A Fine Slice Of SQL Server
Erik Darling reminds you to check out the properties of execution plan elements:
I read a lot of posts about query plans, and I rarely see people bring up the properties tab.
And I get it. The F4 button is right next to the F5 button. If you hit the wrong one, you might ruin everything.
But hear me out, dear reader. I care about you. I want your query plan reading experience to be better.
Erik provides sound advice here.
Comments closedSamir Behara takes us through troubleshooting AWS Database Migration Service issues:
For troubleshooting any issues with AWS DMS, it is necessary to have logs enabled. The DMS logs would typically give a better picture and helps find errors or warnings that would indicate the root cause of the failure. If the logs are not available there is nothing much you can do from a detailed troubleshooting analysis perspective. So basically next step is to turn on DMS logs and kick the job again and validate if the errors are captured in the logs.
If logs are not enabled, you need to set up a new task with logging enabled so if and when it errors out, you can take a look and troubleshoot the same.
I’ll save my full rant for another day, but I’m not that impressed with DMS. It could be a failing on my part, though.
Comments closedBub Pusateri has a helpful script for us:
Last year I wrote about how to upload data to Azure Blob Storage Archive Tier, and included a PowerShell script to do so. It’s something I use regularly, as I have hundreds of gigabytes of photos and videos safely (and cheaply!) stored in Azure Blob Storage using Archive Tier.
But read on for a recent announcement to make the process easier.
Comments closedArun Sirpal explains what an Azure Shared Access Signature is:
Using a Shared Access Signature (SAS) is usually the best way to control access rights to Azure storage resources (like a container for backups) without exposing the primary / secondary storage keys. It is based on a URI and this is what I want to look at today.
Read on to learn about the components which make up a Shared Access Signature.
Comments closedI presumed the graph would depict cancellation rates for a set of products, with “Tier 2 with Promotion” at the top, representing the highest cancellation rate. When we get to the data, though, that’s not the case. Rather, the graph shows the inverse metric (retention rate) with Tier 2 + Promo as the bottom line with the lowest retention rate. Eventually I figured this out—but only because I spent time studying the data to make this determination!
Click through for the initial visual as well as a couple of alternatives.
Comments closedJohn Mount takes us through a couple of data shaping packages:
The advantages of data_algebra and cdata are:
– The user specifies their desired transform declaratively by example and in data. What one does is: work an example, and then write down what you want (we have a tutorial on this here).
– The transform systems can print what a transform is going to do. This makes reasoning about data transforms much easier.
– The transforms, as they themselves are written as data, can be easily shared between systems (such as R and Python).
Let’s re-work a small R cdata example, using the Python package data_algebra.
Click through for the example.
Comments closedAndy Levy wraps up a Q&A series on dealing with thousands of databases:
When you started, did you know what your position was going to look like 1 month, 6 months, 1 year, 5 years from then? How accurate has that been so far?
I’ve only been at my current job for about 2 1/2 years, but I can speak to the shorter intervals. I’m going to be intentionally vague in spots here as I don’t want to disclose too much.
And if you’d like to hear Andy talk about migrating 8000 databases, Carlos Chacon and I interviewed Andy for the SQL Data Partners podcast.
Comments closedJohn Sterrett has run into a few issues with Azure Backup for SQL Server VMs:
Having the ability to backup new databases automatically is taken for granted. So much, that I noticed that Azure Backup for SQL Server VM’s will not automatically backup new databases for you. That’s right. Make sure you remember to go in and detect and select your new database every time you add a database or you will not be able to recover.
Azure Backup for SQL Server VM’s has an interesting feature called Autoprotect. This should automatically backup all your databases for you. Unfortunately, this does not work. Yes, I double-checked by enabling autoprotect for a VM and I added a new database. The database didn’t get backed up so I had to manually add the database.
Some of these seems like it’s easy enough to fix, so hopefully the product gets better over time.
Comments closedDavid Eldersveld shows how you can use orthographic projection in Power BI:
The projection from three coordinates to a 2D plane is achieved by adding the following two measures. Be sure to adjust the column references and what-if parameter names at the top to correspond to your own data.
Here’s my “Ortho x” measure. The initial six bold values are what you’d need to adjust to your own data and parameter names.
David lays out a face, which is pretty neat.
Comments closedMala Mahadevan continues a series on graph tables in SQL Server:
I have highlighted in red what SQL Server adds to the table – the two system columns – graph id, which is bigint, and node id, which is nvarchar and stores json, and the unique index to help with queries.
We can also see from constraint type that this table is similar to other relational tables – it can be enabled for replication and can have related delete or update actions defined on it if need be.
This post gives a bit more insight into how graph tables work in SQL Server under the covers.
Comments closed