The diff is in an area I do not know. What do I do?
Say so and review what you can: tests, error handling, whether the description matches the change. An approval that means "I did not understand this" is worse than no review, and a question in the thread is often more useful than the approval would have been.
Tool steps: 3 (reasoning summary, call to python, execution output)
rows = run_sql("EXPLAIN (ANALYZE) SELECT ...")
print(rows[:3])Seq Scan on events (cost=0.00..812431.00 rows=41203122 width=16)
Rows Removed by Filter: 38996878
Planning Time: 0.214 ms
Execution Time: 11842.663 msBig PRs sit for days. How do we fix that?
Make them smaller, because attention does not scale with size: a 50 line change gets real review, a 2000 line change gets a rubber stamp. Splitting by mechanical versus meaningful is the easiest cut, since the mechanical half needs eyes but not thought.
How do I review without turning it into style comments?
Automate style entirely, then the review can only be about substance. What remains worth saying: this breaks under concurrency, this loses an error, this name means something else in our codebase. If a comment could be a lint rule, make it one.
How long does this usually take in practice?
An afternoon to do it properly the first time, then minutes when it recurs. Most of the first afternoon goes into discovering which of the defaults do not match your situation.