I'm migrating my Sitecore DBs from a local installation to Azure PaaS SQL instances using SSMS. I've successfully migrated Core, Master, Web and, with a small edit, Session. I'm having problems with the Analytics database. Even after it fails, Sitecore seems to still work fine with the database, but I'm sure there are unseen consequences.
What is the Analytics db used for? Do I need it if I'm using MongoDB for xDB?
The Analytics DB is used as a reporting database for xDB. MongoDB is the collection database and periodically this is aggregated and stored in the Analytics db (also called the reporting db).
If you have xDB and Tracking disabled, then you will not need the Analytics DB. IF you are using xDB and want to be able to view all the reports etc... then you will need it.
Sitecore will work OK either way without it. But you may get errors in your log file if xDB is enabled. The aggregation services will fail, and you will not be able to view the reports properly.
Just adding to Richard Seal's answer that you can rebuild the contents of the SQL reporting database, as documented here.
As the documentation notes:
The Sitecore Experience Database (xDB) uses two database systems (SQL Server and MongoDB) that need to be kept in sync to provide accurate data for Sitecore reporting applications:
- MongoDB collection database - stores all experience data
- SQL Server reporting database - stores aggregated reporting data
Sitecore automatically keeps these databases in sync but there are certain circumstances when you may need to perform a complete rebuild of the reporting database. For example, after you have run the Sitecore Analytics Conversion Tool and have additional historical data that you want to include in your reporting applications. There are also several other reasons for rebuilding the reporting database.
