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DBA-C0053 · Configuration & Tuning

SQL Server Memory Configuration

Read a max server memory sketch: RAM minus an OS reserve, in megabytes. Do not apply it.

Updated 25 October 2026 · How-To

This is an original planning guide. It is not a vendor manual, an official standard, or legal advice. Example addresses use documentation ranges. Review every command before you paste it.

What this hour is for

The calculator subtracts the OS reserve you type from the RAM you type and writes sp_configure for max server memory in megabytes. The sample inputs are a starting point. Leave memory for the operating system.

Do not run RECONFIGURE during the reading. Do not set the value to the whole RAM, and do not set it to zero. One number, on an instance you administer.

192.0.2.10, 198.51.100.0/24, 203.0.113.0/24, and 2001:db8::/32 are documentation. example.com is a documentation name. A sample password is replaced. It is not a password you keep.

The change you can finish

Apply nothing while you are writing the note. When the lab window opens, it is one change on the database named in the ticket. Read the draft, then the database, then decide.

Rollback is the backup, the file, or the snapshot you saved first. You do not invent a rollback after the only copy is gone.

  1. Type RAM and the OS reserve.
  2. Read the megabytes.
  3. Leave room for the OS.
  4. Do not run RECONFIGURE.
  5. Stop.

Mistakes that outlive the statement

SQL Server Memory Configuration goes wrong in a small set of ways. The list is here so the ticket can forbid them before the window.

Decisions to write down

One decision for SQL Server Memory Configuration: Both inputs are written. The number is written. Nothing was applied. And the instance is yours.

Checks before you call it done

Confirm this before you call the change done: RAM is written. The OS reserve is written. The megabytes are written. Nothing was applied. And the instance is yours. If one of those fails, stop.

-- max server memory leaves room for the OS.
-- Do not run RECONFIGURE during the reading.
-- Do not set the value to zero.

Before you leave the database

SQL Server Memory Configuration ends when the database in the prompt is the database in the ticket. If it is not, you are on the wrong database. Stop.

The draft stays a draft until a person has read the names in it. A generator does not log into the database. You delete a line that names a host, a database, or an account you did not write down.

192.0.2.10, 198.51.100.0/24, 203.0.113.0/24, and 2001:db8::/32 are documentation. example.com is a documentation name. They belong in the note. They are not values you leave on a database because a draft included them.

prompt-for-this is a reminder that a secret is missing. It is not a password, a key, or a token you save in the ticket or in git. A sample password in a draft is replaced. It is not a password you keep.

One change is the window. If two things move and the result is wrong, you will not know which one did it.

If the same step fails twice, stop for the day. Restore the copy you took first.

A second person reads the database name and the change aloud. If they cannot find them in the ticket, the note is not done.

This page is a planning guide. It is not a vendor manual, not an official standard, and not permission to touch a database you do not administer. You do not disable authentication, a firewall, or TLS to make a check pass.

Tools for this guide

These tools run in the browser on this site. They do not log into your machines.

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