Re: goldengate keycols

Posted by ErmanArslansOracleBlog on Apr 16, 2021; 8:41am
URL: http://erman-arslan-s-oracle-forum.124.s1.nabble.com/goldengate-keycols-tp9626p9629.html

Without the availability of a key or KEYCOLS clause, Replicat uses all columns of the table to build its WHERE clause, essentially performing a full table scan.

Also note that,

If a target table does not have a primary key, unique key,  a unique index, Replicat does a full scan..

You use a KEYCOLS in the TABLE and MAP statements to make Replicat use the specified columns as a key. This is where you actually prevent full table scans in the absence of keys..