SQL Server misunderstanding 30th talk about the 7th day multiple mirroring and log shipping latency for one instance _mssql

Myth #7: Multiple mirrors can exist for a database

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This myth is a bit of a cliché. Only one mirror server is allowed per principal server. If you want to have copies of multiple principal servers, use transaction log shipping, which allows multiple secondary instances to exist for each principal.

One advantage of using transaction log shipping is to allow one or more secondary servers to have a deferred restore backup. This also means that log backups of the principal server (whether you like it or not, each of these high-availability technologies has its own terminology):

Database mirroring: Principal server-mirror server
Transaction log Shipping: Primary server-Secondary server
Replication: Publishers-Subscribers


When mirroring is used, when you drop a table from the principal server, the table is also dropped on the mirror server (even if there is a delay, you cannot cancel the operation). However, if it is a 8-hour delay transaction log shipping mode, drop the table on the primary server, the table will still be accessible to the secondary server until the log takes effect after 8 hours.

By the way, Sqlcat team wrote an article, for an example, you can only mirror 10 databases, the article is as follows: Mirroring a Large number of Databases in a single SQL Server instance to And another article I wrote about this topic: KB 2001270 Things to consider when setting up database mirroring in SQL Server.