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Category: Administration

Exporting SQL Server Configurations

Published 2020-11-11 by Kevin Feasel

Garry Bargsley shows how you can export configuration settings for your SQL Server instances:

Have you ever deleted a login by mistake from a hastily typed TSQL script or dropped a list of logins because the “Business” said they are not used anymore? Have you ever made a change to a SQL Server Agent job and then it failed on the next execution. What about that time you changed the Database Mail profile on all of your servers and left your personal account in the script instead of the DBA distribution list.

While each of these examples is not life-threatening, they will strike fear in you depending on how prepared you are to recover the items in question.

This is the type of thing you’d want to store in source control, too. That way, you have a record of changes over time.

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An Intro to Backup Strategy with SQL Server

Published 2020-11-10 by Kevin Feasel

Pamela Mooney takes us through backup and restoration as part of a DBA in training series:

A DBA’s job is getting the right data to the right people as quickly as possible.

Consider that first part – getting the right data. How do you do that? By having the data in the first place. The best way to ensure that you have the data is to look at your company’s needs, recommend availability options, and most importantly, do backups. Few things will get a DBA fired more quickly than not having backups available when they are needed. It may be years before you ever have to restore a database from a backup, but the backups had better be there when you need to do one.

Conference sessions and books have been written on the subjects of backup/restores, SLAs, and availability options, and they are so good that I’ll just give you a brief overview here. You’ll gravitate to your need-to-learns soon enough.

This is a nice overview for a beginner. One semi-related piece of advice that I picked up from Sean McCown: know that backup and restore syntax cold. Take backups manually (even if they’re just on a test server intended for this purpose) every day until you feel comfortable typing out backup and restore syntax from memory. There will come a time when three levels of management are standing over your shoulder waiting for a database to restore and SSMS’s GUI is crawling. At that point, knowing the syntax cold will be completely worthwhile.

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Accelerated Database Recovery in SQL Server 2019

Published 2020-11-10 by Kevin Feasel

Jamie Wick walks us through the key concepts with Accelerated Database Recovery:

Beginning with SQL Server 2019, Microsoft has redesigned the database recovery process (ie. crash recovery and rollback) to improve availability and performance. This new feature is called Accelerated Database Recovery (ADR).

Prior to SQL Server 2019, recovering a database (after a crash or restart) consisted of 3 phases that followed the ARIES (Algorithm for Recovery and Isolation Exploiting Semantics) recovery model. The phases of this model are Analysis, Redo & Undo. The Analysis phase begins with the last successful database checkpoint and forward-scans the transaction log to determine the state of each transaction. The Redo phase begins with the oldest uncommitted transaction (that was active after the checkpoint) and rolls-forward, bringing the database state to the same point it was at immediately prior to the crash. The Undo phase then goes backward from the end of the transaction log to reverse all transactions that were active (uncommitted) at the time of the crash. With this process, the database recovery time is roughly the same as the longest running query that was active at the time of the crash.

Click through for the full story.

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DBCC CHECKDB on Large Databases

Published 2020-11-06 by Kevin Feasel

Aaron Bertrand shares some thoughts on CHECKDB:

We have a lot of data. Some of that data is stored in large databases (dozens of terabytes each). In some shops, this is an excuse to not run integrity checks. We are not one of those shops.

But we don’t run full CHECKDB operations in production; we have a set of servers dedicated to testing our restores and running checks. We follow a lot of the guidance in these articles:

– CHECKDB From Every Angle: Consistency Checking Options for a VLDB

– Minimizing the impact of DBCC CHECKDB : DOs and DON’Ts

– Minimize performance impact of SQL Server DBCC CHECKDB

Read the whole thing, even if you aren’t dealing with 30+ TB databases.

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Creating Users in Azure SQL Database

Published 2020-11-06 by Kevin Feasel

Kenneth Fisher takes us through a nuance in adding users to Azure SQL Database:

Awesome! I did say I preferred code didn’t I? I am noticing a slight problem though. I don’t actually have a login yet. So I look in object explorer and there is no instance level security tab. On top of that when I try to create a login with code I get the following error:

Msg 5001, Level 16, State 2, Line 1
User must be in the master database.

Read on for the whole process.

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A Primer on Multi-Server SQL Agent Administration

Published 2020-11-05 by Kevin Feasel

Mikey Bronowski gives us a glimpse at the power of MSX/TSX:

The MSX (master server) can be used to define SQL Agent jobs that then will be pushed over to one or more TSX (target servers). It is possible to see the server is either MSX or TSX when looking at SQL Agent in SQL Server Management Studio Object Explorer. The master server can be identified by (MSX) next to the SQL Server Agent. It will also have two subfolders under the Job folder: Local Jobs (for regular jobs) and Multi-Server Jobs.

This is something woefully few database administrators take advantage of. As the number of servers you have to mange increases, ensuring consistency in SQL Agent jobs becomes more and more difficult. MSX/TSX admittedly has some rough edges, but the tool does a lot.

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FAIL_PAGE_ALLOCATION in SQL Server

Published 2020-11-04 by Kevin Feasel

Eric Cobb diagnoses an ugly issue:

I recently ran into a situation where a new SQL Server would crash hard every time it would get under a load.

Here is a synopsis of what we were seeing:

This is a physical server and has 512GB of RAM installed. We have SQL Server 2016 installed, and fully patched (SP2 CU15 at this time). When load testing the server, it would start throwing errors such as:

“Failed allocate pages: FAIL_PAGE_ALLOCATION”

and

“There is insufficient system memory in resource pool ‘default’ to run this query.”

and

“Failed to allocate BUFs”

It would then write a memory dump to the log, and in most cases the server would become completely unresponsive and would have to be rebooted.

Read on to learn under what conditions this happens as well as the solution to the problem.

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Considerations Before using SQL Server on Containers

Published 2020-11-04 by Kevin Feasel

Joy George Kunjikkur wants you to slow your roll a little:

It is easy to get started on development and simple testing using SQL containers. It was discussed in the previous post. But before putting into production and start developing real applications we had to make sure the below things at least.

Read on for those considerations. I think they are reasonable and generally agree with the bottom-line conclusion.

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Query Processor Ran Out of Internal Resources

Published 2020-11-02 by Kevin Feasel

Andy Galbraith troubleshoots a problem:

 Unfortunately a common error in many of our client environments is this:

—

Error: 8623, Severity: 16, State: 1.

The query processor ran out of internal resources and could not produce a query plan. This is a rare event and only expected for extremely complex queries or queries that reference a very large number of tables or partitions. Please simplify the query. If you believe you have received this message in error, contact Customer Support Services for more information.–There are many potential causes for this, and the text of this particular error is very well-written because the primary cause is exactly what is listed – a complex query.

Read on to see how to find this complex query, as well as a few examples of complex queries.

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