Blog Posts

What's the best way to massively update a big table?

A thing that can happen once in a while in a DW is the need to massively update a column in a table, let’s find out.

Read More

SQL Server 2017 CU5 enhances troubleshooting for Intra-Query Parallelism Deadlock

Do you remember this post from not long ago ? Apparently, other than still being an issue, with the latest SQL Server 2017 CU there are additional tools to see what’s going on and troubleshoot.

Read More

Test: confronting various methods of bulk loading data from a table to another, what's the fastest?

 Most of the support request I get involved with can be summarized with the following keywords: “slow” + “datawarehouse” + “ETL” + “Save us” What about thinking about ETL performance before it goes bad?

Read More

Can a single query deadlock itself? Apparently, yes: A curious case of Intra-query Parallelism

Imagine that you’re in a SQL data warehouse in the middle of the night, a single stored procedure is running, is nothing else, and it’s simply doing inserts and updates, one statement at the time, but then.

Read More

Scan Performance Showdown: INROW Predicate pushdown VS Batch Mode Adaptive Join vs Columnstore indexes

I was reading Paul White’s post about bitmaps in SQL Server and, other than realizing that I basically know nothing about anything (like a Socrate’s epiphany) I wanted to at least see how this good stuff added up in the latest 7 years.

Read More

Creating a Perfmon and Filestats reports in PowerBI [Part 1]

If you work for a big company, you may have a bunch of instances/databases under your control, you ran whatever monitoring tool has been provided and everybody is happy; But if your’re like me and you’re working for a big number of customers, each one with a different version of SQL and own configuration/security policies, with no monitoring tool directly available, and have to answer the question “what happened to the instance the other night” you may be a little bit overwhelmed.

Read More

How to get and decode callstacks in in extended events for recent versions of SQL Server

The other day I was reading about spinlocks and troubleshooting and it mentioned to get the callstack for a certain xevent and to decode it using the windows debugging symbols, however, that material was related to SQL Server 2012 and the steps weren’t basically replicabile for a modern version like SQL 2016/2017 (or even 2014 I think, but haven’tn checked personally), I searched around and didn’t really find something straight forward for just the process as it is now: So, here we are, small guide on how to get and decode callstacks in recent versions of SQL Server.

Read More

Create an asynchronous multithreaded workflow on your SQL Server using the Service Broker

As any other *Server, SQL Server is born with concurrency in mind, a lot of users/applications can connect concurrently and do their job, as designed, perfect, but, what if you’re the only user?

Read More

THREADPOOL, or, Why is SQL server not responsive even the CPU is basically idle?

It’s a late Friday afternoon, this means that somebody is going to tell you that the server is unresponsive, users are blocked and there is a imperative deadline for the business at 6PM (which you think is probably because they don’t want to be late to the happy hour), so you do what you do best: sigh and log on to see what’s going on with this instance.

Read More

How to avoid the traps when dealing with parallelism

I work with a vendor application which needs to do all sorts of data crunching in some nightly batches, and, depending on the size of data, this process may take a lot of time.

Read More
Categories
Tags