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Database-side JDBC routines and nested connections
Most database-side JDBC routines need to share the same transaction
space as the statements that called them.
The reasons for this are:
- to avoid blocking and deadlocks
- to ensure that any updates done from within the routine are atomic with
the outer transaction
In order to use the same transaction, the routine must use the same connection
as the parent SQL statement in which the routine was executed. Connections
re-used in this way are called nested connections.
Use the connection URL jdbc:default:connection to re-use the current Connection.
The database donnection URL jdbc:default:connection allows a Java method
to get the Connection of the SQL statement that called it. This is
the standard (SQL standard, Part 13, SQL Routines and Java) mechanism to obtain
the nested connection object. The method would get a Connection
as follows:
Connection conn = DriverManager.getConnection(
"jdbc:default:connection");
URL attributes are not supported as part of this connection URL. Any URL
attributes specified in a Properties object, user name, or password that are
passed to a java.sql.DriverManager.getConnection() call will be ignored.
Loading a JDBC driver in a database-side routine is not required.
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