Everyone knows what the default database isolation level of MySQL is, right? Yes, it is RR. But why do major internet ...

Standard SQL defines four isolation levels that can be set using the SET TRANSACTION ISOLATION LEVEL statement: Serializable, Repeatable Read, Read Committed, and Read Uncommitted. Although all of the ...

That is not the case. What the NOLOCK hint does is enforce SQL Server's Read Uncommitted isolation level, which allows for what is known as dirty reads. What does this mean for your application?

If SPOOL=DBMS, SAS automatically sets READ_ISOLATION_LEVEL=SERIALIZABLE for ORACLE versions 7.3 or later and to READ_ONLY for prior versions. In all other cases, the default value is READCOMMITTED.

The DB2 database manager supports three isolation levels. Regardless of the isolation level, the database manager places exclusive locks on every row that is inserted, updated, or deleted. Thus, all ...