Esat Erkec

Esat Erkec
Latest posts by Esat Erkec (see all)
How to read a file of JSON in SQL Server with OPENJSON function

How to parse JSON in SQL Server

September 15, 2020 by

In this article, we will learn how to parse and query JSON in SQL Server with the help of the OPENJSON function. Firstly, we will briefly look at the data structure of the JSON and then we will learn details of the parsing and querying JSON data using the OPENJSON function.

Read more »
Measuring disk latency with Perfmon for SQL Server troubleshooting

SQL Server troubleshooting: Disk I/O problems

August 17, 2020 by

In this article, we will discuss how to resolve I/O problems that is a very important point for the SQL Server troubleshooting. The storage subsystem is one of the significant performance factors for the databases. Detecting and identifying I/O problems in SQL Server can be a tough task for the database administrators (DBAs). Generally, the underlying reasons for the I/O problems can be:

Read more »
Read I/O and Write I/O sections of the performance test

Using Diskspd to test SQL Server Storage Subsystems

July 28, 2020 by

In this article, we will learn how to test our storage subsystems performance using Diskspd. The storage subsystem is one of the key performance factors for SQL Server because SQL Server storage engine stores database objects, tables, and indexes on the physical files. Therefore, the storage engine always interacts with the disk subsystem because of data processing. In this context, when a bottleneck occurs on the storage subsystems, it causes a negative impact on SQL Server performance. It would be the right approach to measure the performance of the disks to be used before the SQL Server installation based on their usage purposes. For example, OLTP databases have to complete delete, insert, and update processes in a short time but OLAP databases handle a huge amount of batch data. In this case, the storage requirement of these two database systems should differ from each other. In short, it is a best practice to test and analyze the performance of the storage subsystems according to their usage purposes so that we can eliminate the I/O problems in advance.

Read more »
Performance comparison Batch mode vs Row mode

SQL Server 2019 new features: Batch Mode on Rowstore

May 27, 2020 by

In this article, we will explain batch mode on rowstore feature, which was announced with SQL Server 2019. The main benefit of this feature is that it improves the performance of analytical queries, and it also reduces the CPU utilization of these types of queries. Behind the scene, this performance enhancement uses the batch mode query processing feature for the data, which is stored in row format. Also, this feature has been using by columnstored indexes for a long time.

Read more »
SQL Server Query Tuning: Use the UNION ALL operator instead of to UNION operator

Getting started with SQL Server Query Tuning

April 21, 2020 by

This article will cover some essential techniques for SQL query tuning. Query tuning is a very wide topic to talk about, but some essential techniques never change in order to tune queries in SQL Server. Particularly, it is a difficult issue for those who are a newbie to SQL query tuning or who are thinking about starting it. So, this article will be a good starting point for them. Also, other readers can refresh their knowledge with this article. In the next parts of this article, we will mention these techniques that help to tune queries.

Read more »
What is pagination in SQL Server?

Pagination in SQL Server

April 14, 2020 by

Pagination is a process that is used to divide a large data into smaller discrete pages, and this process is also known as paging. Pagination is commonly used by web applications and can be seen on Google. When we search for something on Google, it shows the results on the separated page; this is the main idea of the pagination.

Read more »
Listing temporary tables in tempdb database

How to drop temp tables in SQL Server

March 23, 2020 by

Temporary tables, also known as temp tables, are widely used by the database administrators and developers. However, it may be necessary to drop the temp table before creating it. It is a common practice to check whether the temporary table exists or not exists. So, we can eliminate the “There is already an object named ‘#temptablename’ in the database” error during the temporary table creation.

Read more »