“SQL Server Is Slow”

How should you respond when you get the dreaded Email/Slack/Text/DriveBy from someone yelling at you that SQL Server is slow?

Stop. Don’t Open SSMS Yet.

You’ve heard it before: “The server is slow.”

What does that actually mean?

If you jump straight into SQL Server looking for blocking, bad queries, or a missing index, you’re working with bad input. And bad input = wasted time.

The real work starts before you ever connect to SQL Server.

Intake & Scoping Comes First

Your first job is to turn “slow” into something measurable and time-bound. That means gathering evidence, building a timeline, and classifying the type of incident.

Translate “Slow” Into Scenarios

“Slow” can mean very different things depending on who you ask:

• Login delays - Applications take 30 seconds to connect.

• Application lag - a report that usually runs in 2 seconds now takes 30.

• Broad latency - all users complain at once.

• Maintenance overruns - ETL jobs not finishing in their normal window.

• Timeouts or errors - not just lag, but outright failures.

Each one can lead you in a different direction.

The Fast Intake Questionnaire

Ask these every single time:

1. What exactly was slow? (screen/report/job/login)

2. When did it start? (date/time, not “earlier today”)

3. How widespread? (one user, team, region, everyone)

4. Repeatable? (every time, sometimes, once)

5. What changed? (deploys, patches, config, new data)

6. Is it happening now? (yes/no)

7. Evidence (screenshots, error messages, job names with timestamps)

Classify the Incident

Once you have real answers, put it in a bucket:

• Happening now - live triage needed.

• Recurring/pattern - happens on a schedule.

• Sporadic - random spikes.

• One-time - tied to a patch, deploy, or outage.

Build the Timeline

Anchor events with real timestamps.

• “Around lunch” = useless.

• “9:12 AM CST, FinanceApp login timeout” = actionable.

Capture start, stop, duration, who was affected, and what else was happening on the system at that time.

The (first) Bottom Line:

Action without information is useless. Any other service provider (ER doc, plumber, electrician, auto mechanic) will ALWAYS triage your issues before starting an investigation or fix. You should too.

Are you ready for a REAL database disaster?

Take the quiz to find out:

SQL Server Recovery Assessment | 2-Minute Quiz

SQL Tidbit:

When gathering timelines, align your clocks. SQL Server may log in UTC while users report in Central or Eastern time. A “9 AM slowdown” can easily show up in SQL logs at 2 PM. Get this wrong and you’ll chase the wrong evidence.

Link Party

Deprecated but Forgotten: Why SQL Server’s Text, NText, and Image Data Types Still Haunt Your Systems
A detailed exploration of why legacy data types like TEXT, NTEXT, and IMAGE are problematic and how migrating to VARCHAR(MAX), NVARCHAR(MAX), or VARBINARY(MAX) can dramatically improve performance and compatibility.

 Connect Cloud Power BI to on‑prem SQL Server
A helpful step-by-step guide (published on September 2, 2025) walking you through installing the Power BI Gateway, configurations, and how to keep on-prem SQL Server datasets up to date in the cloud.

Announcing SQL Server 2025 Release Candidate 0 (RC0)
The official Microsoft announcement—released on August 22, 2025—introduces RC0 and highlights the new PREVIEW_FEATURES database-scoped option enabling opt‑in access to cutting-edge developments.

SQL Server 2025 Preview: Now Supporting Ubuntu 24.04 and TLS 1.3
Published August 21, 2025, this announcement covers the exciting new support for Ubuntu 24.04 (for dev/test workloads) and default enablement of TLS 1.3 in SQL Server 2025 RC0.

SQL Server 2025 RC0 Is Out with New Preview Features
A friendly commentary by Brent Ozar (August 26, 2025) summarizing key RC0 features—including PREVIEW_FEATURES, Change Event Streaming, vector indexes, and AI-related capabilities—great for quick insights.

Please share with your friend that starts tuning queries when someone has an open query: Select everything from everywhere…