Null marks are a fact of life in relational databases. Sometimes it is good to revisit the basics of how they are treated in basic system functions and T-SQL because they can be tricky. Look at the following scenarios of how null marks are treated different than the unsuspecting eye might see.
SQL Saturday – Raleigh 2017 – Amazing Professional Community
This Saturday was SQL Saturday for Raleigh. Attendance was strong, classrooms were filled, and the event was a success. When I attend these events it amazes me how strong the SQL community is. Speakers travel from states away, volunteers setup and plan the event, vendors sponsor the event and meet at their booths with participants, and people come to learn on an Saturday.
That really says something about SELECT individuals who INNER JOIN with each other ON a Saturday WHERE the goal is to learn from each other as a GROUP BY sharing knowledge we are lucky enough HAVING such a great community. I’ll stop now in ORDER to show some pictures of day!
SHA-1: When 2 Message Digests Collide
A SHA-1 vulnerability discussed 10 years ago has now been exploited. On February 23, researchers at Google and the CWI Institute in Amsterdam announced they have demonstrated its 1st known hash collision.
Introvert at Work – How to Survive and Be Successful as a Software Engineer
Calling all introverts! This post is for you if:
- People drain your energy and you gain it back from being alone
- You sit at your desk with huge air traffic controller headphones on most of the day
- You took a personality test and it said you are an introvert
If you work with software, chances are you are an introvert. There are literally dozens of us! Yet we often wear our introversion as a Scarlet Letter instead of the champion belt that it is. Keep reading to find out how to use your introversion to your advantage at work.
DRM Security Concerns | Who does the IoT Obey?
I saw this video of a keynote speech given at the O`Reilly Security Conference in October 2016. Cory Doctorow gives a compelling talk about the thorny issues surrounding DRM and security research, privacy violations, and private property abuses.
Watch the video (32 min):
Hour of Code 2016 | Expose, Inspire, Teach
I have volunteered in the Hour of CodeTM for the second time this year. This year and last I went to 2 schools and worked with elementary school children on the basics of code.
Using T-SQL to Insert, Update, Delete Millions of Rows
Challenges of Large Scale DML using T-SQL
Using T-SQL to insert, update, or delete large amounts of data from a table will results in some unexpected difficulties if you’ve never taken it to task.
Let’s say you have a table in which you want to delete millions of records. If the goal was to remove all then we could simply use TRUNCATE. However, if we want to remove records which meet some certain criteria then executing something like this will cause more trouble that it is worth.
Why not run the following in a production environment?
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1 2 3 |
DELETE FROM myTable WHERE columnA = 'whatever'; |
- Transaction log growth – expect a large transaction like this to cause the transaction log to expand. Calls to expand the database files are some of the most expensive operations SQL Server makes to the OS. Hopefully the initial sizing was good and the growth settings are reasonable.
- Blocking – concurrency is going to increase the likelihood of lock escalation. That will lead to the possibility of excessive blocking.
- Rollbacks – if the SPID is killed then the transaction will enter a rollback state. For very large transactions this can take a lot of time. Don’t even think about killing or stopping SQL Services during a rollback unless you want a corrupt database!
What can we do to improve this?
We follow an important maxim of computer science – break large problems down into smaller problems and solve them.
We break up the transaction into smaller batches to get the job done. Each of the above points can be relived in this manner. Let’s take a look at some examples.
SQL Server 2005 – The End of an Era
This year marks the end of life for Microsoft SQL Server 2005. Remember Query Analyzer? Enterprise Manager? In the dark times before BIDS and the Visual Studio shell we called Management Studio emerged, we had to manage and develop the database using a crude form of an MMC snap-in and a text editor whose power rivaled that of WordPad.
SQL Saturday – Charlotte
I made the journey to Charlotte for SQL Saturday this year. It was a solid event with good attendance, interesting speakers and topics, and in a nice facility.
Snowden Movie – Powerful with Lingering Questions
On Wednesday I attended an early screening of Oliver Stone’s Snowden. After the movie was a live interview with director Oliver Stone, Joseph Gordon-Levitt, Shailene Woodley, and Edward Snowden. Aside from it being a great movie I want to discuss the themes and thoughts it leaves the viewer.
From a technology standpoint there are some very important points in the movie to consider.