Unable to read the schema version from the schema info table.

Tryin to export Openstreetmap Postgres sql to pbf

osmosis --rs host="localhost" database="openstreetmap" user="osm" password="osm" outPipe.0=pg --dd inPipe.0=pg outPipe.0=dd --write-pbf inPipe.0=dd file=myfile.osm.pbf

and getting error

org.openstreetmap.osmosis.core.OsmosisRuntimeException: Unable to read the schema version from the schema info table.
Caused by: org.postgresql.util.PSQLException: ERROR: relation "schema_info" does not exist