The Subsetting is performed using automated VIP workflows. Each high-speed workflow performs "Actions". The actions and workflows are executed using the VIP Server Controller. Each Action is informed either by sheets in the Basic/Advanced Control Spreadsheet, or by information read from the Source Database. Some of this information can be user defined; other information is generated by the Subset actions.
The actions to run the Basic Subset are:
The GETMETADATA Action retrieves the metadata from the Source Data that is needed to run the Subset. It is a composite action, made up of three actions. Each action be run in a single action as "GETMETADATA", or can be run separately. GETMETADATA is recommended for simplicity and speed. Running the actions individually is valuable for closer analysis, learning, and debugging.
The PREPENV Action create tables and indexes in the Staging Database.
The BUILDMODEL creates the rules to drive the Subset.
The SUBSET Action writes data to the Staging Database.
A Subset will run until one of the following completion criteria is fulfilled:
A maximum specified number of rows is reached;
A maximum number of recursions is reached;
The "Found Criteria" are fulfilled;
There are no more rows in the Source Database that match the Subset criteria. The Subset will stop recurring when no rows were added in the last recursion.
This Basic Subset will generate the Advanced Control Spreadsheet, containing additional sheets. These sheets contain additional parameters and the automatically formulated Subset rules. The information in these sheets can then be used to perform Advanced Subsets. You can subset iteratively by toggling the Subset Rules, Tables and Relationships that will be used in the next Subset.
Actions used to perform iterative Subsets after the Basic Subset include:
DROP: Drops the tables registered by the TABLES action. You will only run this if something has gone wrong in a Subset, and you want to create a wholly new Data Subset.
PREPENV: If you drop the tables, you will need to re-register tables before performing the next Subset.
TRUNCATE: Deletes data from the Target Database or Schema.
BUILDMODEL: Creates the rules to drive the Advanced Subset, based on the Control Spreadsheet.
SUBSET: Writes the new Data Subset to the Staging Database, based on the updated Control Spreadsheet.