When a query runs slow occasionally, the cause sits around the query: a lock, a job, a file growth, tempdb or a shortage of worker threads. This post gives one tested T-SQL check for each and a small demo for blocking and file growth. It also says what to do when all five checks find nothing.
In-Memory OLTP Migration Checklist: Which Features Block You
An In-Memory OLTP migration checklist from SSMS lists the tables and procedures the engine will refuse. This post tests those refusals on SQL Server 2025, shows which old limits are gone, and adds a query that finds blockers in your own database.
SQL SERVER – Active Parallel Requests and Cached Parallel Query History
I Identify parallel running requests separately from parallel queries recorded in the cache. Those lists answer different performance questions.
Force a Parallel Plan: ENABLE_PARALLEL_PLAN_PREFERENCE Hint
To force a parallel plan for one query, add the ENABLE_PARALLEL_PLAN_PREFERENCE hint to its OPTION clause. This post shows why a cheap query stays serial, runs a demo query with and without the hint, proves the difference from the last actual plan, and explains why the hint belongs in a test and not in every query.
DBCC DBREINDEX: Replace It With ALTER INDEX in SQL Server
DBCC DBREINDEX still runs on SQL Server 2025, but it is deprecated, and ALTER INDEX does everything it did and more. This post rebuilds a fragmented demo table both ways, shows the options only ALTER INDEX has, and finds old uses of DBCC DBREINDEX in your own modules, Agent jobs and the deprecation counter.
Read Heavy Workload or Write Heavy: Measure It in SQL Server
To tell a read heavy workload from a write heavy one, compare what the server reads with what it changes, and measure it over a window. This post counts reads and writes per table, reads the buffer and log counters with two snapshots, and explains what each lens misses.
Actual Execution Plan in SQL Server: Graphical, Text and XML
An actual execution plan shows how SQL Server really ran a query, with the true row counts beside the estimates. This post gets the plan three ways, as a graphical plan, as text with SET STATISTICS PROFILE and as XML, and uses a demo table to show how the estimate and the actual number can disagree.