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A simple comparison of database mirroring and replication

青灯夜游
青灯夜游Original
2019-03-02 16:34:105106browse

Mirroring and replication are terms related to data replication in DBMS, so what is the difference between them? The following article will give you a brief comparison of mirroring and replication in the database. I hope it will be helpful to you.

A simple comparison of database mirroring and replication

What is database mirroring?

Database mirroring refers to the technology of creating and maintaining redundant copies of a database. The mirror copies are always synchronized with the principal database; these database copies are usually located on different machines. This technology helps ensure uninterrupted data availability and also reduces downtime due to data corruption or loss.

It can create a copy of the database in two different server instances (principal and mirror). These mirror copies work as standby copies and are not always active like data replication.

If any failure occurs, it can recover the data by copying it from one database to another. In the event of any failover, the mirror database becomes the primary database.

What is database replication?

Database replication refers to the technology of copying data and distributing these copies from one database to another.

In replication, data and database objects are copied and distributed from one database to another. It reduces the load on the original database server because clients can use multiple servers; and all servers replicating the database are as active as the primary server. To maintain consistency between data and database objects, the database is also synchronized.

This technique can be used to replicate data across multiple databases. Partial replication is only implemented for a subset of the columns of a table or rows, so it essentially does not replicate the entire database.

Key differences between replication and mirroring:

1. A mirror database can usually be found on a different machine than its primary database. Instead, the replicated data and database objects are stored in another database.

2. Mirroring does not support distributed environments, while replication is designed for distributed databases.

3. The cost of database mirroring is higher than replication.

Replication and mirroring technologies can also be used in combination to achieve higher database availability. The above is the entire content of this article, I hope it will be helpful to everyone's study. For more exciting content, you can pay attention to the relevant tutorial columns of the PHP Chinese website! ! !

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