Features

Ranga Babu
adding database to an existing failover group

Azure SQL Server auto-failover groups

July 18, 2019 by

In this article, we will review how to set up auto-failover groups in Azure SQL Server and how failover group is different from active geo-replication in Azure. Auto-failover group is an Azure SQL database feature that replicates one or a group of databases to the secondary Azure SQL server in the cross-region. We cannot have a secondary server in the same region. This feature is used to failover all the databases in the failover group in case of disaster and the failover is automatic.

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Ranga Babu
Geo-Replication

Azure SQL database Geo-Replication

July 15, 2019 by

In this article, we will review how to set up Geo-Replication on Azure SQL databases. Geo-Replication is an Azure SQL database feature that allows you to create a readable secondary database in the same region or cross-region. We can failover to the secondary database in case of an outage for a long time on the primary database server. We can also use this feature to migrate a database from one server to another server in the same or cross region with minimal downtime. Geo-replication uses the Always-on feature to replicate committed transactions to the secondary database asynchronously.

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Rajendra Gupta
Availability group validations

Applying Transaction Logs to the Secondary Replica in SQL Server Always On Availability Groups

July 12, 2019 by

Introduction

SQL Server Always On Availability Groups provides HADR solutions for the SQL databases. Here HA refers to high availability and DR refers to disaster recovery. The priority of this feature is to keep the database highly available and then provide Disaster recovery. Due to this reason, if the secondary replica goes down in a synchronous data commit mode, SQL Server changes commit mode to Asynchronous so that users can continue run the transactions and a secondary replica can be in sync later once it bought up. SQL Listener also points to the primary replica and continues redirects connection to the primary replica.

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Rajendra Gupta
Execution plan and statistics

SQL Server Statistics in Always On Availability Groups

May 27, 2019 by

Introduction to SQL Server Statistics

SQL Server Statistics are an essential part of query performance in SQL Server. They help the query optimizer to prepare a query plan using the distribution of values in participating rows. If we do not have updated statistics, it might lead to resource intensive query execution plan. For example, for a large table having a billion records, SQL may choose to have an index scan instead of an index seek.

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Rajendra Gupta
sql server always on

SQL Server Always On Availability Group Data Resynchronization

May 9, 2019 by

In my previous article Data Synchronization in SQL Server Always On Availability Group, we described a scenario where if a secondary replica goes down in synchronous data commit mode, SQL Server Always on Availability group changes to asynchronous data commit mode. It ensures that users can get their transaction commit irrespective of waiting for a secondary replica to come online.

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Priyanka Devre
View snapshot agent status

Add new articles, drop the article, change the snapshot folder path and Data filter rows in SQL Server Replication

April 2, 2019 by

In the last articles, we have learned Configuring Snapshot and Transactional SQL Server replication and Configuring Peer to Peer and Merge SQL replication. Now, once we configured SQL Server replication, there will be some instances where we need to modify the SQL Server replication configuration as per the project updates. In this article, we will learn a few modifications in the existing SQL Replication such as Add new article, drop an article and change the Snapshot folder path and data filter in the current SQL Server replication.

Ahmad Yaseen
sys.databases result showing log_reuse information

SQL Server Transaction Log Growth Monitoring and Management

April 1, 2019 by

In the previous articles of this series on the SQL Server Transaction Log, we discussed the importance of the SQL Server Transaction Log and the role that it plays in maintaining the database consistency, by ensuring that the committing transactions data will be preserved and the failed transaction will be rolled back. It also helps to recover the database to a specific point in time in case of system or hardware failure. This is achieved by writing a log record to the SQL transaction log file before writing the data pages to the physical data file, using Write-ahead Logging process.

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Rajendra Gupta
comparison on transaction log growth between Accelerated Database Recovery feature On and Off.

Accelerated Database Recovery and Long Running Transactions with Transaction Log Growth

March 21, 2019 by

In my previous article in this series Accelerated Database Recovery; Instant Rollback and Database Recovery, we talked about a potential DBA painkiller to resolve long waiting times for database recovery and rollback scenarios using Accelerated Database Recovery. In this article, we will look at one more painful challenge for DBAs, Long Running Transaction with Transaction log growth.

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Ahmad Yaseen
SQL Server Always on Failover Cluster topography

SQL Server Transaction Log and High Availability Solutions

March 21, 2019 by

In the previous article of this series on the SQL Server transaction log, we discuss the SQL Server database recovery models, Full, Simple and Bulk-Logged, and the how the recovery model option of the database affects the way the SQL Server Engine works with the transaction logs. In this article, we will discuss the different types of high availability and disaster recovery solutions and the role of the SQL Server transaction log in these technologies.