A. Read-Write Splitting -> https://www.alibabacloud.com/help/docdetail/96047.htm?spm=a2c63.p38356.b99.57.500dc3c6Kt0QLs

B. Local Snapshot Backup -> Snapshot Backup is Cloud disk instance. Cross-region backup is Local disk instance.

C. Computing nodes and Storage totally seperated -> In the Basic Edition, your database system consists of only one primary RDS instance, and computing is separated from storage. This edition is cost-effective. https://www.alibabacloud.com/help/docdetail/48980.html?spm=a2c5t.11065259.1996646101.searchclickresult.75a932dfvCBnlt

D. Multi-Zone Deployment ->You can select the Single-zone Deployment or Multi-zone Development method. https://www.alibabacloud.com/help/docdetail/26092.htm?spm=a2c63.p38356.b99.18.118b4437l50tDl

A. PolarDB for Mysql

B. PolarDB for Postgres

C. PolarDB for SQLserver

D. PolarDB for Oracle

A. When you purchase a PolarDB cluster, you don't need to specify the storage capacity you want to purchase

B. PolarDB supports both OLTP and OLAP scenarios very well

C. The PolarDB database engine won't require you to replicate data when adding read-only nodes

D. ApsaraDB for PolarDB uses the pay-as-you-go billing method, therefore you only need to pay for the storage resources you actually use