Five copy-paste templates from the main lesson
(01_AI_ASSISTED_QUERY_TUNING_WORKFLOW.md), collected here for direct use
in an IDE snippet library or team wiki. Each is designed to build a
validation step into the prompt itself rather than treating validation as
a separate, easily-skipped afterthought.
Use when you want diagnosis before any suggested fix.
I'm running [ENGINE + VERSION, e.g. "PostgreSQL 16"]. Here is my schema:
[PASTE CREATE TABLE + existing indexes]
Here is my query and its EXPLAIN (ANALYZE, BUFFERS) output:
[PASTE QUERY]
[PASTE EXPLAIN OUTPUT]
Walk through the plan node by node. For each node, tell me what it's doing
and whether the estimated vs. actual row counts suggest a cardinality
misestimate. Do not suggest a fix yet -- I want your diagnosis first.
Use before creating any AI-suggested index.
Given this schema and query [PASTE], suggest an index that would help.
For your suggestion, explicitly state:
1. The exact column order and why that order matters for this query
2. Whether an existing index already partially covers this
3. The write-side cost (INSERT/UPDATE/DELETE overhead) of adding it
4. One scenario where this index would NOT be chosen by the planner
Use for any suggested query rewrite, before merging it.
Here is a query I want to optimize: [PASTE]
Propose a rewrite. Then, separately, write a verification query I can run
that proves the original and rewritten queries return identical result
sets (same rows, same order if order matters, same NULL handling) against
my actual data -- not just an argument for why they should be equivalent.
Use as a mandatory follow-up to any suggestion before acting on it.
You suggested [PASTE THE MODEL'S PRIOR SUGGESTION].
Before I implement this: what assumption about my data distribution,
cardinality, or engine version would make this suggestion NOT help, or
actively make performance worse? Be specific, not generic.
Use with PERFORMANCE_SMELLS.md or Lesson 10’s
COST_SMELLS.md open alongside the suggestion.
Here is a catalog of performance anti-patterns my team maintains:
[PASTE RELEVANT ENTRIES FROM PERFORMANCE_SMELLS.md / COST_SMELLS.md]
Here is a query and a proposed rewrite: [PASTE BOTH]
Does the rewrite eliminate any smell in this catalog? Does it introduce
any smell in this catalog that the original didn't have? Answer both
questions explicitly, referencing specific catalog entries.
None of these templates replace the mandatory human validation steps in the main lesson. They structure the prompt so the model’s response is easier to verify — they do not make the response verified.