or query correction. The Lakeside Research reviewer can distinguish demonstrated database behavior from an untested change claim.
Incorrect Answers
The actual plan demonstrates corrected cardinality and reduced work for the representative parameter set. That result is evidence for another corrective change: Compare estimated and actual plans with row counts and resource metrics to identify estimation or join-selection problems. The alternative problem is: A SQL DBA sees an estimated execution plan only and concludes a query cannot have cardinality estimation errors at runtime. The current Lakeside Research issue is instead: A stored procedure occasionally chooses an inefficient execution plan after parameter changes and the team blindly rebuilds every table index. Its decisive acceptance evidence would be: The stabilized query uses an appropriate plan for representative parameter sets and duration variance falls without global index rebuilds.
The same query has historical plan and runtime records that identify the regressed plan and its performance difference. That result is evidence for another corrective change: Enable and configure Query Store with appropriate capture and retention policies before diagnosing plan performance regressions. The alternative problem is: A frequently executed Azure SQL query regresses after an application update but Query Store is disabled, leaving no historical plan comparison. The current Lakeside Research issue is instead: A stored procedure occasionally chooses an inefficient execution plan after parameter changes and the team blindly rebuilds every table index. Its decisive acceptance evidence would be: The stabilized query uses an appropriate plan for representative parameter sets and duration variance falls without global index rebuilds.
The targeted query uses an effective seek or narrower scan with fewer logical reads and acceptable write overhead. That result is evidence for another corrective change: Evaluate an appropriate nonclustered index using predicates, selectivity and maintenance costs, then test the actual execution plan. The alternative problem is: A reporting query scans a very large transaction table for a selective customer ID because the table lacks a useful access path. The current Lakeside Research issue is instead: A stored procedure occasionally chooses an inefficient execution plan after parameter changes and the team blindly rebuilds every table index. Its decisive acceptance evidence would be: The stabilized query uses an appropriate plan for representative parameter sets and duration variance falls without global index rebuilds.