In my earlier posts, we have seen how database snapshots work, and how the Buffer Pool is used when we query Snapshot Databases. In this post, we will see how Database Snapshots work, when they are created against Mirrored Databases. Let us assume we have a mirroring setup, as described in the below...

In my earlier post, we have seen what Database Snapshots are, and how the Database Snapshots are maintained by the SQL Server Database Engine. In this post we will see how the data and index pages, belonging to the Snapshot, are managed in the Buffer Pool. Before we start drilling down further, let me...

In this post, we will explore the internals of Database Snapshot. Most of this information is already available in the Internet, in the posts authored by the SQL Server Development Team and the CSS Escalation Team; however, through this post we will attempt to consolidate all of these information for...

Few months back, I was working with one of my customers, who was engaged by his client to design a Survey Module. Nothing very fancy about the module, but the kind of reports that were to be delivered made it really tricky. Let me explain the requirements first: When customers click on a Survey Link...

If you have read my earlier post , you might be saying “Heck! This guy loves to post questions without providing proper answers!” Believe me, that is not my intention. My intention here is to help you understand common mistakes that people make, so that you can avoid them in your projects. The biggest...

If you have read my earlier blog post on the Importance of data-types , you might be wondering, “What the heck is going on here?” I had already written in that post the reason behind the slow performance – the EmpCountry column in the Employee table is CHAR(2) which cannot be directly compared with NCHAR...

Assume that I have a database in Bulk Logged Recovery Model, and I perform a bulk operation that is minimally logged. Now, if I take a Log Backup, should not my Log Backup File Size be smaller than if I had performed the same operation in Full Recovery Model? I have seen many people confused by this...

Why did we develop DBMS systems? Not just for storing data – but also to be able to search for and retrieve stored data, and we define what our search criteria should be. This was probably true a couple of decades back, but we have come a long way now. With the huge advancement of technology...

One of my friends was asking this to me offline the other day: "I have Database in SQL Server, which is both Mirrored as well as Log Shipped. Log backups happen every 15 minutes; Mirroring happens in Synchronous mode and does not involve a witness. I want to break Mirroring (Remove Mirroring) and...

I have been working with SQL Server Replication for over 4 years now; and till now each case that I work on gives me something new to learn. At the same time, every case amazes me by the intricate design that has gone into implementation of SQL Server Replication. With the wonderful GUI design, replication...

Very recently, I had the opportunity to help troubleshoot a Blocking issue that one of our customer's was experiencing. In my experience, this is a very common scenario that I have seen. However, while troubleshooting this issue, and more so, while we wrote code to reproduce the issue at our end, we...

Hi Friends, After a long break of about 8 months, I am back again!! Many things changed recently, and I was quite busy adopting to the changes – the most challenging was, of course, adopting myself to new parenthood. However, I am back again, with some new topics – topics that I have learnt or experienced...

In my earlier blog post on Shrinking the Transaction Log files in SQL Server , I had mentioned that a VLF can be truncated only when all transactions, that have at least one command written into the specified VLF have either been committed or rolled back. While this is true, I understand that it might...

Hi Friends, This post comes as a response to requests from many of our customers, who want to know the step by step process on how to configure SQL Server Database Mail to send emails using their Windows Live Mail Account or their Gmail Account. If you are using SQL Server 2005 or higher, you might have...

Hi Friends, I am back again after a long time. Last month was the end of yet another financial year, and all of us were very busy with the processes involved with each year-end. Now that all those are completed, I could find some time for my next blog post on database corruption. Here, I will be targeting...

Great news!!! Due to over-whelming customer demand for the " Lock pages in memory " support for the Standard Edition of SQL Server 2005 and 2008 , Microsoft has released Cumulative Updates that will help SQL Server 64 bit Standard Edition to "lock pages" . This feature was already...