Matching Records from One Source to Another Source

This procedure describes how to use an Interflow Match stage to identify records in one source that match records in another source. The first source contains suspect records and the second source contains candidate records. The dataflow only matches records from one source to records in another source. It does not attempt to match records from within the same source. The dataflow groups records into collections of matching records and writes these collections to an output file.

In Enterprise Designer, create a new dataflow.
Drag two source stages onto the canvas. Configure one of them to point to the source of the suspect records and configure the other to point to the source of the candidate records.

See the Dataflow Designer's Guide for instructions on configuring source stages.
Drag a Match Key Generator stage onto the canvas and connect it to one of the source stages.

For example, if you are using a Read from File source stage, your dataflow would now look like this:

Match Key Generator creates a non-unique key for each record, which can then be used by matching stages to identify groups of potentially duplicate records. Match keys facilitate the matching process by allowing you to group records by match key and then only comparing records within these groups.

Note: You will add a second Match Key Generator stage later. For now you only need one on the canvas.
Double-click the Match Key Generator stage.
Click Add.

Define the rule to use to generate a match key for each record.

Table 1. Match Key Generator Options
Option Name	Description and Valid Values
Algorithm	Specifies one of these algorithms to use to generate the match key: Consonant Returns specified fields with consonants removed. Double Metaphone Returns a code based on a phonetic representation of their characters. Double Metaphone is an improved version of the Metaphone algorithm, and attempts to account for the many irregularities found in different languages. Koeln Indexes names by sound as they are pronounced in German. Allows names with the same pronunciation to be encoded to the same representation so that they can be matched, despite minor differences in spelling. The result is always a sequence of numbers; special characters and white spaces are ignored. This option was developed to respond to limitations of Soundex. MD5 A message digest algorithm that produces a 128-bit hash value. This algorithm is commonly used to check data integrity. Metaphone Returns a Metaphone coded key of selected fields. Metaphone is an algorithm for coding words using their English pronunciation. SpanishMetaphone Returns a Metaphone coded key of selected fields for the Spanish language. This metaphone algorithm codes words using their Spanish pronunciation. Metaphone 3 Improves upon the Metaphone and Double Metaphone algorithms with more exact consonant and internal vowel settings that allow you to produce words or names more or less closely matched to search terms on a phonetic basis. Metaphone 3 increases the accuracy of phonetic encoding to 98%. This option was developed to respond to limitations of Soundex. Nysiis Phonetic code algorithm that matches an approximate pronunciation to an exact spelling and indexes words that are pronounced similarly. Part of the New York State Identification and Intelligence System. Say, for example, that you are looking for someone's information in a database of people. You believe that the person's name sounds like "John Smith", but it is in fact spelled "Jon Smyth". If you conducted a search looking for an exact match for "John Smith" no results would be returned. However, if you index the database using the NYSIIS algorithm and search using the NYSIIS algorithm again, the correct match will be returned because both "John Smith" and "Jon Smyth" are indexed as "JAN SNATH" by the algorithm. Phonix Preprocesses name strings by applying more than 100 transformation rules to single characters or to sequences of several characters. 19 of those rules are applied only if the characters are at the beginning of the string, while 12 of the rules are applied only if they are at the middle of the string, and 28 of the rules are applied only if they are at the end of the string. The transformed name string is encoded into a code that is comprised by a starting letter followed by three digits (removing zeros and duplicate numbers). This option was developed to respond to limitations of Soundex; it is more complex and therefore slower than Soundex. Sonnex This algorithm determines the similarity between two French-language strings based on the phonetic representation of their characters. It returns a Sonnex coded key of the selected fields. Soundex Returns a Soundex code of selected fields. Soundex produces a fixed-length code based on the English pronunciation of a word. Substring Returns a specified portion of the selected field.
Field name	Specifies the field to which you want to apply the selected algorithm to generate the match key. For example, if you select a field called LastName and you choose the Soundex algorithm, the Soundex algorithm would be applied to the data in the LastName field to produce a match key.
Start position	Specifies the starting position within the specified field. Not all algorithms allow you to specify a start position.
Length	Specifies the length of characters to include from the starting position. Not all algorithms allow you to specify a length.
Remove noise characters	Removes all non-numeric and non-alpha characters such as hyphens, white space, and other special characters from an input field.
Sort input	Sorts all characters in an input field or all terms in an input field in alphabetical order. Characters Sorts the characters values from an input field prior to creating a unique ID. Terms Sorts each term value from an input field prior to creating a unique ID.

When you are done defining the rule click OK.
Right-click the Match Key Generator stage on the canvas and select Copy Stage.
Right-click in an empty area of the canvas and select Paste.
Connect the copy of Match Key Generator to the other source stage.

For example, if you are using Read from File input stages your dataflow would now look like this:

The dataflow now contains two Match Key Generator stages that produce match keys for each source using exactly the same rules. Having identically-configured Match Key Generator stages is essential to the proper functioning of this dataflow.
Drag an Interflow Match stage onto the canvas and connect each of the Match Key Generator stages to it.

For example, if you are using Read from File input stages your dataflow would now look like this:
Double-click the Interflow Match stage.
In the Load match rule field, select one of the predefined match rules which you can either use as-is or modify to suit your needs. If you want to create a new match rule without using one of the predefined match rules as a starting point, click New. You can only have one custom rule in a dataflow.

Note: The Dataflow Options feature in Enterprise Designer enables the match rule to be exposed for configuration at runtime.
In the Group by field, select MatchKey.

This will place records that have the same match key into a group. The match rule is applied to records within a group to see if there are duplicates. The match key for each record will be generated by the Generate Match Key stages you configured earlier in this procedure.
For information about modifying the other options, see Building a Match Rule.
Drag a sink stage onto the canvas and connect it to the Interflow Match stage.

For example, if you were using a Write to File sink stage your dataflow would look like this:
Double-click the sink stage and configure it.

For information on configuring sink stages, see the Dataflow Designer's Guide.

You now have a dataflow that will match records from two data sources.

Example of Matching Records from Multiple Sources

As a direct mail company, you want to identify people who are on a do-not-mail list so that you do not send direct mail to them. You have a list of recipients in one file, and a list of people who do not wish to receive direct marketing mail in another file (a suppression file).

The following dataflow provides a solution to this business scenario:

The Read from File stage reads data from your mailing list, and the Read from File 2 stage reads data from the suppression list. The two Match Key Generator stages are identically configured so that they produce a match key which can be used by Interflow Match to form groups of potential matches. Interflow Match identifies records in the mailing list that are also in the suppression file and marks these records as duplicates. Conditional Router sends unique records, meaning those records that were not found in the suppression list, to Write to File to be written out to a file. The Conditional Router stage sends all other records to Write to Null where they are discarded.