15Jul 2014 by Grant Fritchey 2 Comments

Execution Plan Details

PASS, SQL Server, T-SQL
I wouldn't say it's common knowledge that you should look at execution plans when tuning queries, but it's not exactly uncommon knowledge either. But, people tend to get focused on just looking at the graphical part of the plan and there's just not enough information there. Let's take a look at a query: SELECT pc.Name, ps.Name, v.Name, pr.ReviewerName, p.Name, v.ModifiedDate, p.Color FROM Production.Product AS p LEFT JOIN Production.ProductReview AS pr ON pr.ProductID = p.ProductID JOIN Production.ProductSubcategory AS ps ON p.ProductSubcategoryID = ps.ProductSubcategoryID JOIN Production.ProductCategory AS pc ON pc.ProductCategoryID = ps.ProductCategoryID JOIN Purchasing.ProductVendor AS pv JOIN Purchasing.Vendor AS v ON v.BusinessEntityID = pv.BusinessEntityID ON pv.ProductID = p.ProductID WHERE v.ModifiedDate = '2006-02-17 00:00:00.000' AND p.Color LIKE 'Y%'; This generates an execution plan that looks like this: Neither v.ModifiedDate nor p.Color have indexes.…
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11Jul 2014 by Grant Fritchey No Comments

Speaker of the Month, July 2014

Professional Development
Another month another bunch of great presentations. I almost don't want to do this any more. It's hard. I sit through a presentation and I think, "Well, here's the winner this month." Then I go to another presentation and I think, "Well, fudge, now one of these people loses." Then I go to a third and I'm simply blown away. And now I have to pick. Well, it's hard. So let me do this, I'm going to declare two winners this month, but only review one of them. Hey, my blog, my rules. First, I want to award speaker of the month for July 2014 to Wayne Sheffield(b|t) and his presentation Table Variables and Temp Tables that I saw at SQL Saturday 294. What's my measure? That I learned stuff…
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08Jul 2014 by Grant Fritchey 5 Comments

Worst Day of a DBAs Life

Professional Development, Redgate Software
Red Gate Software is running a campaign around coping with the worst day of a DBAs life. We've been posting some really fun stories with, I hope, a kernel of useful information inside each. Chances are, if your DBA career has been like mine, your worst days don't involve explosions and car chases. But now they're asking for people to write up stories, what was the worst day in your life as a DBA. I know, I know, first world problems, right? Regardless, I have yet to put a company out of business or kill anyone with any errors I've made, although I've worked at places where either was possible. But the one day that just stands out, well it started about three weeks ahead of the bad day. I…
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03Jul 2014 by Grant Fritchey 9 Comments

Reflections on the 2014 PASS Summit Selection Process

PASS, Professional Development
Oh we are a bunch of high school kids at heart. Maybe high school never ends (and there's a nightmare, god I hated high school). But, there's been drama about the 2014 PASS Summit sessions and the Selection Committee's work. I was on the committee. I worked as a part of the team responsible for rating sessions for the Azure track (said track is gone, more on that later). As self-serving a statement as this is, I think we did a good job. Further, I think the process worked. You can read the official explanation of the process here. Amy did great work and deserves your thanks. All the volunteers who reviewed over 900 submissions from more than 300 people, ON THEIR OWN TIME, FOR FREE, also deserve your thanks. The vitriol directed at…
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02Jul 2014 by Grant Fritchey 5 Comments

Statistics and Natively Compiled Procedures

T-SQL
Statistics are one of the single most important driving factors for the behavior of the query optimizer. The cardinality estimates stored within the statistics drive costing and costing drives the decision making of the optimizer. So, how does this work with the new SQL Server 2014 natively compiled procedures? Differently. In-memory tables do not maintain their statistics automatically. Further, you can't run DBCC SHOW_STATISTICS to get information about those statistics, so you can't tell if they're out of date or not or what the distribution of the data is within them. So, if I create some memory optimized tables, skip loading any data into them and then run this standard query: SELECT a.AddressLine1, a.City, a.PostalCode, sp.Name AS StateProvinceName, cr.Name AS CountryName FROM dbo.Address AS a JOIN dbo.StateProvince AS sp ON sp.StateProvinceID =…
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30Jun 2014 by Grant Fritchey 11 Comments

The Curse of Working With A DBA

DevOps, Professional Development
I no more than finished my rant from last week than I started thinking about all the reasons why a healthy chunk of the reasons that developers want to bypass relational database is not the horror of the relational database itself, although, that's there. No, a very large reason why is the DBA. We're on a blog called The Scary DBA. I earned that title, well sometimes. Sometimes I got it and I wasn't sure why. However, it's perfectly in keeping with how many people view their database administrators; grumpy, obstructionist, slow, difficult, control freak, etc.. There are even jokes about it, "What's the DBAs favorite word? No!" And for those answering "It depends" that's two words. I understand why. In large part it's that phone in your pocket (used…
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26Jun 2014 by Grant Fritchey 25 Comments

Passion

PASS
I know I tend to be overly passionate. It's something that has gotten me into trouble in the past. It's also probably a huge factor in the things I've been able to accomplish in life. I'm bringing it up at this time because I think passion is causing some conflict within the community around the Professional Association for SQL Server (PASS). On the 25th of June just past the announcements went out for the sessions accepted at the PASS Summit 2014. I found this stressful and exciting two ways. First, and for me personally, most importantly, because I had submitted several sessions and I desperately wanted to speak at the PASS Summit (I've spoken there every year since 2008 and I've made the Top 10 sessions two years in a row,…
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25Jun 2014 by Grant Fritchey 2 Comments

The Utility of Execution Plans in Natively Compiled Procedures

T-SQL
I'm actually having problems identifying the utility of execution plans when working with natively compiled procedures. Or, put another way, why bother? I've posted a couple of times on natively compiled procedures and SQL Server execution plans. I've found the differences interesting and enlightening, but I'm seriously questioning why I should bother, at least currently. I'm sure there will be many changes to the behaviors of the natively compiled procedures and their relationship with execution plans. But right now, well, let's look at an example. I have three simple tables stored in-memory. Here's the definition of one: CREATE TABLE dbo.Address ( AddressID INT IDENTITY(1, 1) NOT NULL PRIMARY KEY NONCLUSTERED HASH WITH (BUCKET_COUNT = 50000), AddressLine1 NVARCHAR(60) NOT NULL, AddressLine2 NVARCHAR(60) NULL, City NVARCHAR(30) COLLATE Latin1_General_100_BIN2 NOT NULL, StateProvinceID INT…
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18Jun 2014 by Grant Fritchey 12 Comments

The Curse of Relational Databases

Professional Development
Let's face it, none of Information Technology is easy. Oh yeah, there are those few geniuses that have an absolute grasp over some small aspect of the stack, or those other geniuses that have a very shallow knowledge level, but understand the entire stack. But the stack itself, it's vast, deep, wide, utterly unfathomable. So what do you do? You cheat. You take shortcuts. You ignore things you don't like/understand/appreciate. And then there's all the things you just don't know. Or, you cheat another way, you get experts that have drilled down on a particular technology so that they'll provide you with the knowledge you need. Ah, but then you have to listen to them and what happens when your local genius (deep or wide) doesn't agree with your hired…
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17Jun 2014 by Grant Fritchey 2 Comments

Natively Compiled Procedures and Bad Execution Plans

Uncategorized
I've been exploring how natively compiled procedures are portrayed within execution plans. There have been two previous posts on the topic, the first discussing the differences in the first operator, the second discussing the differences everywhere else. Now, I'm really interested in generating bad execution plans. But, the interesting thing, I wasn't able to, or, rather, I couldn't see evidence of plans changing based on silly things I did to my queries and data. To start with, here's a query: CREATE PROC [dbo].[AddressDetails] @City NVARCHAR(30) WITH NATIVE_COMPILATION, SCHEMABINDING, EXECUTE AS OWNER AS BEGIN ATOMIC WITH (TRANSACTION ISOLATION LEVEL = SNAPSHOT, LANGUAGE = N'us_english') SELECT a.AddressLine1, a.City, a.PostalCode, sp.Name AS StateProvinceName, cr.Name AS CountryName FROM dbo.Address AS a JOIN dbo.StateProvince AS sp ON sp.StateProvinceID = a.StateProvinceID JOIN dbo.CountryRegion AS cr ON…
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