Overview of the Extract Step

The Extract Process selects data from a source (one or more tables in a database) and copies that data to a destination (an Extract File). To extract data, you must create an Extract Request that includes the specifications for the data to be extracted, called the Access Definition, and the parameters for the Extract Process.

You can process the Extract Request immediately, or schedule the process to run automatically. You can also run the Extract Process from the command line, using overrides for specifications in the request.

Extract Request

The Extract Request Editor allows you to select parameters for processing the Extract Request. These parameters include:

  • The Extract File, Access Definition, row limit, and items to extract: data, objects (metadata), or both.
  • Types of objects to extract: primary keys, relationships, indexes, aliases/synonyms, functions, defaults, UDTs, packages, procedures, sequences, triggers, views, and/or rules. (Move always extracts table and column definitions.)

You can choose to run the Extract Request immediately or schedule the request for later processing.

Extract File

The Extract File contains the selected relationally intact data, the object definitions, or both. The Extract File is stored locally on the client system or on a shared file server. After you create an Extract File, you can use the file as often as needed to create new or refresh existing databases.

After you have extracted data and created an Extract File, you can browse the contents of the file. This is useful to ensure that the contents are as expected.

Access Definition

The Access Definition governs the overall Extract Process. An Access Definition specifies the tables, relationship traversal, and selection criteria for the data you want to extract. You can select a named Access Definition or create a new Access Definition for a single Extract Request. The Access Definition enables you to:

  • Specify the set of tables to be included in the Extract Process. You can specify the name of a single table and request that Move provide the names of all related tables. One table is identified as the Start Table, or table from which data is first extracted.
  • Select relationships to be traversed to extract the data. Move has default rules for how relationships are traversed between the specified tables. You can select from a list of all of the relationships defined to the database and to the Optim™ Directory. (The relationships contained in the Optim Directory supplement the relationships contained in the database.)
  • Define criteria for the rows to be extracted by specifying:
    • Selection criteria for any selected table using SQL syntax.
    • A selection of rows chosen while browsing the data (Point and Shoot).
    • A sampling of rows, accomplished by extracting every nth row.
    • A maximum number of rows for a single table.
    • A maximum number of children per parent.
    • Grouping (for example, extract 20 customers from each of the 50 states).
  • Ensure that the desired data is extracted using the Show Steps function to review how Move will traverse the database.

Extract Process Report

An Extract Process Report is generated as part of the Extract Process. The report contains general information and statistics about the process. The content of the report reflects what has been extracted─data, object definitions, or both.