select

SYS_CONTEXT('USERENV','TERMINAL') terminal,

SYS_CONTEXT('USERENV','LANGUAGE') language,'SESSIONID') sessionid,'INSTANCE') instance,'ENTRYID') entryid,'ISDBA') isdba,'NLS_TERRITORY') nls_territory,'NLS_CURRENCY') nls_currency,'NLS_CALENDAR') nls_calendar,'NLS_DATE_formAT') nls_date_format,'NLS_DATE_LANGUAGE') nls_date_language,'NLS_SORT') nls_sort,'CURRENT_USER') current_user,'CURRENT_USERID') current_userid,'SESSION_USER') session_user,'SESSION_USERID') session_userid,'PROXY_USER') proxy_user,'PROXY_USERID') proxy_userid,'DB_DOMAIN') db_domain,'DB_NAME') db_name,'HOST') host,'OS_USER') os_user,'EXTERNAL_NAME') external_name,'IP_ADDRESS') ip_address,'NETWORK_PROTOCOL') network_protocol,'BG_JOB_ID') bg_job_id,'FG_JOB_ID') fg_job_id,'AUTHENTICATION_TYPE') authentication_type,'AUTHENTICATION_DATA') authentication_data

from dual;

转自：http://www.cnblogs.com/yudy/archive/2012/07/19/2598738.html