Improvements to the Type System

Contents:

This section provides information on improvements to the Trifacta® type system.

Release 7.1.1

PII - Improved matching for social security numbers

In prior releases, Personally Identifiable Information (PII) for social security numbers was identified based only on the length of values, which matched too broadly.

In this release, the constraints on matching of SSN values has been tightened when applied to PII. 

For more information, see Social Security Number Data Type.

For more information, see Data Type Validation Patterns.

PII - Improved and expanded matching for credit card numbers

In prior releases, PII for credit card numbers was identified base on 16-digit values. 

In this release, the matching constraints have been expanded to include 14-digit credit card values. 

Also, the constraints around valid 16-digit numbers have been improved with better recognition around values for different types of credit cards. In the following table, you can see lists of valid test numbers for different credit card types and can see how detection of these values has changed between releases.

For more information, see Credit Card Data Type.

For more information, see Data Type Validation Patterns.

Release 6.0 and earlier

Mismatched data types

Where there are mismatches between inputs and the expected input data type, the following values are generated for the mismatches:

Three-value logic for null values

The Trifacta Photon running environment has been augmented to use three-value logic for null values.

When values are compared, the result can be true or false in most cases.

If a null value was compared to a null value in the Trifacta Photon running environment:

• In Release 3.0 and earlier, this evaluated to true.
• In Release 3.1 and later, this evaluates to an unknown (null) value.

This change aligns the behavior of the running environment with that of SQL and Hadoop Pig.

Improved handling of null values

Assume that the column nuller contains null values and that you have the following transform:

derive value:(nuller >= 0)

Prior to Release 3.1, the above transform generated a column of true values.

In Release 3.1 and later, the transform generates a column of null values.

More consistent evaluation of null values in ternaries

In the following example, a_null_expression always evaluates to a null value.

derive value: (a_null_expression ? 'a' : 'b')

In Release 3.0, this expression generated b for all inputs on the Trifacta Photon running environment and a null value on Hadoop Pig.

In Release 3.1 and later, this expression generates a null value for all inputs on both running environments.

For example, you have the following dataset:

You test each row for the presence of the string can't:

derive value: if(find(MyStringCol, 'can\'t',true,0) > -1, true, false) as:'MyFindResults'

The above transform results in the following:

In this case, the value of false is not written to the other columns, since the find function returns a null value. This null value, in turn, nullifies the entire expression, resulting in a null value written in the new column.

You can use the following to locate the null values:

derive value:isnull(MyFindResults) as:'nullInMyFindResults'

Datetime changes

Raw date and time values must be properly formatted

Before this release, you could create a transform like the following:

derive value:date(2016,2,15)

This transform generated a column of map values, like the following:

{"year":"2016","month":"2","date":"15"}

Beginning this release, the above command is invalid, as the date values must be properly formatted prior to display. The following works:

derive value:dateformat(date(2016,2,15),'yyyy-MM-dd')

This transform generates a column of Datetime values in the following format:

2016-02-15

Time:

Before this release:

derive value:time(11,34,58)

Prior release output:

{"hours":"11","minutes":"34","seconds":"58"}

This release:

derive value:dateformat(time(11,34,58), 'HH-mm-ss')

This release's output:

11-34-58

• See DATEFORMAT Function.
• See UNIXTIMEFORMAT Function.

Date formatting functions supports 12-hour time only if AM/PM indicator is included

Beginning in this release, the unixtimeformat and dateformat functions requires an AM/PM indicator (a) if the date formatting string uses a 12-hour time indicator (h or hh).

Valid for earlier releases:

derive value: unixtimeformat(myDate, 'yyyy-MM-dd hh:mm:ss') as:'myUnixDate'

Valid for this release and later:

derive value: unixtimeformat(myDate, 'yyyy-MM-dd hh:mm:ss a') as:'myUnixDate'

These references in recipes fail to validate in this release or later and must be fixed.

• See DATEFORMAT Function.
• See Unixtimeformat Function.

Un-inferrable formats from dateformat and unixtimeformat functions are written as strings

If a formatting string is not a datetime format recognized by the Trifacta platform, the output is generated as a string value.

This change was made to provide clarity to some ambiguous conditions.

Colon as a delimiter for date values is no longer supported

Beginning in this release, the colon (:) is no longer supported as a delimiter for date values. It is still supported for time values.

When data such as the above is imported, it may not be initially recognized by the Trifacta application as Datetime type.

To fix, you might apply the following transform:

replace col:myDateValue with:'-' on:`-` global:true

The new column values are more likely to be inferred as Datetime values. If not, you can choose the appropriate Datetime format from the data type drop-down for the column. See Data Grid Panel.