Pictures in a database are easy to insert and easy to regret. Here is where the bytes go and how to choose a storage method.
Operator Cost Percentages Are Estimates: Read Actual Time Instead
Read operator cost percentages as estimates, then use actual rows, elapsed time, IO, and repeated work to find the real bottleneck.
Leading Wildcard LIKE Searches: Why They Scan and What Helps
Diagnose a leading wildcard LIKE scan and compare prefix search, reversed suffix keys, full-text search, and n-gram indexing.
Five DMVs Worth Memorizing
Five DMVs worth memorizing show SQL Server sessions, active requests, waits, index use, and file I/O during an incident.
Comparing Two Wait Stats Snapshots to See What Changed
Compare wait stats snapshots over a chosen window, subtract cumulative counters, remove background waits, and calculate rates and average waits.
Nullable NOT IN: Read the Row Count Spool Carefully
Nullable NOT IN needs a clear rule for unknown identifiers. Compare NULL and empty-set results before changing the query or interpreting a Row Count Spool.
Seeing What Is Running Right Now
See what is running right now in SQL Server with request DMVs, statement text, plans, waits, and blocking details in one reusable query.