Use the attributes properties tab to specify the characteristics of the data in a table column. You can open attribute properties from:
- the repository. Attributes are listed under their streamtable
- the Stream the Table properties → Attributes table
- other attribute lists.
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| Name | Enter the name of the attribute.
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| Type | Select the attribute type for the data.
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Length | This field is available when Type is String. By default strings are 50 characters long. Optionally specify a different string length of between 1 and 4000. For strings longer than 4000 characters, set a Type of Bigstring. | |||||||||||||||||
| Precision | This field is available when Type is Integer. Enter the maximum number of digits allowed in whole numbers. By default, integers are 10 digits long. Optionally specify a different integer precision of between 1 digit and 38 digits. | |||||||||||||||||
| Significant Figures | This field is available when Type is Decimal. Enter the maximum number of total digits for decimal numbers. By default decimals have 10 significant figures. |
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| Decimal Places | This field is available when Type is Decimal. Enter the maximum number of digits allowed after the decimal point. By default, decimals have 2 decimal places. This must be less than the number of significant figures. | |||||||||||||||||
| Local |
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| Order | The order of the attributes in the streamtable. Stream Table attribute expressions are evaluated in this order. This is important when you need to use the results of a calculation in another attribute:
In the attribute list, the attribute that calculates the result must come before the attribute that requires the result. | |||||||||||||||||
| Expression | The expression used to generate the attribute value. This is written as a PhixFlow Expression. It must evaluate to a single value, of the type specified in the Type field. | |||||||||||||||||
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| Indexed |
To improve performance, index an attribute when the stream table has a large data set and an output pipe from the stream table uses this attribute to:
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| Filter conditions are case-independent by default |
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| Key |
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Translate Values
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| Cache Key | Enter an expression to be evaluated for each stream table item (data record) in the streamtable. The expression can:
Once calculated, the cache key value persists throughout subsequent stream table calculation, rather than being created from scratch for each stream table item as normal. This allows you to keep track of the calculation as it progresses. This means you can use a "persistent" attribute value in other expressions. |
Access Permissions
For details about how to control access to a stream an attribute, see Common Properties → Access Permissions.
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All stream attributes have a data type. When loading data from a source, such as a file or database, PhixFlow applies the data type from the source. If there is no data type specified, PhixFlow applies the default type of string.
You can change the type of a stream an attribute before the data has been loaded into the streamtable.
Once the stream table contains datarecords, you may be able to change the attribute's data type, depending on the database on which PhixFlow runs. PhixFlow reports an error if you are not permitted to change the data type. In this case you can rollback all stream record-sets so that the stream table no longer contains datarecords; see Rollback.
String
Apply a string type to sequences of characters, such as letters, numerals, symbols and punctuation marks. By default string attribute types have a default length of 50. Specify a different string length in Basic Settings → Length.
Anchor Bigstring Bigstring
Bigstring
| Bigstring | |
| Bigstring |
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The PhixFlow administrator can configure the length of a bigstring using System Configuration → System Tuning → Maximum Bigstring Size.
Integer
Apply an integer type to whole numbers (not a fractions or decimals) that can be positive, negative, or zero. By default integers have a precision of 10 digits. Specify a different integer length in the Basic Settings → Precision.
If you store a number with decimal places as an integer it will be truncated.
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