Specifies the string of characters that replace leading underscores used in identifiers for collections, documents, and arrays.
Valid Values
string
where:
string
is comprised of any Unicode character or group of characters, including spaces.
Example
MongoDB collections automatically include the _id field. By specifying LeadingUnderscoreReplacement=XX, the _id field becomes the XXID column in the relational view of the data. In addition, any other fields or collections with a leading underscore would be modified in the same manner.
Notes
The Schema Tool builds table and column identifiers by concatenating the names of nested collections, documents, and arrays. When specifying a value for LeadingUnderscoreReplacement, consider that the total length of identifiers must not exceed 128 characters in length.