Databases Reference
In-Depth Information
•
Maximum number of databases.
You can create no more than one hundred and fifty user
databases.
•
Distributed transactions.
Although SQL transactions are supported, distributed transactions
aren't supported across SQL Database instances.
•
Collation.
SQL Database supports collation at the column and database levels, or using an
expression at execution time. Server- level collations can't be changed and are set to
SQL_
LATIN1_GENERAL_CP1_CI_AS
. Once set at the database level, the collation cannot be changed
using the
ALTER DATABASE
command.
•
English language.
SQL Database only supports the English language.
•
Database size.
You can only create databases of specific sizes, as outlined previously.
•
Row Versioning-Based Isolation Levels.
READ_COMMITTED_SNAPSHOT
and
ALLOW_SNAPSHOT_
ISOLATION
options are set at the database level, and cannot be changed.
•
Database file placement.
You can't choose how the database files are deployed physically;
you can't control filegroups, either. This is handled automatically by the Microsoft data center
for optimum performance.
•
Trace flags.
Trace flags aren't available.
•
SQL Server configuration options.
None of the general SQL Server options are available,
including CPU and I/O affinity.
•
Service Broker.
The Service Broker isn't available.
•
Global temporary tables.
The global temporary tables aren't available. However, you can use
local temporary tables.
•
SQL Server Agent.
The SQL Server Agent isn't available.
Drivers and Protocols
You should also know that accessing SQL Database can only be performed using specific libraries. This may be
relevant if you don't use ADO.NET in your programming stack. For example, older versions of Delphi can't connect
to SQL Database. Here is a summary of the supported data libraries:
•
TDS version 7.3 or higher.
Any client using a TDS version prior to 7.3 isn't supported.
•
Drivers and libraries.
The following drivers and libraries are allowed:
•
.NET Framework Data Provider for SQL Server from.NET 3.5 SP1
•
SQL Server 2008 Native Client ODBC driver or higher
•
SQL Server 2008 driver for PHP version 1.1 or higher
Summary
This chapter focused on a fast-track overview of SQL Database by providing a high-level introduction to cloud
computing and how Microsoft is delivering its cloud offering. You also learned the major steps involved in creating an
Azure account and how to get started with SQL Database. You saw some important limitations of the SQL Database
platform, but keep in mind that Microsoft is releasing new versions of its cloud database every few months; as a result,
some of these limitations will be lifted over time.
