Data loading formats
In the database environment, there is always the need to load data from external sources such as files, pipes, or sockets into a table. These external sources have various formats to represent each of the data types individually and together as records or rows.
When
you load data from applications such as an RDBMS, a web server, or some other structured data store,
they might export data into files or streams in different formats. The following formats are used:
- Text-delimited
- The format that is commonly used for data loading is the text-delimited format. In this format, every value of a field or column ends with a delimiter, and each set of these values in rows or records, even the last row or record, has an end-of-record delimiter, typically a newline character.
- Fixed-length
- The fixed-length loading format allows for a more expressive form of external table definition, thus increasing the kinds of data formats and layouts that you can load. Each row or record, even the last row or record, has an end-of-record delimiter, typically a newline character.
- Compressed binary
- This format compresses the data before a backup or restore to benefit performance. Also called internal format, it typically yields smaller data files, retains information about the Netezza Performance Server topology, and thus is often faster for backing up and restoring data. The internal format is not a documented interface and might change between releases. For more information about backing up and restoring, see the IBM® Netezza® System Administrator’s Guide.