Dealing with Very Large Tables in SQL Server
summary
Practical runbook for tables >1TB with concrete numbers and fixes: an unindexed filter on 20 billion rows, 4.6 TB, 28 minutes, 72M logical reads shows why early indexing matters; use online/resumable builds or filtered indexes if you can. Statistics sampling causes massive overestimates (examples: 100M rows → 44x, specific query 245 vs 32,000 → ~130x); fix with higher sample rates, persist_sample_percent and NORECOMPUTE, or manual filtered stats and async auto‑update. Also demos include profiler checks, columnstore quirks, range‑seek workarounds and ALTER TABLE SWITCH to remove identity without full copy.
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chapters (13)
- 0:00Large tables in SQL Server
- 1:09Defining very large tables
- 3:57Challenges with large tables
- 7:28Missing indexes cost
- 9:57Query writing impact
- 14:10Cardinality estimation issues
- 24:33Fixing cardinality issues
- 28:44Auto update stats async
- 35:38Auto create stats risks
- 39:13Querying log tables
- 42:31Ascending key problem
- 46:18Identity column changes
- 50:33Q&A
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