Oracle10g的Flashback version Query

SELECT versions_starttime, versions_endtime, versions_xid, versions_operation, a.*
FROM system_config versions BETWEEN TIMESTAMP minvalue AND maxvalue a
WHERE config_key = '***';

SELECT versions_starttime, versions_endtime, versions_xid, versions_operation, a.*
FROM system_config versions BETWEEN TIMESTAMP SYSDATE-10/24/60 AND SYSDATE a
WHERE config_key = '***'
ORDER BY nvl(versions_starttime,SYSDATE-999);

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