What is the impact of the setting EDM.MatchCountVariant?

Products

• Data Loss Prevention Enforce

Issue/Introduction

Information on how EDM.MatchCountVariant does its match count.

Resolution

Functionality V12.5 onwards: 

1 - count the number of matched database rows regardless of use of the same tokens across several matches 
2 - eliminate matches that consist of identical sets of tokens (default) 

The previous default was '3' which was removed in V12.5. Setting it to 3 did not work as documented and gave the same result as '2'.

Functionality before V12.5: 

This setting has to be either 1, 2 or 3. It determines how matches are counted.

1 - count the number of matched database rows regardless of use of the same tokens across several matches
2 - eliminate matches that consist of identical sets of tokens
3 - eliminate matches that consist of a subset of tokens from some other match (the default)

Consider a database profile that has the following three records:
Kathy, Stevens, 123-45-6789, 1111-1111-1111-1111
Kathy, Stevens, 123-45-6789, 2222-2222-2222-2222
Kathy, Stevens, 123-45-6789, 3333-3333-3333-3333

Let's say the policy rule is set up to match any 3 of 4.

If someone sends a message with the following line:
Kathy, Stevens, 123-45-6789

The matches will be counted as follows:
EDM.MatchCountVariant=1: 3 (# of database profile records matched)
EDM.MatchCountVariant=2: 1 (# of unique token sets matched)
EDM.MatchCountVariant=3: 1 (# of inclusive token sets matched)

If someone sends a message with the following 2 lines:
Kathy, Stevens, 123-45-6789, 1111-1111-1111-1111
Kathy, Stevens, 123-45-6789

The matches will be counted as follows:
EDM.MatchCountVariant=1: 3 (# of database profile records matched)
EDM.MatchCountVariant=2: 2 (# of unique token sets matched)
EDM.MatchCountVariant=3: 1 (# of inclusive token sets matched, the first token set includes the second one).