The HPL data-load process
The data-load process reads a source data file, converts the data to a different format, and inserts the converted data into a database table.
The source data can come from one or more of the following sources:
- Files
- Tapes
- Pipes (application-generated data) (UNIX™)
The supports load and unload data greater than 2 GB to files and tapes.
During conversion, the source data is often manipulated so that
the converted data displays different characteristics. Examples of
this manipulation include:
- Changing lowercase letters to uppercase letters
- Loading default values, loading certain table columns, or replacing nulls
- Masking the data to include only part of a value
- Converting from one data type to another, such as conversion of a numeric string to a float
- Converting from the code set of one locale to the code set of another locale
When you prepare to run a data load with the HPL, you describe
the actions that the HPL must take by defining a set of metadata components.
The components describe different aspects of the load process. The
HPL uses information from:
- The device array to find the set of the source-data files
- The format to define the data types and layout of the source data
- The filter to select the records from the source data that should be written to the database table
- The map to modify and reorganize the data
The ipload utility helps you prepare the components. Load data to a database table, addresses the process of loading a file to a database.
The following figure shows the data load process. The figure summarizes
the data-load process by showing how data moves from data files to
table entries.