Tag: Query Tuning
-
Parameter Sniffing in SQL Server: A Measured Example, Not Just the Theory
Parameter sniffing is SQL Server doing exactly what it’s supposed to do: compiling a query plan based on the actual parameter value passed in the first time it runs, then reusing that plan for later calls. That’s normally the right behavior, a plan built for the real value is usually better than a generic one.…
Written by
-
Table Variables vs Temp Tables in SQL Server: What the Optimizer Actually Sees
The usual line on table variables vs temp tables is “table variables don’t have statistics, so the optimizer assumes 1 row.” That was true once. It isn’t the whole story on a current SQL Server, and the actual gap between what the optimizer assumes and what’s really there is worth measuring rather than repeating from…
Written by
Blog Categories
- Backups & Recovery (5)
- DBA Scripts (146)
- High Availability (HA) (7)
- Installation & Configuration (16)
- Maintenance (4)
- Migration & Upgrades (1)
- Monitoring (6)
- Performance Tuning (5)
- Security (Encryption & Permissions) (3)
- T-SQL Fundamentals (11)
- Troubleshooting (23)
- Wait Types (235)
Latest Posts
- SQL Server Compatibility Level: What Actually Changes When You Bump It
- SQL Server Management Studio (SSMS): The Complete Guide
- SQL Server Collation: Case Sensitivity and the Cross-Database Trap
- SQL Server Isolation Levels (and When to Reach for RCSI)
- DBA Scripts: Get Database Summary
- DBA Scripts: Get Database Inventory
Blog Tags
Access (3) Always On Availability Groups (4) Auditing (7) Backups (6) Blocking (4) Blocking Locking (6) Collectors (7) Database Backups & Recovery (8) Database Backups and Recovery (5) Database Maintenance (7) DBA Tools (24) Disk Space (5) Extended Events (8) Features (6) High Availability (6) Indexes (7) Installation (7) Instance (3) Inventory (8) Maintenance (7) Migration (15) Monitoring (27) Performance (21) Performance Troubleshooting (9) PowerShell (4) Query Behaviour (5) Security (9) SQL Agent (5) SQL Scripts (17) SQL Server Administration (10) SQL Server Configuration (7) SQL Server Errors (5) SQL Server High Availability (4) SQL Server Internals (3) SQL Server Management Studio (SSMS) (6) SQL Server Monitoring (7) SQL Server Networking (9) SQL Server Security (7) Storage and Capacity (7) T-SQL (10) Temp DB (3) Tracing (7) Transaction Logs (4) Troubleshooting (24) Windows Server (4)