Do you think about something when you create a new database? I guess that most of you would say no, since we all use default parameters, though they are far from being optimal. However, there is a bunch of disc settings, and they really help to increase system reliability and performance. (more…)
A recent announcement on the release of several SQL Server tools has raised expectations across various groups. Product requirements and business are almost always a trade-off, and striking the right balance in a product in terms of the toolset is a sign of a successful product. After testing the SQL Operations Studio, I feel that it’s a promising tool for many developers, administrators, and DevOps specialists. In my opinion, the mssql-cli tool adds another feature to SQL Server in order to make it a leading database product.
What is TempDB?
TempDB is a system database in Microsoft SQL Server used as a store of internal objects, row versions, work tables, temporary tables, and indexes. TempDB is available for use to all participants connected to a SQL Server instance (it is a global resource). For those familiar with other database flavors, the tempDB database is similar to the TEMP tablespace in Oracle. To put it mildly, anything that cannot fit your instance memory spills over to the tempdb data files.
As DBAs, we generally come across our clients complaining that the current Production Server is not able to hold the load on the server and whether the load may be balanced with the Secondary Server. This is possible with a database in DR Server with Read-only database in Log Shipping and Secondary SQL Server replicas in Always On Availability Group. The biggest advantage of Always On Groups is that it allows us to set up group level HA for any number of databases and we can create up to four secondary replicas and this is a combination of Clustering, Log Shipping and Database Mirroring where the data transmission is more flexible and functional.
All the database developers more or less write database unit tests that not only help in detecting bugs early but also save a lot of time and efforts when the unexpected behavior of database objects becomes a production issue.
Nowadays, there are a number of database unit testing frameworks such as tSQLt along with third-party unit testing tools including dbForge Unit Test.
On the one hand, the benefit of using third-party testing tools is that the development team can instantly create and run unit tests with added features. Also, using a testing framework directly gives you more control over the unit tests. Therefore, you can add more functionality to the unit testing framework itself. However, in this case, your team must have time and a certain level of expertise to do this.
This article explores some standard practices that can help us to improve the way we write database unit tests.
Before going through the Forwarded Records performance issue and resolving it, we need to review the structure of the SQL Server tables.
Table Structure Overview
In SQL Server, the fundamental unit of the data storage is the 8-KB Pages. Each page starts with a 96-byte header that stores the system information about that page. Then, the table rows will be stored on the data pages serially after the header. At the end of the page, the row offset table, that contains one entry for each row, will be stored opposite to the sequence of the rows in the page. This row offset entry shows how far the first byte of that row is located from the start of the page.
The PIVOT statement is used to convert table rows into columns, while the UNPIVOT operator converts columns back to rows. Reversing a PIVOT statement refers to the process of applying the UNPIVOT operator to the already PIVOTED dataset in order to retrieve the original dataset.
In this article, we will study these three concepts on different examples.
Often, we need to ensure fault tolerance of MS SQL Server DBMS, especially, when there is no Enterprise edition, but only the Standard one.
We would like to note that we are not going to examine the Express edition because there are significant restrictions to this instance. Sure, we can bypass some of them. For example, to resolve the issue with the database size of 10 GB, we can split a large database into smaller ones. To do this, we can create a new database based on a certain property, and combine the selections from the same tables of different databases in the views in the principal database. However, fault tolerance in the Express edition will be performed either by a system administrator or by using your own or third-party software.
In this article, we are going to explore all existing standard fault-tolerance technologies for MS SQL Server 2017 and an example of implementing the most suitable unified standard of fault-tolerance in the Standard edition.
In this article, we will examine Database Scoped Configurations and SQL Server 2017 Automatic Plan Correction. Microsoft added new features to SQL Server 2017 that improved the query performance. (more…)