The Bit Bucket

I’ve run into a situation at a number of sites where the following occurs

• An excessive number of logical page reads during query execution
• Changes have occurred from ntext, text, or image data types have been replaced by nvarchar(max), varchar(max), or varbinary(max) data types, as part of a clean-up of deprecated data types.
• Rebuilding the table greatly reduces the number of page reads and the customer is puzzled about why.

One of the causes for this situation is related to how the data in these columns is stored. The ntext, text, and image data types defaulted to having their data stored out of row. The row contained a pointer to where the data was located. By comparison, the nvarchar(max), varchar(max), and varbinary(max) data types default to storing data in-row where possible.

2014-11-17

OK, been doing a bunch of MVA courses as part of the local Microsoft AU dev div heroes campaign. I need to find 5 Australian citizens who have done at least one of the courses below, and get their email addresses.

You don’t have to do the whole of any badge. For example, you could do SQL Server 1, SQL Server 2, or SQL Server 3.

Anyone up for it? Or do all of the ones for a badge for a figurine. They are cute. There are some t-shirts on offer too.

2014-11-16

Lots of big changes for Visual Studio and .NET were announced today.

The biggest items are:

• .NET becoming open source
• Microsoft work to help move .NET onto Linux and Mac
• Visual Studio 2013 Community Edition
• Visual Studio 2015 Preview available
• Lots of integration for Xamarin developers including Xamarin install from within Visual Studio

The one that I like most here is the Visual Studio 2013 Community Edition. We’ve had Visual Studio Express for some time but it was very limited. In particular, it blocked any attempt to extend it with plug-ins. Plug-ins are where the real creativity with the product can appear. The new community edition is full-featured and free for all except enterprise application development.

2014-11-13

Looking forward to delivering another session for the Perth SQL Server user group. Will be the night of 27th November. Here’s the session details:

“Understanding SQL Server High Availability Options

While more and more systems need ever increasing levels of availability, many customers are confused about when to use each of the high availability options provided by SQL Server. In this session, Greg will provide a detailed overview of log shipping, database mirroring, failover clustering and availability groups, with recommendations on where and when to use each, and the pros and cons of each option. He will discuss all currently-supported versions of SQL Server from 2008 to 2014. If you are confused about SQL Server HA options, this session is for you.”

2014-11-13

I’m not a fan of letting the system automatically name constraints, so that always leads me to thinking about what names I really want to use. System-generated names aren’t very helpful.

Primary keys are easy. There is a pretty much unwritten rule that SQL Server people mostly name them after the table name. For example, if we say:

A violation of the constraint will return a message like:

2014-11-12

I was teaching a SQL 2014 class yesterday and the students were using the current SQL Server 2014 Enterprise (on Windows Server 2012 R2) template.

We were using the Table Memory Optimization Advisor (right-click a table in Object Explorer within SQL Server Management Studio). I had several people in the class that reported that when they got to the primary key migration screen, that they couldn’t interact with the screen because the checkboxes were not present in the displayed list of columns.

2014-11-06

Nice to see some updated connectors for Oracle and Teradata for SQL Server Integration Services developers/users.

Version 3.0 of the Attunity connectors have been released. Some of these have substantial improvements. For example, the list of enhanced features for the Teradata connector includes:

• Expose additional TPT Stream Attributes(TD_PACK and TD_PACKMAXIMUM) to provide maximum tuning flexibility.
• Support for loading table with columns using reserved words.
• Fix mapping for TIME(0) to DT_STR SSIS datatype.
• Can display table name more than 30 characters correctly.
• Support for block mode and set as default mode.
• Expose TD_SPOOLMODE for TPT Export for faster extracts.
• Support for Extended Object Names(EON), which allow UNICODE object names in the Data Dictionary tables.
• Adding new datatypes (TD_PERIOD_DATE, TD_PERIOD_TIME and TD_NUMBER)

2014-11-05

I got an email the other day from Sean and Jen at Midnight DBA ( www.midnightdba.com ) about their new tool Minion for managing index rebuilds and fragmentation:

With these tools, they have been a little more ambitious in some ways than the tools provided by Ola Hallengren ( https://ola.hallengren.com/ ) that have been our favourite tools for this work. I quite liked many of the concepts they have put into the tool. It still feels a bit version-1.0-ish to me but shows lots of promise. I liked the way that it’s all set up with a single script. I would, however, like to see more error handling, etc. in that script. For example, you should be able to run it twice without errors. With the script I looked at, that’s not possible.

2014-11-04

There was a question this morning on the SQL Down Under mailing list about how to determine the Windows groups for a given login.

That’s actually easy for a sysadmin login, as they have IMPERSONATE permission for other logins/users.

Here is an example procedure:

When I execute it on my system this way:

It returns the following:

Note that the Usage column could also return “DENY ONLY” or “AUTHENTICATOR”.

2014-10-31

Over the last year, I’ve delivered a number of partner enablement events for Microsoft. These events are low cost training sessions that run for three days. Days 1 and 2 cover SQL Server 2014 content, mostly regarding in-memory OLTP, clustered columnstore indexes, and Azure integration with hybrid systems. Day 3 covers the full Power BI stack.

We’re pleased to be running another set of these around the country:

Melbourne: November 5th to 7th

2014-10-30