Exploring SQL Server 2016 Query Store GUI

Introduction

Query store is a new feature, introduced in SQL Server 2016, that allows database administrators to historically review queries and their associated plans using the GUI available in SQL Server Management Studio, as well as to analyze query performance using certain Dynamic Management Views. Query Store is a database scoped configuration option and is available for use if the compatibility level of the database in question is 130.

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Performing Data Changes Audit Using Temporal Table

SQL Server 2016 has introduced a feature called ‘System versioned temporal table’. Using normal table, you can retrieve current data; while using a system-versioned temporal table, you can retrieve data which was deleted or updated in the past. To do that, a temporal table will create a history table. The history table will store old data with “start_time” and “end_time”. Which indicates a time period for which the record was active. Read More

SQL Server Table Partitioning

Problem

In this article, we will focus on the demonstration of table partitioning. The simplest explanation of table partitioning can be called as dividing large tables into small ones. This topic provides scalability and manageability.

Why do we need table partitioning?

Assume that we have a table and it grows day by day. In this case, the table can cause some problems which need to be solved by the steps defined below:

  • Maintain this table. It will take a long time and consume more resources (CPU, IO etc.).
  • Back up.
  • Lock problems.

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Real-Time Operational Analytics and Non-Clustered Column Store Index

In this article, we will focus on real time operational analytics and how to apply this approach to an OLTP database. When we look at the traditional analytical model, we can see OLTP and analytic environments are separate structures. First of all, the traditional analytic model environments need to create ETL (Extract, Transform and Load) tasks. Because we need to transfer transactional data to the data warehouse. These types of architecture have some disadvantages. They are cost, complexity and data latency. In order to eliminate these disadvantages, we need a different approach.  Read More

SQL Server Triggers: Understanding and Alternatives

The SQL Server trigger is a special type of stored procedures that is automatically executed when an event occurs in a specific database server. SQL Server provides us with two main types of triggers: the DML Triggers and the DDL triggers. The DDL triggers will be fired in response to different Data Definition Language (DDL) events, such as executing CREATE, ALTER, DROP, GRANT, DENY, and REVOKE T-SQL statements. The DDL trigger can respond to the DDL actions by preventing these changes from affecting the database, perform another action in response to these DDL actions or recording these changes that are executed against the database. Read More

Example of Improving Query Performance with Indexes

In this article, we’ll look at how an index can improve the query performance.

Introduction 

Indexes in Oracle and other databases are objects that store references to data in other tables. They are used to improve the query performance, most often the SELECT statement.

They aren’t a “silver bullet” – they don’t always solve performance problems with SELECT statements. However, they can certainly help.

Let’s consider this on a particular example.

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Implementing a Common MS SQL Server Performance Indicator

Introduction

There is often a need to create a performance indicator that would show database activity related to the previous period or specific day. In the article titled “Implementing SQL Server Performance Indicator for Queries, Stored Procedures, and Triggers”, we provided an example of implementing this indicator.

In this article, we are going to describe another simple way to track how and how long the query execution takes, as well as how to retrieve execution plans for each time point. 

This method is especially useful in the cases when you need to generate daily reports, so you can not only automate the method but also add it to the report with minimum technical details.

In this article, we will explore an example of implementing this common performance indicator where Total Elapsed Time will serve as a metric.

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Missing Indexes in MS SQL or Optimization in no Time

When executing a query, the SQL Server optimizer tries to find the best query plan based on existing indexes and available latest statistics for a reasonable time, of course, if this plan is not already stored in the server cache. If no, the query is executed according to this plan, and the plan is stored in the server cache. If the plan has already been built for this query, the query is executed according to the existing plan.

We are interested in the following issue:

During compilation of a query plan, when sorting possible indexes, if the server does not find the best index, the missing index is marked in the query plan, and the server keeps statistics on such indexes: how many times the server would use this index and how much this query would cost.

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