Task B: Define Parameters

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Chapter 3 Defining TDS, EES, SES, and TEM Tables : Task B: Define Parameters

Task B: Define Parameters

Purpose of this Task

In this optional task you specify parameters. There are two types of parameters you can specify using the parameter segment of the screen:

•

Data

•

Location

Parameter Segment

The following example illustrates the fields used to define the data (REGION) and location (LOCATION) parameters. To view additional fields, press PF11.

Parameter Name Typ Syn Len Dec Class

---------------- - -- --- -- -

- REGION I C 16 0 D

- LOCATION I C 16 0 L

Considerations for Defining Parameters

Use the following table to determine if you should define parameters and the type of parameters to define if they are required.

Considerations

Parameterize

Type of Parameter

The data is single dimensional. It does not partition easily or there is no need to partition the data.

N

The data has more than one dimension. It logically breaks down into one or more partitions (called instances). These instances can then be used to access the data.

Y

Data

The same type of data is used in more than one location and can be stored in different TIBCO Object Service Broker databases.

Y

Location

Data Parameters

Data parameters are used to partition data. They can be defined for TDS, Execution Environment ((EES), temporary (TEM), and session (SES) tables.

Defining Data Parameters

A maximum of four data parameters can be specified for a table, to a total maximum length of 240 bytes. The following fields are used to define data parameters. You can enter the information into the fields in any order. For valid values, press PF1.

Parameter Name

Enter the name of the data parameter. The order in which the names are entered determines the order in which supplied values are processed. Data parameters are relocated to the top of the parameter list when the table definition is saved.

Typ

Enter the semantic data type of the parameter. Refer to TIBCO Object Service Broker Programming in Rules for more information and a list of valid values.

Syn

Enter the syntax of the parameter. Refer to TIBCO Object Service Broker Programming in Rules for more information and a list of valid values.

Len

Specify the length of the parameter value. The value is in bytes and valid values are determined by the syntax of the parameter. For valid lengths, refer to TIBCO Object Service Broker Programming in Rules. Each data parameter must have a non-null value.

Dec

Specify the number of digits to the right of the decimal point. In most cases this is optional. It is relevant only for syntax P.

Class

Specify D to indicate that the parameter is a data parameter.

Reference

[Optional] Specify the name of a reference table. Specify a value only if a table is to be referenced when a user is inserting or replacing a value in the parameter. You then ensure that the user enters valid values for the data parameter. The reference table must be non-parameterized. If the new value does not exist as a primary key value in the referenced table, the action fails validation.

What is a Location Parameter?

A location parameter is used to identify the location (MetaStor) where the data in a table is stored. It cannot be defined for SES tables. The name of a location parameter is provided by default when a new table is being defined. Use the D line command to delete the parameter if it is not required. The location parameter is moved to the bottom of the parameter list when the table definition is saved.

When you access a table via a rule, which passes a location parameter, the value for the location parameter must not be NULL or blank.

Defining a Location Parameter

The following fields are used to define the location parameter. You can enter the information into the fields in any order. For valid values, press PF1.

Parameter Name

Change the name of the location parameter, if required. The value of LOCATION is provided by default but it can be modified or deleted. The name of the location parameter must be the last parameter name listed.

Typ

Type I for the semantic data type.

Syn

Type C for the syntax of the parameter.

Len

Type 16 for the length.

Class

Type L to indicate that the parameter is a location parameter. Only one location parameter can be specified.

Reference

Specify the name of a reference table (this is optional). Specify a value only if a table is to be referenced when a user is inserting or replacing a value in the table instance. You then ensure that the user enters valid values for the location parameter. The reference table must be non-parameterized. If the new value does not exist as a primary key value in the referenced table, the action fails validation.

The value in the reference field is ignored for a minimal table definition. Refer to Defining a Minimal Definition.

Default

Specify the name for the default node to be used on data access (this is optional). Even if a value is provided, when an access is made to the data, the location is determined using the order of evaluation described in Order of Evaluation to Determine Location.

Src

Indicate how the name of the node is to be determined (this is optional). The value for the node name can be derived from a functional rule named in the Sourcename field or provided through the users’ session options. Even if a value is provided, when an access is made to the data, the location is determined using the order of evaluation described in Order of Evaluation to Determine Location.

Sourcename

Identify the name of the source rule. This is used only if the Src field is set to D. The rule named must be a functional rule that returns the value for the node name. It must have an argument for the table name and arguments for each of the data and location parameters. For more information about coding considerations, refer to Chapter 7, Coding Considerations for Event, Location, and Derived Value Rules.

Considerations	Parameterize	Type of Parameter
The data is single dimensional. It does not partition easily or there is no need to partition the data.	N
The data has more than one dimension. It logically breaks down into one or more partitions (called instances). These instances can then be used to access the data.	Y	Data
The same type of data is used in more than one location and can be stored in different TIBCO Object Service Broker databases.	Y	Location

Parameter Name	Enter the name of the data parameter. The order in which the names are entered determines the order in which supplied values are processed. Data parameters are relocated to the top of the parameter list when the table definition is saved.
Typ	Enter the semantic data type of the parameter. Refer to TIBCO Object Service Broker Programming in Rules for more information and a list of valid values.
Syn	Enter the syntax of the parameter. Refer to TIBCO Object Service Broker Programming in Rules for more information and a list of valid values.
Len	Specify the length of the parameter value. The value is in bytes and valid values are determined by the syntax of the parameter. For valid lengths, refer to TIBCO Object Service Broker Programming in Rules. Each data parameter must have a non-null value.
Dec	Specify the number of digits to the right of the decimal point. In most cases this is optional. It is relevant only for syntax P.
Class	Specify D to indicate that the parameter is a data parameter.
Reference	[Optional] Specify the name of a reference table. Specify a value only if a table is to be referenced when a user is inserting or replacing a value in the parameter. You then ensure that the user enters valid values for the data parameter. The reference table must be non-parameterized. If the new value does not exist as a primary key value in the referenced table, the action fails validation.

Parameter Name	Change the name of the location parameter, if required. The value of LOCATION is provided by default but it can be modified or deleted. The name of the location parameter must be the last parameter name listed.
Typ	Type I for the semantic data type.
Syn	Type C for the syntax of the parameter.
Len	Type 16 for the length.
Class	Type L to indicate that the parameter is a location parameter. Only one location parameter can be specified.
Reference	Specify the name of a reference table (this is optional). Specify a value only if a table is to be referenced when a user is inserting or replacing a value in the table instance. You then ensure that the user enters valid values for the location parameter. The reference table must be non-parameterized. If the new value does not exist as a primary key value in the referenced table, the action fails validation. The value in the reference field is ignored for a minimal table definition. Refer to Defining a Minimal Definition.
Default	Specify the name for the default node to be used on data access (this is optional). Even if a value is provided, when an access is made to the data, the location is determined using the order of evaluation described in Order of Evaluation to Determine Location.
Src	Indicate how the name of the node is to be determined (this is optional). The value for the node name can be derived from a functional rule named in the Sourcename field or provided through the users’ session options. Even if a value is provided, when an access is made to the data, the location is determined using the order of evaluation described in Order of Evaluation to Determine Location.
Sourcename	Identify the name of the source rule. This is used only if the Src field is set to D. The rule named must be a functional rule that returns the value for the node name. It must have an argument for the table name and arguments for each of the data and location parameters. For more information about coding considerations, refer to Chapter 7, Coding Considerations for Event, Location, and Derived Value Rules.