Transaction log

Prashanth Jayaram

SQL Server transactional replication: How to reinitialize a subscription using a SQL Server database backup

September 13, 2018 by

A workload management is considered as a critical aspect of SQL Server transactional replication. Replication is the oldest of the high availability technologies in SQL Server and it is available since the inception of SQL Server. As a very mature technology, SQL Server transactional replication is also very robust and, in most cases, very straightforward to set up and manage.

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Prashanth Jayaram

SQL Replication: Basic setup and configuration

September 12, 2018 by

This is article is a continuation of the previous: SQL Server replication: Overview of components and topography.

By now, you’re familiar with the components of replication. So far, we’ve seen a lot of theory about replication. It’s a time for practical walkthrough of setting up a basic transactional SQL Replication system. The best way to get a feel for how SQL Replication is implemented and how it works is to see it in action.

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Prashanth Jayaram

How to setup a custom SQL Server transaction replication model with a Central Subscriber and Multiple Publisher databases

September 12, 2018 by

In this data-driven era, replication is often a critical requirement for achieving a modern, agile database management environment. It is believed designing an enterprise-grade dataset is the to achieving this requirement but building datamarts from datasets always presents certain challenges

In this article, we’ll discuss what it takes to setup “central subscriber with multiple publishers” replication model, to create an aggregate dataset from multiple sources, and you’ll also see how to scale with the data.

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Prashanth Jayaram

SQL Server replication: Overview of components and topography

September 11, 2018 by

The volume of data retained, managed, and accessed today is unprecedented. Businesses expect the IT department to keep data online and accessible indefinitely, putting intense pressure on the databases required to store and manage it. To meet today’s needs; we need to replace outdated and inefficient legacy processes with new, more agile techniques. SQL Server Replication is one of the techniques to accommodate such demands.

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Prashanth Jayaram

How to setup cross-platform transactional SQL Server replication for database reporting on Linux

August 31, 2018 by

In most cases, an organization can either use the existing out-of-the-box database replication features offered by their database software provider or invest in custom solutions to execute and manage database replication processes. The latter option sometimes allows greater flexibility to create data replicas across multiple types on multiple platforms.

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Prashanth Jayaram

How to setup custom SQL Server transactional replication with a central publisher and multiple subscriber databases

August 29, 2018 by

In this article, you’ll learn how to setup a simple, custom distributed database replication system.

Introduction

In general, a typical setup of transactional replication model of a central publisher with multiple subscribers includes the creation of a replica database(s) which may serve multiple purposes including:

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Prashanth Jayaram

How to continuously read Transaction log file data directly in a SQL Server database with fn_dblog and fn_dump_dblog

August 23, 2018 by

Outline

In this article, we’ll discuss how to read SQL Server transaction logs. This article should provide and insight into how the workload is being captured in the transaction log files. We are going to see how to get the transaction meta-data details and the history of the data will give us a clear idea of how the system is working and helps to decide peak usage hours, also helps to log information about who is doing what?

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Prashanth Jayaram

How to set up a DDL and DML SQL Server database transactional replication solution

August 22, 2018 by

In the article How to setup SQL Server database replication for reporting Server we discussed all about setting up a simple SQL Server transactional replication environment. In this article, we’ll simulate a more robust system that replicates faster and includes both DDL and DML statements. We’ll walk-through the steps to setup a dynamic transactional replication.

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Prashanth Jayaram

Using transactional data replication to replay and test production loads on a staging server

August 9, 2018 by

Outline

In this article, you’ll see how to simulate production loads on a test server with a “record and replay” type situation using the transaction log, batch scripting, PowerShell and a SQL Server agent job.

We’ll be walking through the scenario in the following steps

  1. Record the production load and write the transactions to disk by generating a timestamped replay script
  2. Create a batch file to automate the task at an interval of every 1 minute
  3. Create a SQL Server agent job to schedule the batch file
  4. Replay the production workload to the target/test database by running a PowerShell script to open and execute the scripts at the same interval as they were created, every 1 minute
  5. Validate the data between the source and the target databases to make sure our job works
  6. Monitor the load with a monitoring tool, solution of your choice
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Nesha Maric

Various techniques to audit SQL Server databases

July 5, 2018 by

SQL Server auditing has gone from a nice to have to a legal requirement, especially following new legislation like HIPAA and GDPR. Organizations are now tasked with auditing access to records, reporting suspicious and potentially malicious activity, forensically auditing data changes, as well are tracking login attempts, security changes and much more.

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Nesha Maric

Reading the transaction log in SQL Server – from hacks to solutions

July 3, 2018 by

The SQL Server transaction log is akin to a ‘Black box’ in an airliner. It contains all of the records of transactions made against a database. This information is a proverbial goldmine for database audits, recoveries etc but it was never meant to be exposed to end users let alone visualized in an easy to read manner nor used for DBA tasks. As such, utilizing this information can be a challenge, to say the least.

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Bojan Petrovic

How to implement error handling in SQL Server

June 15, 2018 by

Error handling overview

Error handling in SQL Server give us control over Transact-SQL code. For example when things go wrong we get a chance to do something about it and possibly make it right again. SQL Server error handling can be as simple as just logging that something happened or it could be us trying to fix an error. It can even be translating the error in SQL language because we all know how technical SQL Server error messages could get making no sense and hard to understand. Luckily we have a chance to translate those messages into something more meaningful to pass on to the users, developers, etc.

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Timothy Smith

Logging SQL Server database errors

May 15, 2018 by

We receive many database alerts with many of the alerts logging some of these same alerts or information to files or tables. What we’ve found over time is that the logging is now costing us quite a bit of resource. Our logging server (where both files and table logging are stored) has had a few outages related to conflicts from messages for other servers. We’ve considered scaling the alerting by environment type, but we’ve also considered that we may be logging too much information about our databases. In addition, since we receive so many alerts each day, it’s impossible for us to resolve them and assist with other issues that arise. What are some techniques that we can use to help us with the issue of too much logging information and too many alerts? Read more »

Prashanth Jayaram

How to set up SQL Server Log Shipping on Linux

November 13, 2017 by

Log shipping is a high-availability configuration that perhaps most of us are familiar with. It’s one of the oldest techniques wherein we ship transaction logs from a Primary database to a Secondary database. Log Shipping is still a vital feature used in case of applications that use warm standby for Disaster Recovery. We can see many articles which discuss the process of configuring Log shipping using T-SQL or SSMS.

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What is the SQL Server Virtual Log file and how to monitor it

April 26, 2017 by

Microsoft SQL Server has many important features when it comes to file structures. Generally speaking, DBAs often ignore file structures and growth configurations. More specifically, the SQL Server Log files are often left at default values and never touched, even when they begin to cause problems caused. These Log files are important and critical part of the database, especially when it comes to large systems.

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Timothy Smith

Useful DBCC log commands

June 1, 2016 by

Background

When we’re architecting or troubleshooting issues in an environment, understanding how the log is set up and its history helps us identify if improving it will carry significant impacts overall. We have some built in tools that we can use, such as DBCC LOGINFO and DBCC SQLPERF and in this tip we look at how we can use them when we’re debugging issues, designing our logs for scale, or monitoring our current setup. We also look at some ways we can retain the information these provide so that we can use this for historic measurements and benchmarking, as well as using them for potentially alerting.

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Jefferson Elias

How to take advantage of the SQL Server’s transaction log?

April 11, 2016 by

Introduction

SQL Server keeps track of all database modifications and every database transaction. This is done in a file called the transaction log or TLOG. This transaction log is particular to a SQL Server database and there is, at least, one transaction log per SQL Server database.

As explained on MSDN, the transaction log is a critical component of the database and, if there is a system failure, the transaction log might be required to bring your database back to a consistent state. The transaction log should never be deleted or moved unless you fully understand the ramifications of doing this.

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