Three SQL Server recovery models: simple, full, bulk-logged recovery model

EaseUS Todo Backup supports three SQL 2012/2008/2005/2016 recovery models: simple, full, bulk-logged recovery model.

  Free Download

For All Windows PCs and Servers

100% Secure
Updated by Jean on Feb 22, 2023
Written by Tracy King

SQL Recovery Models Detailed Information
Simple Recovery Model SQL Server maintains only a minimal amount of information in the transaction log...Full steps
Full Recovery Model With the full recovery model, SQL Server preserves the transaction log until you back it up...Full steps
Bulk-logged Recovery Model The bulk-logged recovery model is a special-purpose model that works in a similar manner...Full steps

There are THREE different recovery models of SQL Server, you should select SQL Server recovery model to manage log files and prepare for the SQL recovery in case of disaster. This document is to talk about three SQL Server recovery models: simple, full and bulk-logged. Among all, you should back up your SQL Server database.

This document recommends reliable SQL Server database backup and recovery software: EaseUS Todo Backup.

  Free Download

For All Windows PCs and Servers

Basic Information About Log Files

SQL Server database contains at least an MDF data file and an ldf log file. Mdf file contains all the database objects and data, such as the table, stored procedure, and user information. Ldf log file contains all logs in the database. While, you never only count on log files to recover your database, for example, to recover the database to some time-point through the ldf log file and the previous full backup.

What does the log file do?

  • Being physical store position of logs, we can back up the logs from the ldf log file, and recover the database using log backup file.
  • SQL Server will read the log from ldf log file every time it launches. It will roll back up affairs not submitted before and roll forward those affairs which have been submitted but not have been written data file to ensure the integrity of affairs.
  • A full backup contains all data of the database but does not include all logs. Full backup only contains all data pages and logs in the tail of the current database.

Activity log means log records of current running affairs. A virtual log means a logic storage unit of the log. SQL Server logically divides ldf log file space into several pieces. Every piece is a virtual log. Log truncation means to delete the former log.

Simple Recovery Model

When you choose the simple recovery model, SQL Server maintains only a minimal amount of information in the transaction log. SQL Server truncates the transaction log each time the database reaches a transaction checkpoint, leaving no log entries for disaster recovery purposes.

In databases using the simple recovery model, you may restore full or differential backups only. It is not possible to restore such a database to a given point in time, you may only restore it to the exact time when a full or differential backup occurred. Therefore, you will automatically lose any data modifications made between the time of the most recent full/differential backup and the time of the failure.

Simple Recovery requires the least administration. It is easier to manage than the Full or Bulk-Logged models, but at the expense of higher data loss exposure if a data file is damaged. Simple Recovery is not an appropriate choice for production systems where loss of recent changes is unacceptable. When using Simple Recovery, the backup interval should be long enough to keep the backup overhead from affecting production work, yet short enough to prevent the loss of significant amounts of data.

  • Advantage: permits high-performance bulk copy operations. Reclaims log space to keep space requirements small.
  • Disadvantage: changes since the most recent database or differential backup must be redone.

Full Recovery Model

With the full recovery model, SQL Server preserves the transaction log until you back it up. This allows you to design a disaster recovery plan that includes a combination of full and differential database backups in conjunction with transaction log backups.

You have the most flexibility restoring databases using the full recovery model when a database failure happens. In addition to preserving data modifications stored in the transaction log, the full recovery model allows you to restore a database to a specific point in time.

  • Advantage: no work is lost due to a lost or damaged data file. It can recover to an arbitrary point in time.
  • Disadvantage: if the log is damaged, changes since the most recent log backup must be redone.

Bulk-logged Recovery Model

The bulk-logged recovery model is a special-purpose model that works in a similar manner to the full recovery model. The only difference is in the way it handles bulk data modification operations. The bulk-logged model records these operations in the transaction log using a technique known as minimal logging. This saves significantly on processing time but prevents you from using the point-in-time restore option.

  • Advantage: permits high-performance bulk copy operations, minimal log space is used by bulk operations.
  • Disadvantage: if the log is damaged, or bulk operations occurred since the most recent log backup, changes since that last backup must be redone.

Full Recovery and Bulk-Logged Recovery models provide the greatest protection for data. These models rely on the transaction log to provide full recoverability and to prevent work loss in the broadest range of failure scenarios. The Bulk-Logged model provides higher performance and lower log space consumption for certain large-scale operations.

When you choose different MS SQL Server backup strategies, you will have specific limitations to recover SQL Server backups.

Was This Page Helpful?

Updated by Jean

Since graduating from university, Jean has been writing tech articles and has been a valuable member of the EaseUS team for over 5 years. Her areas of expertise include data recovery, disk partitioning, data backup, and multimedia world.

Read full bio

Written by Tracy King

Tracy joined in EaseUS in 2013 and has been working with EaseUS content team for over 10 years. Being enthusiastic in computing and technology, she writes tech how-to articles and share technical solutions to resolve Windows & Mac data recovery, data backup, partition management, data transfer, Windows update issues, etc.

Read full bio

Product Reviews

TrustScore 4.7 | 47 reviews
  • Taking everything into consideration, we can say that EaseUS Todo Backup Home can offer you a little extra sense of security with a set of advanced tools. The interface provides quick adaptation, every process guiding you all the way through so you don't get stuck or further damage your system rather than keeping it safe.

    Read More
  • EaseUS Todo Backup Free lets you create backups of your important files or your entire computer through its streamlined interface. Just choose the backup type you'd like to get started, and let the program do the reset.

    Read More
  • EaseUS includes all the features I expect from backup software like versioning, incremental backups, and scheduling. For more advanced users, EaseUS allows you to install a pre-boot environment onto your hard drive so you can use it to restore files without burning a CD or putting it on an external USB drive.

    Read More

logo

EaseUS Todo Backup

Smart backup tool for your files and entire computer in Windows 10/8/7.

Product Reviews

Install Windows on Multiple Computers at Once? No Problem!

Learn how to install Windows 11/10/7 and special programs/software on a batch of computers. Use 10 minutes to do the 10 hours work without making a single mistake!

Get Free Solution!