5. Turning on auto-shrink
It might make disk space alerts go away for a minute, but it can cause lots of problems.
4. Enabling xp_cmdshell and giving the SQL Server account administrative rights in Windows
Young DBAs often do this to try to get a quick fix in place to manage backup files. Later on, they realize they can manage all those things in PowerShell or cmd SQL Agent job steps and give more limited permissions. But now they’re not 100% sure of what will break they disable the option and they live in fear of a security audit.
3. Running transaction log backups every 30 minutes, only during the day
“How often should we run these backups?” (Does internet search) “30 minutes seems popular.”
Your backup frequency should be driven by RPO and RTO. And don’t turn them off at night– usually people can still make changes in the system, and there’s no reason to have a giant log backup in the morning.
2. Looking for one magical feature that will fix all performance problems
When you first start out, it seems like all those expensive enterprise features must make everything blazing fast. Later on, you realize that humble things like indexes, memory, and carefully written TSQL are worth all the effort.
1. Being Rude to All the Developers
As a beginner DBA, it’s easy to work long hours, get stressed out, and start to feel like you’re the only one protecting the SQL Server. You start to say “no” a lot. And sometimes you lose your respect for other people.
But you can’t let that keep happening: if you go down that road, it’ll ruin your job. You’ve got to regularly step back, see things from other people’s perspective, and be part of the team.