Rows read per thread show whether a parallel query shares its work evenly. The post shows two plan based methods, a T-SQL query over the last actual plan, and a live DMV for running queries. A 500,000 row demo proves the threads add up to the table.
Unique Index Performance: What a UNIQUE Index Saves
Unique index performance gains come from what the optimizer learns, not from smaller pages. A tested demo compares pages, reads, plans and CPU for a plain index and a unique index. It also shows the error a duplicate causes.
Temp Table Scope in Dynamic SQL: Who Can See What
Temp table scope decides what dynamic SQL and stored procedures can read. Tested demos show a child reading a parent table, a procedure that fails without it, a dynamic table shape and the error a typo causes. A card lists the rules.
Dynamic SQL Temp Table: Why It Disappears and How to Keep It
A dynamic SQL temp table is dropped when its dynamic batch ends, so the main code cannot read it. A global temp table keeps the data, and a per session name keeps it safe. Every step is tested, including the second session clash.
SQL Agent Job Backslash Puzzle: Why Both Rows Were Deleted
A SQL Agent job backslash at the end of a comment line can turn a one row delete into a delete of the whole table. This puzzle sets up the job, explains the cause and tests the effect in T-SQL. It ends with a safe way to write the step.
Disable Resource Governor: Why RECONFIGURE Turns It On
To disable Resource Governor, run ALTER RESOURCE GOVERNOR DISABLE. The post shows why RECONFIGURE enables the feature, with a tested script that restores the state it finds. It also explains how saved pool limits come back to life.
SQL SERVER – Swap Column Values In Table
Here is a question asked to me during Comprehensive Database Performance Health Check. The question was about how to swap column values in a table.