SQL Azure, frequency of DB copies and backup strategy

Question

Trying to design our DB backup strategy for SQL Azure. In the first instance transactions will be about 200/day.

Scenarios I will be protecting against is:

1) Complete DB lost, failure, corruption which is essentially covered by SQL Azure's saving to 3 point policy ie it has 1 primary and 2 secondary copies.

2) Corruption of records, by buggy code or user error. I would not want to restore a DB for this, and my current thoughts are use a DB copy from a "previous period" (maybe previous night) and do a data compare. Tool in mind is SQL Server Data Tools are used in VS.

My current thoughts are once a day over night take a DB Copy ie

Create Database as copy of liveDB

I think MS talks about a rolling 3 copy procedure, in my case 3 days of backup would be kept then copy 1 would be overwritten by copy 4.

Also do a DB Export as recommended by MS.

Thoughts?

Answer 1

Since the question was "thoughts?" here are some:

Be advised, a DB Export via the Azure managment pages produces a BACPAC which is not transactionally consistent (see http://msdn.microsoft.com/en-us/library/hh335292.aspx).

A DB Copy as you expressed above (Create Database as copy of liveDB) is transactionally consistent, but when it is finished it is billable as it will have the same edition and database size as the source database (see http://msdn.microsoft.com/en-us/library/azure/ff951631.aspx).

As JuneT mentions, using an Automated Export is transactionally consistent, because it first creates a DB Copy, then does a DB Export. Because databases are billed in increments of a day no matter how long the copy is online, if you had a daily backup, you would be paying double the cost of your source database because of the copy coming online before the BACPAC is produced. Once the BACPAC is produced the copy is no longer needed by Automated Export, but you'll still be charged for a prorated day of use. Your retention settings will also impact billing as it relates to storage accounts since you'll be paying for stored BACPACs in terms of their size.

see http://blogs.msdn.com/b/sql-bi-sap-cloud-crm_all_in_one_place/archive/2013/07/24/sql-azure-automated-database-export.aspx
and
http://msdn.microsoft.com/library/azure/ee621788.aspx

Answer 2

SQL Azure has a built-in feature for restoring from this sort of issue: see http://msdn.microsoft.com/en-us/library/hh852669.aspx All Azure SQL Databases are automatically backed up, and the recovery options vary based on the edition of the database. Basic databases allow you to restore the database back to a its state when it was last backed up (once per 24 hours). Standard and Premium edition databases allow restore to any point in time.