Using the Parameter File to Customize Stream Execution

When a stream is published, the image file contains information about the data source and output data destination that were selected in the original stream. However, it is often convenient to run a stream against data from a different data source or to reroute the output data to a different destination. This can be done by editing the stream's parameter file.

This is particularly important when you will be executing the published stream on a computer different from the one on which it was created. You will need to update the locations of the input and output files to reflect the structure of the target computer. Note that published streams do not support relative paths, making it especially important to verify the data locations in your parameter file. (If you specify relative paths in the Export node options when publishing the stream, IBM® SPSS® Modeler will convert them to absolute paths before creating the image and parameter files for the published stream.)

You can also use the parameter file to set execution options and to change the values of stream parameters.

Parameter values are specified in the parameter file as <name.attribute>=<value> pairs. For some parameters, the parameter name contains an ID digit to distinguish nodes of the same type in the stream. For example, in a stream where both input and output refer to a database connection, the parameters describing the input connection might be dbconn0.datasource, dbconn0.user, etc., and the parameters associated with the output connection might be dbconn1.datasource, dbconn1.user, etc. Values are always enclosed in double quotes. The parameter file contains the following parameters, all of which can be changed to customize stream execution.

Table 1. Execution parameters
Parameter	Purpose
`dbconn`x`.datasource`	Data source name (DSN).
`dbconn`x`.user`	User name for restricted access databases.
`dbconn`x`.password`	Password for restricted access databases.
`dbconn`x`.epassword`	Encoded password for restricted access databases. To generate an encoded password, select Encode Password from the Tools menu of the IBM SPSS Modeler user interface. Copy and paste the encoded password as needed.
`dbconn`x`.password_required`	Flag indicating whether to prompt for a password for this database connection. (The value is "Y" or "N".) Automatically set to "N" when there is no password specified at publish time.
`dbconn`x`.catalog`	Catalog associated with the database connection.
`dbtable`x`.name`	Base table name. Note: The order of fields in a new table must be the same as the order of fields in the originally published stream.
`dbtable`x`.schema`	Schema name.
`dbtable`x`.catalog`	Catalog associated with the current table.
`file`x`.name`	Filename for data file. Note: The order of fields in a new input file must be the same as the order of fields in the originally published stream.
`file`x`.path`	File location (directory name).
`file`x`.field_names_included`	For text format files, the flag indicating whether the field names are included as the first line of the file. (The value is "Y" or "N".)
`file`x`.field_separator`	For text format files, the character(s) used to separate field values.
`file`x`.decimal_separator`	For text format files, the character used for the decimal point.
`options.angle_in_radians`	Flag indicating whether radians are used as the unit of measurement in trigonometric CLEM expressions. (The value is "Y" or "N".)
`options.date_2digit_baseline`	Defines the century for dates specified with two-digit years.
`options.date_baseline`	The baseline year (always January 1) used by CLEM date functions that work with a single date.
`options.time_rollover`	Flag indicating whether negative time differences refer to the past.
`options.decimal_separator`	The default decimal point character in text files.
`options.time_format`	Time format used when strings are interpreted as times by CLEM time functions.
`options.date_format`	Date format used when strings are interpreted as dates by CLEM date functions.
`options.timestamp_format`	Format used when reading timestamp fields as strings from ODBC data sources.
`param`x`.value`	Stream parameter value. Note: The parameter name, description, and storage type are included for reference but cannot be changed. The value must be valid for the type.