Can Symantec DLP detect on an Exact Data Match (EDM) with incomplete data where some of the fields are not filled in? How can one be sure that the data will be detected?

By default, Symantec DLP will still process rows with incomplete or incorrect data.

The setting for this is located in the ../config/Indexer.properties file:

# Whether to ignore bad rows from the data profile while creating an SDP.
# Rows are considered bad if they have more columns than expected or a column data type is incorrect.
# Set to true if bad rows should be ignored.
drop_bad_rows=false

If errors constitute a certain percentage of the data in the profile (five percent, by default), Symantec DLP stops indexing and displays an error to warn you that your data may be disorganized or corrupt.  
NOTE: DLP checks for errors only if the data source has at least a thousand rows.

Missing values (a.k.a. "row too short" errors) do not count toward either "bad rows" or the 5% threshold.  There are only two kinds of errors that count: 

- "row too long", e.g. a row has more fields than expected
- "invalid field format", e.g. an invalid SSN

 

The following value can be changed in the Enforce UI when creating the Exact Data Profile:

Error Threshold (max % of rows with errors before indexing stops)

The default is 5%, but changing this value to 100% will remove the check for bad rows.  There are no performance issues involved with making this change.