WHAT IS DBCC CHECKDB?
The command Dbcc stands for Database Console Command which is used to check the logical and physical integrity of all the objects in the specified database. It also checks for catalog consistency within the database. If corruption has occurred in the database for any reason, the DBCC CHECKDB command will find it, and tell you exactly where the problem is. It is categorized into four parts: Maintenance, Miscellaneous, Informational, and Validation.
WHY RUN DBCC CHECKDB COMMAND?
The command DBCC CHECKDB need to be run for large databases to check the consistency of the database.It is used to recover your database by using various recover options which we have discussed further. The various Recover options of DBCC CHECKDB we can use to repair our database are as follows:
1. REPAIR_REBUILD - This command checks the integrity of the table with respect to pages and structures and repairs it with no possible loss.This repair does not perform any data loss.This argument does not repair errors involving FILESTREAM data.
2. REPAIR_ALLOW_DATA_LOSS -It tries to repair all reported errors. It fixes the corrupted database structures, results in data loss. It may also involve deallocating a row, page or series of page to clear the error.
3. REPAIR_FAST -It does minor fast repairs on the database without any risk of data loss such as repairing extra keys in non clustered indexes. These repairs can be done quickly.
Warning: Choose REPAIR_ALLOW_DATA_LOSS for recovery as the last option, as it is the minimum repair level for the error found by DBCC CHECKDB, results in data loss.
USES OF DBCC CHECKDB IN SQL SERVER
- It is used to check the logical consistency of Indexes.
- If any corruption is detected, the command will raise an error, and highlight the problem.
- It is used to check the Data Page Offset, Structural content of the data and index pages.
- It is used to repair the high level of database corruption.
- It checks the consistency error of the database.
HOW TO USE DBCC CHECKDB COMMAND?
Running DBCC CHECKDB is as simple as this. You can use it by entering this simple command:
>DBCC CHECKDB (Database Name)
HOW DBCC CHECKDB WORKS:
The main function of DBCC CHECKDB is to check the logical and physical integrity of the database. For memory-optimized tables, there are no repair options, so you must take backup of your databases regularly and test it to ensure it’s integrity. If data corruption issues occur in a memory-optimized table, then you must restore the backup from the last known good backup. To check the functionality of your database ,you can perform the following operations to check the integrity:
- Perform DBCC CHECKALLOC on the database.
- Perform DBCC CHECKTABLE on every database object like table and views.
- Perform DBCC CHECKCATALOG on the database.
- Verify the integrity of every indexed view of a specific database.
ALTERNATIVE TO DBCC CHECKDB:
Every company wants to ensure the database integrity of their database system. If you are not checking the consistency of database on a regular basis, then your databases might have corruption without your knowledge. You can check various repair options available with DBCC CHECKDB which are as follows:
Although these commands are highly supported, but sometimes it is not always considered as the best option for bringing the database to a consistent state. If the command is successful, it will sometime result in the loss of data. Executing these syntaxes may result in considerable amount of data loss. If these repair commands involves loss of data, it is recommended to keep it at the end of the list in repair operation and use alternative option.
The data loss caused and to improve the consistency of the database, we can use the alternative professional tool name SQL Repair Tool. One major benefit that the tool offers is that it can recover data of MDF and NDF files.
BENEFITS OF USING SQL DATABASE REPAIR TOOL:
- It is used to recover Deleted SQL Server Database table’s Data.
- It can scan & recover multiple NDF Files (Secondary Database)
- It can export file into SQL Server Database or as SQL Server Compatible Scripts using SQL Database Repair Tool.
- It can scan & recover Triggers, Rules, Functions, Tables, Stored Procedures.
- This tool provide Quick & Advanced Scan To Repair SQL Database file : Both Primary & Secondary.
- The best part of this tool is it support ASCII and Unicode XML datatype.
- It can be used to recover the database files of version 2016 and below.
In the end,DBCC CHECKDB command is used to ensure the logical and physical data integrity. We must set DBCC CHECKDB task on our SQL Server. This way you will be able to detect the corrupted database. If data corruption has happened, then you can take immediate action by using REPAIR commands or by using an alternate option and protect your database from the data loss. Without this corruption check, you might not discover the problem until it’s too late.
This post first appeared on SQL Server Technical Updates And Solutions, please read the originial post: here