Stéphane Nicoll opened SPR-15255 and commented

See this spring boot issue

When the Database is set to SQL_SERVER, HibernateJpaVendorAdapter#determineDatabaseDialectClass sets the dialect to org.hibernate.dialect.SQLServerDialect. However there are multiple flavours of that dialect:

Microsoft SQL Server 2000	org.hibernate.dialect.SQLServerDialect
Microsoft SQL Server 2005	org.hibernate.dialect.SQLServer2005Dialect
Microsoft SQL Server 2008	org.hibernate.dialect.SQLServer2008Dialect

Ironically enough, if we don't see the dialect, Hibernate manages to detect the right one (in this particular case at least).

Should we consider stopping providing a dialect for SQL Server since we can't know which database is in use?

Affects: 4.3.6

Issue Links:

• Default connection release mode inconsistent with Hibernate 5.1.1 [SPR-14548] #19116 Default connection release mode inconsistent with Hibernate 5.1.1
• Support for read-only transactions with Oracle 12c JDBC driver [SPR-15210] #19774 Support for read-only transactions with Oracle 12c JDBC driver
• Remove native support for Hibernate 3.6 and 4.x [SPR-13827] #18400 Remove native support for Hibernate 3.6 and 4.x

Referenced from: commits 7ed4884