Algorithm: Date Shift (KBA7105)

Applicable Delphix Versions

Click here to view the versions of the Delphix engine to which this article applies

Major Release	All Sub Releases
6.0	6.0.7.0, 6.0.8.0, 6.0.8.1, 6.0.9.0, 6.0.10.0, 6.0.10.1

At a Glance

Versions:

Applicable Delphix Masking versions: From 6.0.7.0.

Released:

This algorithm was released in version 6.0.7.0 and will replace the old Date Shift algorithms (KBA1812). It has been created using the Date and Plugin Framework.

Characteristics:

Date Shift	Framework	UL¹	RI²	1:1³	NSV⁴
Discrete	Plugin	n/a	Yes	No	No
Fixed	Date	n/a	Yes	Yes	Yes
Variable	Plugin	n/a	No	No	Yes

¹ Unique values in Lookup - Not applicable.
² Referential Integrity - The masked value will be the same between tables, databases, and jobs.
³ 1:1 Mapping - Special MC case. The masked value will be mapped uniquely to the input value.
⁴ Never mask to Same Value - Two of the DateShift algorithms are designed so that the masked value will never be the same as the Input value.

Framework:

Frameworks used:

Date.
Plugin (Algorithm SDK).

Data Type:

These are the valid Data Types:

Date, Datetime, Int, Char, VarChar, nChar, nVarChar (and similar).

Encoding:

ASCII Numeric

Strength:

Very fast

Customization:

None

Details about the algorithms

These algorithms come pre-configured with the masking engine and the algorithms cannot be modified.

Memory Requirements

These algorithms have a very small memory footprint.

Masked Value

The algorithm masks only the Day part of the date (including dates with time). The year, month, hour, min, etc are left as is.

Date Formats

A date format must be specified. This field appears when you select the DATE SHIFT algorithm from the Masking Algorithm dropdown list.

The default format is 'yyyy-MM-dd' and the list contains some common formats. You can also type the date format desired if the date format is not listed.

Special characters and invalid date strings

Special characters and invalid date strings will be passed through unmasked. NULL and blank string will be passed through unmasked and all other cases will be marked as Nonconforming Data (and passed through).

Casting to string

It might be needed to CAST a date stored in a Data Type that is not supported to a STRING. Look at the value and CAST as required and set Date Formats accordingly.

For example, if a date is stored in an unsupported data type and the SELECT returns 20210626, then cast the value to a STRING and set the Date Format to YYYYMMDD.

Examples

Masking Examples

Below are examples of the three algorithms: Discrete, Fixed, and Variable.

ID reference number.
Orig - The Original date.
DS_Discrete - The masked value using Discrete.
DS_Fixed- The masked value using Fixed.
DS_Variable - The masked value using Variable.

With date only (format: 'yyyy-MM-dd')
+----+------------+-------------+------------+-------------+
| id | orig       | DS_Discrete | DS_Fixed   | DS_Variable |
+----+------------+-------------+------------+-------------+
| 1  | NULL       | NULL        | NULL       | NULL        | << Passthrough values
| 2  |            |             |            |             |
+----+------------+-------------+------------+-------------+
| 3  | 1977-02-01 | 1977-02-06  | 1977-02-06 | 1977-02-03  | << Note: id 3 same as 4
| 4  | 1977-02-01 | 1977-02-06  | 1977-02-06 | 1977-02-10  |    Variable has different value.
+----+------------+-------------+------------+-------------+
| 3  | 1977-02-01 | 1977-02-06  | 1977-02-06 | 1977-02-10  | << Different year
| 5  | 1978-02-01 | 1978-02-20  | 1978-02-06 | 1978-02-04  |
+----+------------+-------------+------------+-------------+
| 3  | 1977-02-01 | 1977-02-06  | 1977-02-06 | 1977-02-10  | << Different month
| 6  | 1977-03-01 | 1977-03-13  | 1977-03-06 | 1977-03-06  |
+----+------------+-------------+------------+-------------+
| 3  | 1977-02-01 | 1977-02-06  | 1977-02-06 | 1977-02-10  | << Different day
| 7  | 1977-02-02 | 1977-02-06  | 1977-02-07 | 1977-02-12  |
+----+------------+-------------+------------+-------------+
| 8  | 1978-04-25 | 1978-04-06  | 1978-04-30 | 1978-04-01  | << Month rollover
| 9  | 1978-04-26 | 1978-04-06  | 1978-04-01 | 1978-04-28  |
| 10 | 1978-04-27 | 1978-04-06  | 1978-04-02 | 1978-04-01  |
| 11 | 1978-04-28 | 1978-04-06  | 1978-04-03 | 1978-04-29  |
| 12 | 1978-04-29 | 1978-04-06  | 1978-04-04 | 1978-04-07  |
| 13 | 1978-04-30 | 1978-04-06  | 1978-04-05 | 1978-04-07  |
| 14 | 1978-05-01 | 1978-05-24  | 1978-05-06 | 1978-05-03  |
| 15 | 1978-05-02 | 1978-05-24  | 1978-05-07 | 1978-05-06  |
+----+------------+-------------+------------+-------------+
Note: DateShift Fixed and Variable will never mask to the same as the input.


With time: (format: 'yyyy-MM-dd HH:mm')
+----+------------------+------------------+------------------+------------------+
| ID |       Orig       |    DS_Discrete   |      DS_Fixed    |   DS_Variable    |
+----+------------------+------------------+------------------+------------------+
| 1  | 1978-04-30 14:34 | 1978-04-06 14:34 | 1978-04-05 14:34 | 1978-04-08 14:34 |
+----+------------------+------------------+------------------+------------------+

Nonconforming Data Examples

Below are some examples of Nonconforming Data when masking a date.

Date format set to 'yyyy-MM-dd'.

+----+------------------+------------------+-----------------------+
| id | orig             | Nonconforming    | Comment               |
+----+------------------+------------------+-----------------------+
| 16 | 1978-04-02 14:34 | NNNNPNNPNNZNNPNN | Incorrect Date format |
| 17 | 1978-31-31       | NNNNPNNPNN       | Invalid date          |
| 18 | FOO BAR          | LLLZLLL          | Not a date            |
+----+------------------+------------------+-----------------------+

KBA