Compression

Dictionary Encoding Bit Packing / Mostly Encoding Prefix Compression

Same as in (Microsoft SQL Server).

Concurrency Control

Multi-version Concurrency Control (MVCC) Two-Phase Locking (Deadlock Prevention)

Same as in (Microsoft SQL Server).

Indexes

B+Tree Hash Table

Refer to (Microsoft SQL Server). Along with the indexes provided from the SQL Server codebase, Azure SQL Database produces recommendations for ADD/DROP INDEX in order to optimize its plans. It does this by monitoring the performance of queries across all SQL Database instances on the Azure cloud. It performance statistics of queries across all databases to develop models to estimate performance gains on a non-existent index for a certain query in a database instance. These estimates are used to create recommendations for adding and dropping indexes and the application can choose to automatically have these recommendations applied.

Foreign Keys

Supported

Same as in (Microsoft SQL Server).

Checkpoints

Non-Blocking Consistent Fuzzy

Same as in (Microsoft SQL Server).

Storage Organization

Log-structured

Joins

Nested Loop Join Hash Join Sort-Merge Join

Same as in (Microsoft SQL Server).

Isolation Levels

Read Uncommitted Read Committed Serializable Snapshot Isolation Repeatable Read

Same as in (Microsoft SQL Server).

System Architecture

Shared-Disk

There are three main types of deployment for this cloud database service.

Logging

Physical Logging

Data Model

Relational

Storage Model

N-ary Storage Model (Row/Record)