What is ransomware Ransomware is a type of malicious software that locks access to user files until a ransom is paid. Quite common “locking mechanism” is by encrypting all files on a user computer, server or even the entire network. Encryption is a process of scrambling original data using an encryption key. The same key … Read more
Let’s take a look at different ways of reading the SQL Server ERRORLOG….I often come across large ERRORLOGS mainly because they are not being recycled frequent enough, or not at all. Sometimes, despite the frequent recycling, the ERRORLOG can grow to unmanageable size. This has recently happened to me during a large transaction rollback over Synchronous Availability Group. Within a few hours, the ERRORLOG log grew to 5GB in size due to “Sending page request for Undo” messages.
A lot of database administrators and developers like to use the SQL Server Management Studio to make changes to the database schema directly. As a production DBA, I can definitely say that there are situations where this is acceptable and even desired, however, in most cases a Visual Studio Database Project is a much better approach. I have made a switch from developing in SSMS to Visual Studio several years ago and never looked back.
An important element of performance monitoring is knowing what SQL agent jobs run at what time to understand and avoid potential clashing. Notice the underlined what time – time correlation is very important when it comes to performance but finding it is not always easy. I wrote a simple PowerShell script to help visualise what jobs run and when
Concept You may have come across a term multi-tiered storage. This means, that the storage solution has multiple arrays, fast and expensive and slow but cheap. Files accessed very frequently are stored on very fast SSD disks, files accessed less frequently are stored on the much cheaper but much slower spinning disks. Files designated for … Read more
Abstract PowerBI Desktop is a data analytics and presentation tool. Defining data sets is very easy and usually involves creating connection string to the source data and defining objects to pull data from. Alternatively, for SQL databases we can write custom SQL script to query source data. However, if we want to pull data from … Read more
As data professionals, we often need test data, whether for functional testing, to satisfy business logic criteria or for non-functional, to satisfy performance requirements. We must also not store any sensitive or personal information in non-production systems and doing so could be against Data Protection Regulations (GDPR). A common approach is to refresh test environments … Read more
I often help improve the performance of a SQL Server or an application. Performance metrics in SQL Server are exposed via Dynamic Management Views (DMVs). However, DMVs only provide a view of the current state and no history. This is important as it makes it particularly difficult to draw a bigger picture of how the system is behaving over time and what problems are occurring during overnight batch processing or during peak operational times, for example when users log in to the system at 8 am or when they leave for lunch at 1 pm. To address this deficiency I have built a simple yet comprehensive SQL Server Performance Dashboard in PowerBI.
I recently got an ultra wide screen and realised that the Windows taskbar is a bit of waste. Let me explain. On an ultra wide screen, the task bar will be very likely just empty most of the time, taking up the precious Y axis of the screen: Since there are many more pixels on … Read more
The identity value in relational databases is a field that increases automatically. It is often used to create surrogate primary keys. Surrogate keys Surrogate keys are meaningless and are only used to uniquely identify the row, not the data itself. For example, assume the following table: As we can see, the identity values are 1, … Read more