Textual Data Definition Format
The Textual Data Definition (TDD) standard allows you to create an SXV4 database based on data stored in text files, as opposed to connecting to a relational database. This can be useful in situations where data is not available in a database and so is extracted to text files instead. It can also be slightly faster to channel from text-based sources, as this method avoids the performance overhead of connecting to an RDBMS.
This section describes the TDD format. You can use this information to convert your data into the TDD format for processing with SuperCHANNEL.
Files Required for a TDD
The TDD format is actually a directory of text files containing all the required information to define the database structure as well as the data itself. There are three types of file that contribute to a TDD:
| Control files | Define the layout of information in the data files. These files are required for a TDD to be valid. If you are creating your own TDD that you will need to create these files yourself in a text editor, although there are a number of samples provided with SuperCHANNEL and via this documentation site that you can use as a basis for creating your own. Learn more about the control files. |
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| Registry tables | (Optional) Perform the same function as registry tables in a relational database; the registry tables can be used to give SuperCHANNEL information about the design of the target database, such as which tables are fact tables, and which are classifications. Registry tables are optional and are not required in order to make a valid TDD, although creating registry tables can save you time using the SuperCHANNEL GUI, especially if you can generate them programmatically from your data source. |
| Data files | Contain the actual data (i.e. the contents of the fact and classification tables). The structure of the data files is defined in the control files, but typically these will be comma separated, tab delimited or fixed width format files containing the table data, and saved as CSV (Comma Separated Values) files or TXT (text) files. |
Examples
There are some example TDD format files supplied with SuperCHANNEL. If you installed to the default location then the examples are located in C:\ProgramData\STR\SuperCHANNEL\examples.
| Household | A sample of some survey data.
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| People | A sample database containing information about individuals.
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Connecting to a TDD Source
Once you have converted your source data to the TDD format described here, you can use the supplied sctextdriver to connect to the TDD source. See Connecting to TDD Data Sources for more information.