15.00 - Java External Routine-Specific Dictionary Tables - Teradata Database

Teradata Database SQL Data Definition Language Detailed Topics

prodname
Teradata Database
vrm_release
15.00
category
Programming Reference
featnum
B035-1184-015K

Java External Routine-Specific Dictionary Tables

The system dictionary has 3 tables that are used exclusively to keep track of the JAR files and Java external procedure that are defined on your system. Those tables, and their respective purposes, are summarized in the following table.

 

Table Name

Purpose

DBC.Jar_Jar_Usage

Contains 1 row for each JAR included in the SQL-Java path of another JAR.

This is analogous to a #include directive in C and C++, where 1 JAR needs to include code from a different JAR. Therefore, if JAR A includes Jar B and Jar C, 1 row is inserted into DBC.Jar_Jar_Usage for the dependency of Jar A on Jar B, and 1 row is inserted for the dependency of Jar A on Jar C.

You can only alter the SQL-Java path for a JAR by calling the external procedure SQLJ.Alter_Java_Path(), which means that a call to SQLJ.Alter_Java_Path() is the only action that can add rows to this table.

See SQL External Routine Programming for details.

DBC.Jars

Contains 1 row for each installed JAR.

JARs can only be installed by means of a call to the SQLJ.Install_Jar() external procedure. Similarly, they can only be replaced by means of a call to the SQLJ.Replace_Jar() external procedure.

See SQL External Routine Programming for details.

DBC.Routine_Jar_Usage

Contains 1 row for each Java external procedure that names a JAR in its external Java reference string.

The table indicates the dependency of a Java external procedure on a given JAR.

See SQL External Routine Programming for details.

Columns for handling Jars also exist in the DBC.DBase, DBC.Dependency, and DBC.TVM tables. See Data Dictionary and SQL External Routine Programming for the structure of these tables and more information about their usage.

Archive and Restore operations on a database that contains objects that reference a Java external procedure always archive and restore the dictionary rows that reference the Java procedure information.