I’ve had a couple of months at home, focusing on consulting engagements, and now I’m about to enter back in to conference / Immersion Event season. I’ll still be consulting, but half of the time I’ll be doing it from a hotel room. While it is nice to interact with people via email, phone and […]
Joe Sack
SQL Server Performance Tuning, High Availability and Disaster Recovery Blog
SQL Server Event Schedule for H1 2013
Posted on: January 31, 2013 4:36 am
Auto-Update Stats Default Sampling Test
Posted on: January 15, 2013 3:16 pm
In this post I’ll just share the results of a simple set of tests regarding automatic-update sampling. Nothing fancy – I just populated the category table from the Credit sample database with varying row counts and then took note of the associated duration and sampling percent. The query I used to kick of auto-updates after […]
New Course: “SQL Server: Troubleshooting Query Plan Quality Issues”
Posted on: January 11, 2013 5:14 pm
My latest online course, “SQL Server: Troubleshooting Query Plan Quality Issues” was published today by Pluralsight. The short description is as follows… “Learn how to identify, diagnose, and prevent problems where SQL Server chooses the incorrect query plan for your critical queries, applicable to developers, DBAs, and anyone responsible for SQL Server, from SQL Server 2005 onwards.” This 2 […]
Detecting Selectivity Guesses
Posted on: January 10, 2013 3:16 pm
I’ve been mulling over a potential Microsoft Connect item regarding selectivity guess warnings, but I’m uncertain if it would have enough demand to drive product team attention. Selectivity guesses, which I talked a little about in the “Selectivity Guesses in absence of Statistics” post, are sometimes referred to as “magic numbers”, “heuristics” or just plain […]
Row and Page Count Influence on Sort Memory Grants
Posted on: January 9, 2013 4:07 pm
My prior post demonstrated the influence of row and page counts on estimated CPU and I/O cost. Now in this post I’m going to step through the influence of row and page counts on memory grants for a Sort operator. I’ll be using the MemoryGrantInfo element from the query execution plan to measure the influence. I […]
Row and Page Count Influence on Estimated CPU and I/O Cost
Posted on: January 8, 2013 1:12 pm
In this post I’ll step through a few scenarios regarding row and page counts – and their associated influence on estimated CPU and I/O cost. I’ll be using the Credit database to demonstrate different scenarios… Starting State I’ll start off by checking the total number of reported data pages and row counts for the member […]
