Overview
Use the stream attributes properties tab to specify the characteristics of the the data in a table column. You can open attribute properties from:
...
| Field | Description | |||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Name | Enter the name of the attribute. | |||||||||||||||||
| Type | Select the attribute type for the data.
| |||||||||||||||||
Length | This field is available when Type is String. Enter the maximum number of characters allowed in text data. For unlimited text strings. 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. 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. |
| ||||||||||||||||
| 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 |
| |||||||||||||||||
| Order | The order of the attributes in the stream. Stream 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. | |||||||||||||||||
...
| Field | Description | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Indexed |
To improve performance, index an attribute when the stream has a large data set and an output pipe from the stream uses this attribute to:
| ||||||||||
| Filter conditions are case-independent by default |
| ||||||||||
| Key |
| ||||||||||
| Cache Key | Enter an expression to be evaluated for each stream item (data record) in the stream. The expression can:
Once calculated, the cache key value persists throughout subsequent stream calculation, rather than being created from scratch for each stream 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. |
...
| Anchor | ||||
|---|---|---|---|---|
|
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 attribute before the data has been loaded into the stream.
Once the stream contains data, you may be able to change the 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 sets so that the stream no longer contains data; 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. However you can configure a minimum length of 1 and a maximum length of 4000Specify a different string length in Basic Settings → Length.
Anchor Bigstring Bigstring
Bigstring
| Bigstring | |
| Bigstring |
Apply a bigstring type to text strings over 4000 characters long. Bigstring is a different data type to string. For PhixFlow instances that use an Oracle database, bigstrings:
- cannot be sorted or aggregated
- can only be filtered with the conditions:
(not) containsis (not) null(not) starts with(not) ends with.
The maximum bigstring size can be configured in 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. The number of digits in an integer indicates its precision.
- The default precision is 10 digits
- The minimum precision is 1 digit
- The maximum precision is 38
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.
...
| Note |
|---|
Ensure your decimal type has the number of decimal places you need for your data. Once the data is loaded into PhixFlow, you will not be able to recover excess decimal places. |
The PhixFlow administrator can configure the default number of decimal places is set in System Configuration → General Settings → Decimal places.
...