Comparison of several read/write separation schemes for SQL Server

We often encounter this situation in a production environment:

The front-end OLTP business is busy, but these operational data need to be OLAP, in order to not affect the front-end normal business, so the database needs to be read-write separation.

Here I will be a few can be used to read and write separation of the program summary, the scheme itself is not good or bad, only to see whether it is suitable for business use scene, so only a few of the characteristics of the program listed, encountered specific problems in accordance with their own needs and environmental comprehensive consideration after the trade-offs

Read-Write separation scheme	Real-time synchronization	Whether the copy data is directly readable	Number of replicas	Minimum grain size	Copy indexing	Environment	Disadvantages
Mirror	Is	No (need to open snapshot, read only)	1	Library	Whether	Domain/non-domain (using certificates)	In high-safety mode for the main library Performance has a certain impact
Log shipping	Whether	Yes (read only)	N	Library	Whether	UNC way to access	Replica library disconnects connected users when doing resotre/may affect regular log backups
Publish a subscription	Is	Yes (read and write, but write may result in inconsistent data)	N	Table (query)	Is	Domain/non-domain	When there is a large number of DML operations on the main library , there is a certain impact on the Distributor, and the subscription database may have data synchronization delays
Always on	Is	Yes (read only)	4 (SQL 2012) 8 (SQL 2014)	Library	Whether	Domain	Non-domain environment is not available

Comparison of several read/write separation schemes for SQL Server