Use the ASSUMETARGETDEFS parameter when the source and target tables specified with a MAP statement have identical column structure
It directs Oracle GoldenGate not to look up source structures from a source-definitions file.
For source and target column structures to be identical, they must:
● have identical column names (including case, if applicable)
● have identical data types
● have identical column sizes
● have the same column length semantics for character columns (bytes versus
characters)
● appear in the same order in each table
If source and target tables do not have the same structure, use the SOURCEDEFS parameter
instead of ASSUMETARGETDEFS. See “SOURCEDEFS” on page 306.