Mapping problem with compressed update record (target format)...

One of the group abanded and ggserror.log says:
ERROR   OGG-01296  Oracle GoldenGate Delivery for Oracle, RRHP03.prm:  Error mapping from schema_name.table_name to schema_name.table_name

Discard file says:

Key column column_name (8) is missing from update on table table_name.column_name
and the list continues for all the columns in the table and:
Missing 46 key columns in update for table schema_name.table_name.
Current time: 2014-05-11 12:32:11
Discarded record from action ABEND on error 0


Aborting transaction on dirdat/rc beginning at seqno 63 rba 194046251
                         error at seqno 63 rba 194046975
Problem replicating schema_name.table_name to schema_name.table_name
Mapping problem with compressed update record (target format)...

Well, this table has UNIQUE INDEX defined at the source but somehow that index is missing at the target.
So, created that index at the target and also added this to parameter file to make sure that index column is being used instead of looking for the complete set of columns for the uniqueness.

map schema_name.table_name, target schema_name.table_name, keycols (unique_index_columns) ;

More details for different scenarios:

Replicat Abending With Mapping Error and discard file shows Missing Key Columns (Doc ID 1276538.1)