Press "Enter" to skip to content

Category: Storage

Troubleshooting Azure Synapse Link for SQL Server Issues

Published 2023-04-06 by Kevin Feasel

Kevin Chant diagnoses an issue:

In this post I want to cover common Azure Synapse Link for SQL storage permission issues. Since I helped a fellow MVP out with this recently.

To be more precise, I want to show how you can fix one of the most common issues I tend to encounter with Azure Synapse Link for SQL. Which is access to the Data Lake Storage Gen2 account.

I have encountered issues like this a few times now. For example, when I was performing my file tests for Azure Synapse Link for SQL Server 2022.

Click through to learn more about a couple of common issues, their causes, and resolutions.

Comments closed

Finding Columnstore Index Storage and Memory Allocations

Published 2023-03-31 by Kevin Feasel

Jose Manuel Jurado Diaz has a few scripts for us:

Today, we got a new question how much is the size used by a columnstore index table at storage level and memory usage.

TSQL to obtain the total number of rows, size per schema, table and index.

Using the view sys.column_store_row_groups (Transact-SQL) – SQL Server | Microsoft Learn we could see the total number of rows and space usage at storage level.

Click through for that script, as well as a few more to learn how much space and memory that columnstore index is taking.

Comments closed

Tagging on Pure Storage Volumes

Published 2023-01-27 by Kevin Feasel

Anthony Nocentino tags all the things:

A tag is a key/value pair that can be attached to an object in FlashArray, like a volume or a snapshot. Using tags enables you to attach additional metadata to objects for classification, sorting, and searching. For example, you can assign a tag to a collection of volumes and then come along later and retrieve a listing of volumes that match a particular key or value. You can use tags to add application context to resources inside FlashArray. Specifically, in the examples in this blog post, I want to tag volumes with the names SQL Server Instances.

Click through to see what you’d need to do, assuming you have an appropriate device running Purity 6.0 or later.

Comments closed

The Unimportance of IOPS

Published 2023-01-09 by Kevin Feasel

Kellyn Pot’vin-Gorman explains that there are things more important than IOPS when considering database choices:

IOPs is Overrated, yeah, I said it.

How many compute, storage area networks, hard drive vendors and storage services have posted their IOPs capabilities in marketing and didn’t include the throughput (MPBs)?  Why when someone sends me IOPs for an Oracle database do I thank them kindly and ask for throughput? 

Read on for more. This post is specific to Oracle but the general principle applies to SQL Server and all other relational databases as well.

1 Comment

Hyperconverged Storage and Trace Flags

Published 2022-11-28 by Kevin Feasel

David Klee has a tip for us:

We all (should) know that running SQL Server in hyperconverged virtual environments, both on-premises and in the cloud, has some interesting trade-offs. The biggest is write latency from the hyperconverged storage platform underneath the database. We find that write latency suffers compared to traditional all-flash storage, even if the hyperconverged layer is all-flash as well, due to how the hyperconverged layer handles the larger block write that the SQL Server engine drops on it.

Read on for a trace flag which could help here.

Comments closed

Troubleshooting I/O Issues in SQL Server

Published 2022-11-15 by Kevin Feasel

Ajay Dwivedi shares some advice:

Storage performance is something that puzzles a lot of SQL Server professionals. So in this blog, I will cover the basic steps I perform to ensure I get the best performance from the underlying storage.

Read on for some thoughts on storage testing prior to SQL Server installation, as well as what to do to ensure your SQL Server instance is up and at them.

Comments closed

Storage Snapshots and In-Memory OLTP

Published 2022-10-27 by Kevin Feasel

Andy Yun answers a question:

Can I still take storage-array snapshots and if yes, will I lose data in my memory-optimized tables? What about data inside my non-durable tables?

Thankfully, the question was not in the headline. Therefore, Betteridge’s Law of Headlines does not apply and the answer may be either ‘yes’ or ‘no’ depending on the facts. Speaking of which, to find that answer, click through and read Andy’s post.

Comments closed

SQL Server 2022 and Azure Data Lake Storage

Published 2022-09-12 by Kevin Feasel

I continue a series on data virtualization in SQL Server 2022:

Today’s post is a fairly short one. Let’s say you want to connect to Azure Data Lake Storage Gen2 from SQL Server 2022. We saw in a recent post how to connect to Azure Blob Storage. When it comes to Azure Data Lake Storage, the story is almost the same, though there are a couple pitfalls you will want to avoid.

Read on for that error, which stymied me for a good 10 minutes.

Comments closed

Inserting into Azure Blob Storage from SQL Server 2022

Published 2022-09-09 by Kevin Feasel

I continue a series on data virtualization in SQL Server 2022:

Several years ago, I wrote a blog post on how to insert data into Azure Blob Storage from SQL Server using PolyBase. That technique used PolyBase V1: the Java connector for Hadoop. With SQL Server 2022 eliminating that connector, we’re going to learn the new method.

This is one of the larger practical differences in data virtualization with SQL Server 2022.

Comments closed

Connecting to Azure Blob Storage with SQL Server 2022

Published 2022-09-06 by Kevin Feasel

I take a look back at the past and forward to the future:

PolyBase used to connect to Azure Blob Storage. Specifically, you could use the wasbs:// protocol and connect to Azure Blob Storage over WebHDFS. Here’s an example of an external data source which would work for SQL Server 2016 through 2019:

SQL Server 2022 changes its mechanisms around Azure Blob Storage a little bit, though I think the changes are sensible.

Comments closed