Row not found errors   A user deletes a row (with a given primary key value.) A second user updates or deletes the same row at another site. In this case, the second statement fails, as the row is not found.

Referential integrity errors   When a column containing a foreign key is included in a publication, but the associated primary key is not included, INSERT statements that reference the foreign key fail.

Also, referential integrity errors can occur when a primary table has a SUBSCRIBE BY expression and the associated foreign table does not: rows from the foreign table may be replicated, but the rows from the primary table may be excluded from the publication.

Duplicate primary key errors   Two users insert a row using the same primary key values, or one user updates a primary key and a second user inserts a primary key of the new value. The second operation to reach a given database in the replication system fails because it would produce a duplicate primary key.