Backup and Recovery

My Favorite System Column: LOG_REUSE_WAIT_DESC

Hidden away in master.sys.databases is one of the coolest diagnostic tools you might ever need: Transact-SQL SELECT name, log_reuse_wait_desc FROM sys.databases; 1 SELECT name, log_reuse_wait_desc FROM sys.databases; This spiffy little snippet will tell you why each database’s log file isn’t clearing out. Possible reasons include: Log backup needs to be run (or if you could…
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Why RPO and RTO Are Actually Performance Metrics Too

Most companies come to us saying, “The SQL Server isn’t fast enough. Help us make it go faster.” They’re kinda surprised when one of the first things we fill out together is a variation of our High Availability and Disaster Recovery Planning Worksheet: Download the full PDF in our First Responder Kit They say things like, “Wait,…
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Synchronous Always On Availability Groups Is Not Zero Data Loss

In theory, when you configure AlwaysOn Availability Groups with synchronous replication between multiple replicas, you won’t lose data. When any transaction is committed, it’s saved across multiple replicas. That’s the way it works, right? I mean, except when you restart your synchronous replicas, or patch them, or they just stop working for any number of reasons.…
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How to Configure Always On AG Backups with Ola Hallengren’s Scripts

With SQL Server AlwaysOn Availability Groups, you can offload backups to a replica rather than running them on the primary. Here’s how to do it: 1. Install Ola Hallengren’s utility scripts on all of the replicas. During the install, it creates a laundry list of SQL Agent jobs, but doesn’t set up schedules for any of them.…
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How Many Databases Can I Put on One SQL Server?

I’ve seen servers with thousands of databases on a single SQL Server, and it works. Sure, opening the databases list in SQL Server Management Studio is painful, and a lot of third party monitoring tools fall over, but it’s not so bad once you know how to work around these issues. But there’s two issues…
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