Track · 2:48 · Liner note

Index Scan Drift

Name: Index Scan Drift
Duration: 2 min 48 s
Description: An index scan reads rows through an index instead of the whole table, and the drift in the title points at how query plans and performance slowly change as data volume and statistics evolve.

An index scan reads rows through an index instead of the whole table, and the drift in the title points at how query plans and performance slowly change as data volume and statistics evolve.

Nothing broke. The query is the same, the index is still there, and yet latency has crept up a few milliseconds each week. Index Scan Drift is that slow change: data grows, statistics age, and the planner quietly picks a different route.

Keep it running while you pull the execution plan and compare it with last month’s. The fix is often dull: fresher statistics, a better key, a narrower scan. The lesson is to watch trends, because performance rarely fails all at once.