Disasters are always bad. Recovering from disaster is a skill and needs a lot of planning and practice. One of my clients had a disaster and built a new machine to restore the backups. They tried a few attempts to install SQL Server but were having issues. Finally, they contacted me for consultation to fix rule reporting services catalog database file existence.
How Many Foreign Key Can You Have on A Single Table? – Interview Question of the Week #096
Question: How Many Foreign Key Can You Have on A Single Table?
I was asked above question in my recent SQLPASS presentations. I quickly answered that it is 253. However, after I returned home when I searched a bit more, I realized that my answer is not complete, hence this blog post.
MySQL – Fix Error – WordPress Database Error Duplicate Entry for key PRIMARY for Query INSERT INTO wp_options
As many of you know that this blog runs on Wordpress and under the hood of Wordpress there is a MySQL database. MySQL database is quite good and is able to hold massive traffic this blog receives every day. However, just like any database MySQL needs tuning as well as proper management of the same. In this blog post we will discuss about how I received a very weird error Wordpress Database Error and how I resolved it.
Does Dropping Primary Key Drop Non-Clustered Index on the Column? – Interview Question of the Week #085
Question: When we drop primary key on the column, does it automatically drop a non-clustered index on the same column (if created)?
Before we see answer of this question, I suggest you read following three blog posts, they discuss various similar aspects related to the primary key and clustered index.
Database Sharding – How to Identify a Shard Key?
I have written a number of posts in the past working on shared databases and the concepts around these can be read at Sharding or No Sharding of Database – Working on my Weekend Project for the starters point of view. In a recent discussion at a user group, I had someone ask me what is the rationale around building a sharding key and what should be used for sharding their database. The concept, though common, it is not in black-and-white to what should be used as an sharding key. There are guiding principles which can be applied. Let us learn about Database Sharding.
How to Drop Clustered Index on Primary Key Column? – Interview Question of the Week #084
Question: How to drop clustered index, which is created on primary key?
Answer: If you thought the answer as simple as following script, you are wrong.
DROP INDEX PK_Table1_Col1
ON Table1
GO
SQL SERVER – Installation Fails With Error – A Constraint Violation Occurred
In my recent past, I have helped around 10 customers who have had similar problems while installing SQL Server Cluster on windows. So I thought it would be a nice idea to pen it down as a blog post so that it can help others in future. In this blog post we will discuss about Installation Fails With Error – A Constraint Violation Occurred.