--工作中有时候需要使用SYS_CONTEXT 函数，查手册有一些慢，做一个记录：

 

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

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