Nowadays security breaches happen way to frequently. As DBA’s we should all take extra care with sensitive data and ensure we are encrypting correctly. But some of us forget to take it a step farther and don’t encrypt our backups. For those working in an ultra data sensitive environment I highly recommend you go this extra step. As of SQL 2014, SQL Server now has the ability to encrypt your data during the backup process. Not only that but they have made the process simple. Prior to 2014, the only way to encrypt backups was Transparent Data Encryption (TDE), and that requires Enterprise Edition which made this out of reach for most. First…
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Microsoft has long given us DBA tools and suggestions to help tune databases, to fix queries with indexes, and many times they were of questionable merit. We have all seen the dreaded dta_index names in a database and rolled our eyes knowing that sometimes these indexes are not what is needed. While the Database Tuning Advisor, has gotten better over time it is still not a tool more senior DBAs use. Microsoft made big steps in helping DBAs with performance with the introduction of Query Store in both Azure SQL Database and SQL Server 2016. Query Store collects execution and run-time performance information. Microsoft has taken an additional leap with…
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Microsoft gives you two purchasing models for your Azure SQL Databases (SQL DB), a DTU and a vCore based model (logical CPU’s). Both options allow you to scale up or down based on your compute and storage requirements. Regardless of which model you choose performance tuning can save you money using SQL DB. DTU (s) (Database Transaction Units) measure “a blended measure of CPU, memory, and data I/O and transaction log I/O” that Microsoft uses to help estimate which DTU based Service Tier you should be using. By reducing your I/O, memory or CPU consumption you utilize less DTUs or cores and thus can step down service tiers. Stepping down service…
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Starting in SQL Server 2012 and in Azure SQL Database, Microsoft introduced the concept of a contained database. A contained database is a database that is completely un-reliant on the instance of SQL Server that hosts the database including the master database–theoretically this makes a database much easier to move between servers (you’ll note the absence of SQL Agent jobs from this post, that’s a difference problem.). One of the biggest benefit is that it allows database level authentication, so there no need to have user logins on server level. Contained database now enables us to make a database more portable. I can backup and restore to any instance of…
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July 1st is a day all Microsoft Most Valuable Professionals (MVP) wait patiently at their computers hitting F5 over and over again waiting to find out if they have been renewed for the upcoming year. I am proud to announce that Denny Cherry and Associates once again have FOUR MVP’s on staff. Denny, Monica and Joey have all been renewed for 2018. John, being newer to the program, will not be up for renewal until the 2019 award cycle. Combine we have over 17 years of MVP program experience. Big mile stones were hit by both Denny and Joey. Denny was awarded his 10th and Joey reached his 5th.…
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Ever seen the below error? Until this week I hadn’t. So, I figured I’d take a little time and introduce it to those that had not. Error Description: Length of LOB data (65754) to be replicated exceeds configured maximum 65536. Use the stored procedure sp_configure to increase the configured maximum value for max text repl size option, which defaults to 65536. A configured value of -1 indicates no limit We ran into an issue with a customer this week, this error was flooding the error log. After a little digging I found it had to do with transactional replication (also applies to Change Data Capture) they had setup which included…
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I typically don’t write opinion posts, but given recent events I thought it was important to follow up on one of my tweets. Last week, I tweeted about Stack Exchange and my thoughts on the lack of respect in the responses to those who take the time ask questions in forums. I had many people ask as to what I was referring to specifically, including some Microsoft employees. My response was (and still is) that I don’t believe in mob reactions or smearing anyone’s name and chose not to reveal the details. My reason for posting that tweet was just to remind those in the community that we have all been beginners once and none…
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A few weeks ago, I wrote Part 1, 2 and 3 of this series, which was a beginner’s guide to Always Encrypted. In part 4, I am going to talk about the changes that are coming in vNext of SQL Server. As I discussed in part 3 there are many roads blocks the can stop the implementation of Always Encrypted (AE). In the current available versions of SQL Server 2016 and 2017, along with Azure SQL Database, the cost of using AE was way too high for many companies. There are so many code changes needed to implement AE that moving to it is not cost effective for them. Microsoft recognizes this and has…
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Following up on my last post about the Cardinality Estimator let’s talk about column statistics and how they work and play a part in execution plans. The cardinality estimator relies heavily on statistics to get the answer to selectivity (the ratio of distinct values to the total number of values) questions and calculate a cost estimate. This hopefully gives us the best possible execution plans for queries. In this post, I will show you where to find information about what your statistics contain and information regarding each of those fields. Then we will look at the impact of over and under estimations caused by stale or missing statistics (or even data…
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Sometimes people speak “SQL” and expect you know all the terminology. In recent a conversation about query plans I was ranting on and on about how the predicates were written when the person stopped me and asked a very simple question. Like a light bulb going off, it reminded me that not everyone knows what the other person is talking about when terminology is mentioned without clarification. So, this post will answer that persons very valid simple question. What is a SQL Predicate? Predicates are expressions that evaluate to TRUE, FALSE, UNKNOWN. There are two types of predicates Filtered Predicates and Join Predicates. Filtered Predicates cover your WHERE or HAVING…
