Performing the Extract
After you define the extract (create or update a source definition), you must perform the extract (create an extract object from a source definition) to initiate the extraction process. The inputs to the extraction process are a source definition and the name of a sequential data set that rcx (CA RC/Extract) creates to hold the extract object. The source definition defines the objects to extract the data from and the rules for extracting the data. You can extract data (unload) from the tables in the source definition using SQL statements or using a load utility.
After you define the extract (create or update a source definition), you must perform the extract (create an extract object from a source definition) to initiate the extraction process. The inputs to the extraction process are a source definition and the name of a sequential data set that
CA RC/Extract™ for DB2 for z/OS(CA RC/Extract) creates to hold the extract object. The source definition defines the objects to extract the data from and the rules for extracting the data. You can extract data (unload) from the tables in the source definition using SQL statements or using a load utility.
The output of the extract process is the extract object. An extract object is a data set containing extracted data. Because of its unique structure, an extract object should not be loaded with a load utility unless CA RC/Extract generates control cards for the load. Because of this restriction, when an extraction is performed, ensure that the allocation parameters allow the data set to be permanently cataloged. The object then remains available if a load is performed at a later time.
The object's data can be browsed by ISPF. As a result, if data masking is not in use, the data might be visible to users who do not have DB2 access to the original data.
You can change the extract options as needed. You can also use the Command Center to perform an extract.
Follow these steps:
- Type1(Extract and Load DB2 Data) on the RC/EXTRACT Main Menu and press Enter.The Extract/Load Services panel appears.
- Type2(Perform Extract) and press Enter to initiate the extract process.The Process Source Definition panel appears. From this panel, you can specify the input and output of the extract process. The input is a source definition and the output is an extract object.
- Specify the following options:
- Specify an existing source definition to define the extract. Selection criteria can be used.
- Specify the name of a data set to contain the extract object.
- Specify the following execution options:
Press Enter to process.If you specified Y for Update Extended Options, the Extract Options panel displays for the selected extraction method. Specify the advanced and extract options.If you specified batch as your process mode, the Batch JCL Specification panel appears. Specify the options for running the batch job and submit. The Batch Processor In-Progress panel appears. The Online Progress Report displays the steps that were taken during the extraction. The Audit Message File appears next. This file contains extract processing information and a summary report. After you have successfully performed an extract, proceed with identifying the target.
- Process Mode (batch or online)Specify whether to perform the extract in batch mode or online mode.If you are controlling the storage of keys for extracted rows or preventing a row from writing to an extract object multiple times,do notspecify the process mode until after you select these extraction options (see Update Extended Options below).
- Extract MethodSpecify whether to unload the source objects using SQL statements (S) or a utility (U). To view or update the options for these extraction methods, specify Y for Update Extended Options.
- Update Extended OptionsSpecify Y to view or update the extraction options for the SQL or utility extraction methods.For more information about these options, see How to Specify SQL Extraction Options and How to Specify CA Fast Unload Extraction Options).
- Update AllocationsSpecify whether to update the default extract object allocations and sort options. The default is N.The default options work for most extractions, from a handful of rows to millions of rows. x37 abends are dynamically intercepted and handled. You do not need to struggle with constantly adjusting allocation parameters to allocate sufficient space for the extract data set to prevent x37 abends. An x37 abend occurs when the extraction is stopped because the data set that was allocated for the extract object is full.Writing the extract object to a disk or tape data set is supported. However, disk is recommended for best performance.The sort options let you control the dynamic allocation of the sort data sets that are used to perform the sort. You can specify the device type and the number of data sets to be used.
- Intercept ErrorsSpecify whether to intercept errors that occur during an extraction. If an error occurs, you can restart the extraction from the point of failure.
- Extract DDLSpecify whether to auto-create the target objects using information that was gathered from the catalog (Extract DDL).
- Overwrite EXTOBJ.Specify whether to overwrite the extract object (EXTOBJ) for each execution.
- Set Extract ParametersSpecify whether to set extract parameters that you can externalize and modify as needed. For example, if SQL is the extract method, you can modify the total limit of rows to be extracted from an object to ensure that a complete set of RI data is retrieved. You can also modify the WHERE clause and select an alternative WHERE clause for use in batch.