Recovery

Prashanth Jayaram
Create Azure SQL Database using Azure portal to restore the geo backup

Quick start guide to Geo-restore in Azure SQL Database

November 24, 2020 by

Azure SQL Database—a cloud-based service model provides a platform to back up the data and ensure to keep the business up-and-running even after the disaster. The data is vital and backup of the data revolves around the process of backup, restoration, recovery, Business-Continuity-Plans (BCP), and disaster recovery (DR). In this article, we will learn:

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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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How to reconnect to a SQL Server instance when all credentials have been lost

March 3, 2017 by

The Problem

I came across a strange and rare situation at a client recently, where they asked me to resolve a problem on Microsoft SQL Server but did not give me any credentials to connect to the system. I asked them to state the actual problem and the reply was “we lost all credentials”. A number of questions started to generate in my mind. How are applications running? The Answer was “The application login is embedded in a DLL and it’s a third party application which we don’t have support”. How can you lose all the SQL Server credentials? The Answer “It was saved in a file and it was lost and the employee who knew it is no more working with the company”. Anyways, I had no choice but to have a solution for this strange problem.

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Prashanth Jayaram

SQL Server Database Recovery Process Internals – database STARTUP Command

February 14, 2017 by

A database recovery process is an essential requirement for database systems, It can be a tedious job and the process of recovery varies on lot of scenarios. The desire to improve recovery results has resulted in various procedures, but understood by few and prone to errors. In this article, I’ll illustrate the impact of stopping the database instance in the middle of a large transaction that was running and discuss several techniques and tools that are available for faster and successful recovery.

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Dinesh Asanka

Point in Time Recovery with SQL Server

December 19, 2016 by

Introduction

How often are you working with multiple environments? For example, if you are a database administrator who is responsible for a production environment as well as another environment, it most likely that you will be working with both environments simultaneously. What is the probability that you will execute a script on production, which actually needs to be executed on the other environment? I would say it is high. To prove this point let me present you an example.

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Ahmad Yaseen

Database checkpoints – Enhancements in SQL Server 2016

September 21, 2016 by

When a new row is inserted or an existing one is updated in your database, the SQL Server Database Engine will keep that change in the buffer pool in the memory first, without applying each change directly to the database files for IO performance reasons. These data pages located in the buffer pool and not reflected yet to the database files are called Dirty Pages. The SQL Server Database Engine uses a special kind of processes to write these dirty pages to the data and log database files periodically. These processes are called Checkpoints. The Checkpoint creates a mark that is used by the SQL Server Database Engine to redo any transaction that is committed, written to the database transaction log file without reflecting the data changes to the data files due to an unexpected shutdown or crash. Also, this recovery point that is created by the Checkpoint will be used to roll back any data changes associated with uncommitted transaction, by reversing the operation written in the transaction log file. In this way the SQL Server Engine will guarantee the database consistency. The time that is taken by the SQL Server Database Engine to redo and undo the transactions is called the Recovery Time. All information about the Checkpoints will be written to the database boot page to identify till which point the database files are synchronized with the buffer pool when the system wakes up after crash or shutdown.

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Derik Hammer

Measuring Availability Group synchronization lag

August 9, 2016 by

With all of the high-availability (HA) and disaster recovery (DR) features, the database administrator must understand how much data loss and downtime is possible under the worst case scenarios. Data loss affects your ability to meet recovery point objectives (RPO) and downtime affects your recovery time objectives (RTO). When using Availability Groups (AGs), your RTO and RPO rely upon the replication of transaction log records between at least two replicas to be extremely fast. The worse the performance, the more potential data loss will occur and the longer it can take for a failed over database to come back online.

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