Net.Data Administration and Programming Guide for OS/400

Configuration Variable Statements

Net.Data configuration variable statements set the values of configuration variables. Configuration variables are used for various purposes. Some variables are required by a language environment to work properly or to operate in an alternate mode. Other variables control the character encoding or content of the Web page being constructed. Additionally, you can use configuration variable statements to define application-specific variables.

The configuration variables you use depend on the language environments you are using, as well as other factors that are specific to the application.

To update the configuration variable statements:

Customize the initialization file with the configuration variables that are required for your application. A configuration variable has the following syntax:

NAME[=]value-string

The equal sign is optional, as denoted by the brackets.

The following sub-sections describe the configuration variables statements, used by Net.Data-supplied language environments, that you can specify in the initialization file:

• DTW_SQL_ISOLATION: DB2 Isolation Variable

• DTW_SQL_NAMING_MODE: SQL Table Naming Variable

• DTWR_CLOSE_REGISTRIES: Open Web Registry Variable

DTW_SQL_ISOLATION: DB2 Isolation Variable

The DTW_SQL language environment uses the DTW_SQL_ISOLATION configuration statement to determine the degree to which the database operations executed by the DTW_SQL language environment are isolated from concurrently executing processes.

Syntax:

DTW_SQL_ISOLATION locking_method

Where locking_method is one of the following values:

DTW_SQL_NO_COMMIT

Specifies not to use commitment control. For the OS/400 operating system, do not specify this value if a relational database is specified in the relational database directory and the relational database is on a non-OS/400 system.

DTW_SQL_READ_UNCOMMITTED

Specifies locking for the objects referred to in SQL ALTER, COMMENT ON, CREATE, DROP, GRANT, LABEL ON, and REVOKE statements and the rows updated, deleted, and inserted. The objects are locked until the end of the unit of work (transaction). Uncommitted changes in other processes can be seen.

DTW_SQL_READ_COMMITTED

Specifies locking for the objects referred to in SQL ALTER, COMMENT ON, CREATE, DROP, GRANT, LABEL ON, and REVOKE statements and the rows updated, deleted, and inserted. The objects are locked until the end of the unit of work (transaction). A row that is selected, but not updated, is locked until the next row is selected. Uncommitted changes in other processes cannot be seen.

DTW_SQL_REPEATABLE_READ

Specifies locking for the objects referred to in SQL ALTER, COMMENT ON, CREATE, DROP, GRANT, LABEL ON, and REVOKE statements and the rows selected, updated, deleted, and inserted. The objects are locked until the end of the unit of work (transaction). Uncommitted changes in other processes cannot be seen.

DTW_SQL_SERIALIZABLE

Specifies locking for the objects referred to in SQL ALTER, COMMENT ON, CREATE, DROP, GRANT, LABEL ON, and REVOKE statements and the rows selected, updated, deleted, and inserted. The objects are locked until the end of the unit of work (transaction). Uncommitted changes in other processes cannot be seen. All tables referred to in SELECT, UPDATE, DELETE, and INSERT statements are locked exclusively until the end of the unit of work (transaction).

DTW_SQL_NAMING_MODE: SQL Table Naming Variable

The DTW_SQL_NAMING_MODE configuration statement specifies how a table name can be specified in an SQL statement.

Syntax:

DTW_SQL_NAMING_MODE mode

Where mode is one of the following values:

SQL_NAMING

Specifies that tables are qualified by the collection name in the form:

collection.table

where collection is the name of the collection and table is the table name. The default qualifier is the user ID running the process that executes the SQL statement and is used when the table name is not explicitly qualified and the default collection name is not specified. SQL_NAMING is the default table name.

SYS_NAMING

Specifies that files are qualified by library name in the form:

library/file

where library is the name of the library and file is the table name. The default search path is the library list (*LIBL) for the unqualified table name, if the table name (file) is not explicitly qualified and a default collection name (library) is not specified.

DTWR_CLOSE_REGISTRIES: Open Web Registry Variable

Specifies whether to close or keep a Web registry open. This variable lets you keep the Web registry open so that subsequent invocations of Net.Data macros that access the same Registry do not have to reopen the registry.

Syntax:

DTWR_CLOSE_REGISTRIES YES|NO

Where:

YES

Specifies to close all open Web registries after a Net.Data macro has been processed.

NO

Specifies to leave all open Web registries open after a Net.Data macro has been processed. NO is the default.

Performance tip: You can use the DTWR_CLOSE_REGISTRIES configuration statement to improve the performance of accessing a Web registry (with the Web registry built-in functions) by minimizing the opening and closing of registries.