Output Selector: Earliest Value

1.3.3.10.3 Output Selector: Earliest Value

The Earliest Value output selector evaluates a date stamp on each record to select a value to use for another attribute.

Use the Earliest Value output selector where records have date stamps, and the best value for an attribute is likely to come from the record with the earliest stamp.

For example, in some cases, data is carefully checked and cleaned on migration to a new system, but duplicate entries are created with errors. In this case, the earlier records may be better. The date stamp column must be selected as an input to the output selector, in addition to the attribute for which you want to determine a merged value.

The following table describes the configuration options:

Configuration Description

Configuration	Description
Inputs	For the actual output value, any input attributes of any type from any input data sets may be configured. A Date attribute must be configured in order to establish which record should be considered the 'Earliest'.
Options	Specify the following options: `Use first non-empty value if tied?`: this option provides a way of selecting a value arbitrarily if more than one record exists with the same, earliest, Date/time stamp. The first alphabetically sorted value will be selected for String values, the lowest value for Numbers, and the earliest value for Dates. Type: Yes/No. Default value: Yes.

Inputs

For the actual output value, any input attributes of any type from any input data sets may be configured.

A Date attribute must be configured in order to establish which record should be considered the 'Earliest'.

Options

Specify the following options:

Use first non-empty value if tied?: this option provides a way of selecting a value arbitrarily if more than one record exists with the same, earliest, Date/time stamp.

The first alphabetically sorted value will be selected for String values, the lowest value for Numbers, and the earliest value for Dates.

Type: Yes/No. Default value: Yes.

Example

In this example, the Earliest Value output selector is used to select the Earliest Value for a Company Name field, based on the date stamps of the records.

Example configuration

Use first non-empty value if tied? = No

Example output

The following table shows example output using the Earliest Value selector:

Table 1-102 Example Output Using Earliest Value Selector

Input A (CompanyName, Date)	Input B (CompanyName, Date)	Output value (Earliest Value)
Barclays Bank plc, 10/01/1998	Barclays Bank (Bristol) PLC, 14/05/2002	Barclays Bank plc
PriceWaterhouse Coopers, 10/01/1998	PWC, 24/03/2000	PriceWaterhouse Coopers
Oracle Limited, 24/03/2003	Oracle, 24/03/2003	Selection error (needs manual resolution)
Oracle, null	Oracle, 24/01/1997	Oracle