Advanced Parameters (Customizing)

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

Global data set options

Clear duplicate records encountered during data extraction (clr_dup_extr_recs)

Removes false duplicate records caused by long cloning of an active DMSII database, allowing the index creation and fixup phases to continue. If false duplicate records aren't manually removed, index creation fails. This parameter globally sets the ds_options bit that corresponds to the data set property Clear Duplicate Extract Records for all DATASETS table entries.

Force AA Values as indexes (force_aa_value_only)

Do not force let's the Databridge Engine decide when to use AA values. Always force forces the define and redefine commands to use AA values as the index, even if the data set has a SET that qualifies for use as an index. Force only if RSN forces the define and redefine commands to use RSN values (when they exist) as the index. This parameter globally sets the ds_options bit that corresponds to the data set property Use AA Values (or RSNs) as Keys for the DATASETS table entries.

Ignore new columns (suppress_new_columns)

When this parameter is set to true, the redefine command sets the active column to 0 for new DATAITEMS and DATATABLES entries associated with the reorganization. If you later decide that you want to include such columns, you must disable this parameter and run a Redefine command by clicking Data Source > Advanced> Redefine (with options) and checking the Redefine All Data Sets option, unless you are using the Client configurator.

Update changed columns only (minimize_col_updates)

The checkbox Update changed column only specifies whether the define or redefine command should set the DSOPT_Optimize_4_CDC bit (value 0x80000) in the ds_options field of the DATASETS table. This bit indicates that client will only update columns whose values have changed. To do this, stored on procedures are abandoned in favor of pure SQL without the use of host variables. This usually slows the update speed of the Client, but when using SQL Server or Oracle replication, the overall process ultimately takes less time because significantly less data is sent to the remote database during the replication.

Optimize SQL updates (optimize_updates)

Eliminates all redundant updates. Use this option when the number of occurrences for items is very large and you are not flattening the OCCURS clauses. An OCCURS clause is a DMSII construct that describes the number of times an item is present in a data set. This parameter globally sets the ds_options bit that corresponds to the data set property Optimize SQL Updates for all DATASETS table entries.

Split variable format data sets (split_varfmt_dataset)

This option provides an alternate way for mapping variable format data sets to tables in the relational database. The fixed parts of all variable format records are stored in the table for type 0 records. The variable parts of the records and keys are stored in tables for other types of records.

The client normally stores each record type in a table whose name is the data set name (in lower with all dashed changed to underscores) followed by "_type nnn" (where nnn is the variable format record type). The table for type 0 records, which have no variable part, does not have a suffix like the tables for all other record types.

This parameter globally sets the ds_options bit that corresponds to the data set property Split variable format data sets for all DATASETS table entries.

When this option is disabled, each individual record type in the variable data set is mapped to a separate secondary table.

Use stored procedures in updates (use_stored_procs)

This parameter makes the process and clone commands generate the actual SQL command instead of a stored procedure call to perform an update. The Client still uses host variables, as was the case with stored procedures calls. Executing the SQL directly eliminates some overhead and makes processing the update faster. On exit from the Client Configurator, the Client Console command will ask you to run a reorg command, which creates a new set of scripts for creating the tables. It also will refresh the stored procedures for all data sets by dropping them if they exist and are no longer needed, or by recreating them if they are needed.

Table layout

Flatten all OCCURS (flatten_all_occurs)

Creates a new column in the primary table for each OCCURS item. Enable this parameter if the DMSII data contains a lot of OCCURS clauses that you want to flatten. When this parameter is disabled, a DMSII data set that has an OCCURS clause in an item will be placed in a secondary table in the relational database. As a result, a single DMSII update can end up updating multiple tables multiple times, as each occurrence of the item is placed in a separate row in the secondary table.

Maximum columns in tables (maximum_columns)

Use this parameter to limit the maximum number of columns that can be created in split tables. Split tables are created from a data set that exceeds the maximum number of columns allowed by the relational database. For SQL Server, this number is 1024. If you set this parameter to 1000, the split will occur after 1000 columns.

Indexes

Use clustered indexes (use_clustered_index)

(SQL Server only) Enable to use clustered indexes for all tables. To override this option for a single table, disable the Use Clustered Index check box in the Relational Properties pane for the table in Client Configurator.

Use Primary Keys (use_primary_key)

Creates a primary key instead of using a unique index for all tables. To override this option for a single table, disable the Use Primary Keys check box in the Relational Properties pane for the table in Client Configurator.

Table reorganization options

Use internal clone for reorganizations (use_internal_clone)

This parameter affects the redefine and reorg commands and the Client Configurator. Instead of using ALTER commands to add, delete or modify new columns to tables, the Client uses a combination of scripts and table renaming commands to create new copies of the tables with the new layouts. The Client copies the data using SELECT INTO in the case of SQL Server and CTAS (Create Table As Select) in the case of Oracle. This operation works like the bulk loader and is sometimes faster than using ALTER and UPDATE commands, but more importantly, the command is not logged. The only drawback of this method is that it requires sufficient free disk storage to hold a second copy of the table for the duration of the operation.

Reorg command update batch size (reorg_batch_size)

This parameter determines the size of the transactions that the Client uses during a reorg command to set the value of newly-added columns to their initial values, as defined in the DASDL. The Client Configurator creates a reorg script that uses a stored procedure to do the updates in batches that are executed as transactions. For a large table, this process can take quite long, but it does not run the database out of log space. Consider using the internal clone option instead.

Do not set initial values for new columns (inhibit_init_values)Inhibits the reorg command from setting new columns to their INITILAVALUE in DMSII.