A client recently discovered a discrepancy on one of our reports that showed an improvement in performance metrics but was inaccurate. Our reports came from a software tool, which showed the average performance throughout the day. It derived this number from periodic checks and the frequency changed, which affected our report. When we showed an […]
In SQL Server, when talking about table partitions, basically, SQL Server doesn’t directly support hash partitions. It has an own logically built function using persisted computed columns for distributing data across horizontal partitions called a Hash partition.
Q1: What is the difference between a Heap table and a Clustered table? How can we identify if the table is a heap table? A Heap table is a table in which, the data rows are not stored in any particular order within each data page. In addition, there is no particular order to control the data […]
So far, we discussed many de-facto details about SQL Server database backup and restore. In this 15th article of the series, we are going to discuss, the file-group and piecemeal database backup and restore process.
Description Fixing bad queries and resolving performance problems can involve hours (or days) of research and testing. Sometimes we can quickly cut that time by identifying common design patterns that are indicative of poorly performing TSQL.
Key Performance Indicator (KPI) A Key Performance Indicator aka KPI is a metric which objectively measures the numeric equivalent of goals or targets of a company, team or an organization. Any individual or a community which has a numerical target can measure success of their goal with key performance indicators. In all business roles and […]
Error handling overview Error handling in SQL Server gives us control over the Transact-SQL code. For example, when things go wrong, we get a chance to do something about it and possibly make it right again. SQL Server error handling can be as simple as just logging that something happened, or it could be us […]
The WRITELOG wait type is one of those wait types that can often be seen quite frequently on SQL Server, and that can cause a lot of headaches for DBAs. The WRITELOG wait time represents the time that accumulates while waiting for the content of the transaction log cache to be flushed to the physical […]
SQL Server supports table valued functions, what are functions that return data in the form of tables. JOIN operations in SQL Server are used to join two or more tables. However, JOIN operations cannot be used to join a table with the output of a table valued function. APPLY operators are used for this purpose.
When maintaining SQL Server, it is essential to get an accurate perception of how busy it is. Two metrics that are often considered as indicators of how busy SQL Server is are Batch Requests/sec and Transaction/sec. When those metrics trend higher, they often affect all other metrics and make them go higher as well. While […]
SQL Data Sync is a service that allows synchronizing data across multiple Azure SQL databases and on-premises SQL Server databases. In this article, a base concept of how the SQL Data Sync service works will be explained as well as what the requirements and limitations are when want to create data synchronization by using SQL […]
A tail-log backup is a special type of transaction log backup. In this type of backup, the log records that have not been backed up are captured. This prevents data loss and maintains the log chain sequence.
In the previous articles of this series (see the full article TOC at bottom), we discussed the internal structure of SQL Server tables and indexes, the guidelines that you can follow in order to design a proper index, the list of operations that can be performed on the SQL Server indexes, how to design effective […]
In the previous articles of this series (see the full article TOC at bottom), we discussed the internal structure of both the SQL Server tables and indexes, the best practices that you can follow in order to design a proper index, list of operations that you can perform on the SQL Server indexes, how to […]
Our organization must restrict permissions and prove to an independent party that we investigate access and restrict permissions. We restrict permissions to objects using least permissions and give full access to an exceptional few based on an organizational design that follows best practices. What can we do additionally that will help us prevent unauthorized access […]
In the previous articles of this series (see the full article TOC at bottom), we discussed the internal structure of the SQL Server tables and indexes, the best practices to follow when designing a proper index, the group of operations that you can perform on the SQL Server indexes, how to design effective Clustered and […]
In this article in our stairway series on SQL Server backup and restore, we shall discuss the importance of understanding the internals of the page restoration for a database administrator. Most of the time, performing a page-level restore suffices for database availability. A good backup strategy is a key to recovery or restoration, and SQL […]
This article explains data security for accessing sensitive data and restricts access in application using SQL Views and stored procedures. We recently faced a leak of information for one of our employees that involved data which caused a conflict within our company, even if it was not personally identifiable information (PII data). When we investigated […]
Introduction Foreign key constraints are a powerful mechanism for preserving referential integrity in a database. They can also represent a challenge when doing bulk table loads, since you need to find a “base” table to start with – that is, a table that has no foreign key constraints defined. Let’s label tables like this as […]
Data conversion is one of the most fundamental tasks of any programming language. Data received from different sources is often not in the right format. For example, if you receive an XML file where age is in the string format and you want to calculate an average age for the people in the file you […]
One of the paramount ways to guard data within a database is to utilize database encryption. However, no one encryption solution is perfect for all databases. Which encryption solution you select totally depends on the requirements of your application. Note that more powerful encryption for larger amounts of data requires a healthy amount of CPU. So, […]
We receive many database alerts with many of the alerts logging some of these same alerts or information to files or tables. What we’ve found over time is that the logging is now costing us quite a bit of resource. Our logging server (where both files and table logging are stored) has had a few […]
So far, we’ve discussed several phases of backup that starts with planning, creating, strategizing and implementing. In this article, we are going to see how database administrators can define the strategy to improve backup performance and efficiently manage backups in SQL Server 2017. The following are the topics of discussion: Discuss checkpoints Discuss the enhancements […]
In the previous articles of this series (see the full article TOC at bottom), we discussed the internal structure of both SQL Server tables and indexes, the main guidelines that you can follow to design a proper index, the list of operations that can be performed on the SQL Server indexes, and finally how to […]
In the previous articles of this series (see below for the full index of articles), we went through the internal structure of SQL Server tables and indexes, listed a number of guidelines that help in designing a proper index, discussed the operations that can be performed on SQL Server indexes and finally showed how to […]
© Quest Software Inc. ALL RIGHTS RESERVED. | GDPR | Terms of Use | Privacy