PostgreSQL FDW(Foreign Data Wrapper) 확인 점검

✅ 1. 설치된 FDW 목록 확인

SELECT * FROM pg_foreign_data_wrapper;

예시 결과

oid	fdwname	fdwowner	fdwhandler	fdwvalidator	fdwacl	fdwoptions
1234	postgres_fdw	1234	1234	1234

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✅ 2. 등록된 외부 서버(Foreign Server) 목록 확인

SELECT * FROM pg_foreign_server;

예시 결과

srvname srvowner fdwid srvoptions

oid	srvname	srvowner	srvfdw	srvtype	srvversion	srvacl	srvoptions
1234	db_server	12345	12345				{host=127.0.0.1, port=5432,dbname=db}

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✅ 3. 유저 매핑 정보 확인 (누가 외부에 접속하는지)

SELECT * FROM pg_user_mappings;

예시 결과

umid	srvid	srvname	umuser	usename	umoptions
1234	1234	db_server	0	public	{user=dbuser,password=dbuser}

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✅ 4. 외부 테이블(Foreign Table) 확인

SELECT schemaname, tablename, servername
FROM information_schema.foreign_tables;

또는 FDW 전체 목록과 조인해서 보기

SELECT
    ft.foreign_table_name,
    fs.srvname AS server_name,
    fdw.fdwname AS fdw_name
FROM
    information_schema.foreign_tables ft
JOIN
    pg_foreign_table pft ON ft.foreign_table_name = pft.ftrelid::regclass::text
JOIN
    pg_foreign_server fs ON pft.ftserver = fs.oid
JOIN
    pg_foreign_data_wrapper fdw ON fs.srvfdw = fdw.oid;

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✅ 외부 테이블에서 실제 옵션 보기 (DB, 테이블명 등)

SELECT relname AS table_name, ftoptions
FROM pg_foreign_table ft
JOIN pg_class c ON c.oid = ft.ftrelid;

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✅ 특정 외부 테이블 정의 보기

-- 뷰처럼 보려면 \d+ 사용 (psql 터미널에서)
\d+ foreign_table_name

또는

SELECT * FROM information_schema.columns WHERE table_name = 'foreign_table_name';

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💡 psql 터미널에서 FDW 빠르게 확인하는 팁

\dew        -- foreign data wrappers
\des        -- foreign servers
\deu        -- user mappings
\det        -- foreign tables

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