DBA_FLASHBACK_ARCHIVE_TS describes all tablespaces in the flashback archives available in the database.

Column Datatype NULL Description
FLASHBACK_ARCHIVE_NAME VARCHAR2(255) NOT NULL Name of the flashback archive
FLASHBACK_ARCHIVE# NUMBER NOT NULL Number of the flashback archive
TABLESPACE_NAME VARCHAR2(30) NOT NULL Name of a tablespace in the flashback archive
QUOTA_IN_MB VARCHAR2(40)   Maximum space (in MB) that can be used for Flashback Archive from the tablespace; NULL indicates no Quota restriction