Oracle Database 18c is the terminal release for support of the Oracle Streams feature. Oracle Streams will be desupported from Oracle Database 19 onwards.
Oracle Streams was deprecated in Oracle Database 12c (12.1). It does not support features introduced in Database version 12.1 and later releases, including the multitenant architecture, the LONG VARCHAR data type, long identifiers, and other features. Oracle GoldenGate is the replication solution for Oracle Database.