Customizing Parameters

Use the following parameters to customize the selected data source before you clone it. Configuration file parameters are included in parentheses.

General

Allow NULLs (allow_nulls)

Stores DMSII null data and data items that contain bad values (excluding keys) as NULLs in the relational database.

Set blank columns to NULL

Stores zero-length character data (that is, “”) as NULL instead of a single space. This only applies to columns that are not part of the index.

Allow NULL dates

Allows the Client to treat a single MISER date in the index as nullable.

Ignore new data sets (suppress_new_datasets)

Allows processing to continue when new data sets result from a DMSII reorganization.

Use column prefixes (use_column_prefixes)

Extends the table name prefix specified in the DATASOURCES client control table to all column names. This prefix allows you to distinguish between identically named data sets in multiple data sources. If a prefix isn't defined, this setting has no effect.

DMSII related parameters

Check key changes (check_key_changes)

This parameter is always selected. The DATABridge Client registers the keys of the index with the DATABridge Server, which causes the DATABridge Engine to check if the key values have changed. If the key values haven't changed, DATABridge Engine sends the update to the Client as a MODIFY record. If the keys have changed, DATABridge Engine sends the update as a BI/AI pair, which causes the Client to do a delete/insert.

Enable DMSII links (enable_dms_links)

Allows DATABridge to implement DMSII links. DMSII links are implemented using AA values as foreign keys. To use this parameter, you must set the DBEngine Links parameter to True. For more information, see the DATABridge Host Administrator's Guide.

Extract embedded data sets (extract_embedded)

Embedded data sets are not normally handled by the DATABridge Engine when INDEPENDENTTRANS is False, as the client cannot apply fixups or updates. When this parameter is selected, the Client enables a DBEngine parameter that causes the DBEngine to go through the data extraction process for embedded data sets that cannot be tracked and updated. When this parameter is unselected, DATABridge Client ignores embedded data sets. If INDEPENDENTTRANS is True, the DATABridge Client can clone and update embedded data sets regardless of this parameter.

Track Variable Format data sets (track_vfds_nolinks)

Tracks variable-format data sets that contain links. The links themselves are not tracked or updated. When a record is created in a variable-format data set, links are set to null. If the application assigns the links to point to other records, the client database will not contain these new link values until the variable-format data set is recloned. This parameter is selected, by default.

When this parameter is unselected, variable-format data sets are set to mode 11 after initial cloning and not updated.

Read NULL record values (read_null_records)

Requests NULL VALUES for data set records from DBEngine during the define/redefine commands. NULL VALUES are stored in a binary file (datasource_NullRec.dat) and are retrieved at the beginning of a process or a clone command. To indicate that data is NULL, high values (all bits set to 1) are used for numeric data and low values (all bits set to 0) are used for character data. When enabled, testing for NULL is more accurate. However, this feature adds some overhead, particularly for large databases where these records use more memory.

MISER database (miser_database)

Select this parameter when running DATABridge at a MISER database site. When selected, this parameter sets the default data format to a MISER date and additional parameters that are required for a MISER site (if not aren't already set): Flatten all OCCURS; Automated virtual data sets; Suppress duplicate (insert) warnings.

AA Values and RSNs

Use these options to specify how to represent absolute address (AA) values and (record sequence numbers) RSNs. RSNs are unique serial numbers that get assigned to records when they get created and remain associated with the record for the life of the record. (You must explicitly enable RSNs in the DASDL.) These options don't affect anything as implied by their descriptions. However, they cause the data sets option (ds_option) bits to be set when the data set record is created or when the data source is customized.

Use binary AA Values (use_binary_aa)

Represents AA values (including RSNs, Parent_AA values and DMSII Links) as binary data, which reduces the storage requirement by half. Instead of using 12 bytes, which is typically required by character data, these values are stored using 6 bytes: binary(6) for SQL Server and DB2; or raw(6) for Oracle.

Use character AA Values

Represents AA Values as CHAR(12), where each character is the hexadecimal representation of the corresponding digit (half-byte) in the A-Series word.

Use decimal AA Values (use_decimal_aa)

Represents AA values, Parent_AA values, RSNs and DMSII LINKS as a numeric data type instead of char(12). The data type varies from database to database. For SQL Server, depending on the setting of the user_bigint parameter, either BIGINT or DECIMAL(15) is used. For Oracle, NUMBER(15) is used. For DB2, DECIMAL(15) is used.