Here at Brent Ozar Unlimited We have a proud tradition of not blaming index fragmentation for everything. There are points you should deal with it, but they're probably not 5% and 30% and 1000 pages. But that's not what this blog post is about. I'm hoping to clarify why we're more interested in up to…
Getting developers production data stinks DBAs are stuck in this annoying cycle where they need to give developers production, or production-like data, but... Production data can be huge. Hundreds of gigabytes if you're lucky, several terabytes if you're not. Then once it gets there, you have other considerations. Either you lock down Dev, or you…
In celebration of AdventureWorks being out of business for a decade
Microsoft has released a couple new databases. Wide World Importers is a fresh-faced start up, probably a drug smuggling front, run out of a basement office next to a temp agency.
There's some JSON involved. No one ordered bikes. It's a hoot.
To follow up on my NY Times Best Selling blog post
On First Day Deal Breakers, here's something you can do on your last day, as a friendly reminder that everyone is losing a valued team member.
Change the color of everyone's error messages.
I'll get right to the point While you're Direct Seeding, you have to be careful with any other full or differential backup jobs running on the server. This is an artifact of the Direct Seeding process, but it's one you should be aware of up front. In the screencap below, courtesy of sp_whoisactive there's a…
Note: THERE ARE BUGS IN THIS FEATURE. Make sure you read all the way through the post to catch the updates from Microsoft as more bugs were found.
TDE is one of those things!
You either need it, and quickly learn how many things it plays the devil with, or you don't need it, and there but for the grace of God go you. Off you go, with your compressed backups, your instant file initialization, your simple restore processes. Sod off, junior.
From the Mailbag In another post I did on Direct Seeding, reader Bryan Aubuchon asked if it plays nicely with TDE. I'll be honest with you, TDE is one of the last things I test interoperability with. It's annoying that it breaks Instant File Initialization, and mucks up backup compression. But I totally get the…
As of this writing, this is all undocumented
I'm super interested in this feature, so that won't deter me too much. There have been a number of questions since Availability Groups became a thing about how to automate adding new databases. All of the solutions were kind of awkward scripts to backup, restore, join, blah blah blah. This feature aims to make that a thing of the past.
This post covers two scenarios
You either created a database, and the sync failed for some reason, or a database stopped syncing. Our setup focuses on one where sync breaks immediately, because whatever it's my blog post. In order to do that, I set up a script to create a bunch of databases, hoping that one of them would fail. Lucky me, two did! So let's fix them.
Normally I'd update the original post But I wanted to add a bit more than was appropriate. For my interview question, I asked how you'd respond to a developer showing you progress they'd made on tuning a sometimes slow stored procedure. While a lot of you gave technically correct answers about the recompile hint, and…
We love to help people plan for disasters
We're not pessimists, we've just seen one too many servers go belly up in the middle of the night to think that having only one is a good idea. When people ask us to help them, we have to take a lot into consideration. The first words out of the gate are almost always "we've been thinking about Availability Groups", or some bastardized acronym thereof.
One of my least favorite things about Availability Groups
Well, really, this goes for Mirroring and Log Shipping, too. Don't think you're special just because you don't have a half dozen patches and bug fixes per CU. Hah. Showed you!
Brent's in class this week!
So you get me instead. You can just pretend I'm Brent, or that you're Brent, or that we're both Brent, or even that we're all just infinite recursive Brents within Brents. I don't care.
Here's the setup
A new developer has been troubleshooting a sometimes-slow stored procedure, and wants you to review their progress so far. Tell me what could go wrong here.
This is not a deep dive
If you're looking for lots of internals and explanations of what happens behind the scenes, don't read past here. I almost made a READPAST joke. It's that kind of day. This is just a basic overview of creating some indexes and gathering statistics. Why? Because someone just paid about $47.5k for every 0.75 cores of Oracle Enterprise licensing and they probably expect some performance out of it. This isn't MySQL. We don't have all day to get query results.
We're not so different, you and I
In any database platform, you'll have to deal with NULLs. They're basically inescapable, even if you own an island. So let's compare some of the ways they're handled between Oracle and SQL Server.
Twofer
If you take a look at the two queries below, there are a couple things going on. First is the NVL function. It's basically the equivalent of SQL Server's ISNULL function, where it will return the second argument if the first is, well, NULL.
I probably should have written this one first Most of these are exactly the same as in SQL Server. There are a whole bunch of interesting analytic functions, most of which should look pretty familiar to anyone who has spent time querying SQL Server. Most, if not all, can be extended to be window functions,…
Oh, THAT relational data
Thankfully, most major platforms (mostly) follow the ANSI Standard when it comes to joins. However, not all things are created equal. Oracle didn't have CROSS and OUTER APPLY until 12c, and I'd reckon they're only implemented to make porting over from MS easier. It also introduced the LATERAL join at the same time, which does round about the same thing.
Bake your own cake
Pre-cooked example databases are cool for a lot of things. The first being that everyone can have access to them, so they can follow along with your demos without building tables or inserting a bunch of data. If you mess something up, it's easy to restore a copy. The main problem is that they were usually designed by someone who didn't have your issues.
Let's start with definitions
Many SANs have caching built in. What kind of cache is important, because if you're dealing with non-SSD storage underneath, you could be waiting for a really long time for it to respond.
Let's start with some definitions of the most popular caching mechanisms available for SANs. I'm not going to say 'only', because some vendor out there might have some proprietary stuff going on that I haven't heard of.
Starting a new job can be scary
If you're not already established in your field, don't know the company all that well, or taking on a role with a higher level of responsibility, it's totally okay if you start drinking in the parking lot. Just kidding! Start drinking at home, that gives you more time to drink and bet on horses. Lifehack!
