Skip to main content

SQL Server Backups

1. Full Backup:

This is the most common and simplest back up method, It contains all the data in a specific database and enough log that is required to recover the database. It is the base of both differential back up and transaction log back up.

2. Differential Backup:

It depend on the latest full backup of data. It contains all the changes that have been made since the last full backup of data. 

3. Transaction Log Backup:

The transaction log is a record of  all the transactions that have been performed against the database since the last transaction log backup. That means it includes all log records that were not backed up in the last transaction log. With transaction log backup you can recover the database to a specific point of time. This SQL Server backup type is possible only with full or bulk-logged recovery model.

4. File and File group Backup:

This backup type allows you to backup one or more database file or file groups. 

5.Partial Backup:

This type of backup is similar to full database backup, but it does not contain all the file groups.This allows you to backup the PRIMARY filegroup, all Read-Write filegroups and any optionally specified files.  This is a good option if you have Read-Only filegroups in the database and do not want to backup the entire database all of the time.
Labels:

Comments

Post a Comment

Popular posts from this blog

Interview Questions and Answers on SQL Server View

    W hat is a View?        Views are virtual tables that hold data from one or more tables. It is a query stored in the database as object. A view does not contain any data itself, it is a set of queries that are applied to one or more tables that are stored within the database as an object   What is the use of view? It allows you to reuse code without  having to write the same complex SQL code over and over. Views are used for security purposes in databases. Views restrict the user from viewing certain columns and rows. In other words, using a view we can apply the restriction on accessing specific rows and columns for a specific user  Can we use ORDER BY clause inside a view?   The ORDER BY clause is invalid in views, inline functions, derived tables, subqueries, and common table expressions, unless TOP or FOR XML is specified. Can we update a view?       If the view contains joins between mult...
Post a Comment
Read more

SQL Server- CHAR,VARCHAR, NVARCHAR

SQL Server String Data Types CHAR CHAR is a fixed data type. So when a column is declared as CHAR, irrespective of  the actual characters stored in that variable/column, it will use all the declared space. In the above example you can see that even though the actual length of the variable is 6, It occupies 30 bytes of space.This is because when the variable @name is declared as CHAR(30), 30 bytes of space got reserved for the variable.  Also, you can observe that CHAR type column uses 1 byte of space to store each character. Summary: 1. It is a fixed data type 2. Occupies 1 byte of space for each character 3. It is used to store non-unicode character. VARCHAR VARCHAR is a variable length data type. So when a variable or column is declared as VARCHAR, irrespective of declared space, it will use only space require to store all characters. In the above example you can see that even though the declare...
Post a Comment
Read more

SQL Server difference between DELETE, TRUNCATE, DROP

DELETE DELETE removes some specific rows (with WHERE clause) or all rows (without WHERE clause) The operation can be rolled back.    DELETE is a DML command. This operation cause all DELETE triggers on table to fire. Conditions like WHERE clause can be used. Note: when we issue a DELETE command then all data get copied into ROLLBACK Tablespace first. Then delete operation get performed. That is why when you type ROLLBACK after deleting table, you can get back the data (The system get it for you from the Rollback Tablespace) TRUNCATE TRUNCATE removes all rows from a table. The operation cannot be rolled back. TRUNCATE is a DDL command. No triggers will be fired. Conditions like WHERE clause cannot be used with it. TRUNCATE is faster than DELETE. Note: when you issue a TRUNCATE command, it removes data directly without copying it into the Rollback Tablespace. So it is faster than DELETE. Also because of the same reason the data dele...
Post a Comment
Read more