데이터 검색
ANSI 표준 SQL로 데이터를 검색할 수 있습니다.
다음 예제는 인덱스를 생성하지 않은 상태에서의 검색을 보여줍니다.
즉, 마지막에 입력된 데이터가 먼저 출력됩니다.
자세한 내용은 SQL Reference의 SELECT 섹션을 참조하세요.
기본 검색
SELECT * FROM table_name;Index
Basic access
View Conditional Clause
Mach> SELECT * FROM mach_log;
DEVICE TM TEMP
----------------------------------------------------------------
MSG
------------------------------------------------------------------------------------
192.168.0.1 NULL NULL
NULL
192.168.0.2 2014-06-15 19:50:03 484:382:010 82
error code = 20, critical warning
192.168.0.2 2014-06-15 19:50:03 484:382:008 57
error code = 20
192.168.0.1 2014-06-15 19:50:03 484:382:006 99
error code = 10, critical bug
192.168.0.1 2014-06-15 19:50:03 484:382:004 55
error code = 10
192.168.0.2 2014-06-15 19:50:03 484:382:002 31
normal state
192.168.0.1 2014-06-15 19:50:03 484:382:000 32
normal state
[7] row(s) selected.
Mach>조건절 검색
SELECT column_name,column_name
FROM table_name
WHERE column_name operator value;Mach> SELECT * FROM mach_log WHERE device = '192.168.0.1';
DEVICE TM TEMP
----------------------------------------------------------------
MSG
------------------------------------------------------------------------------------
192.168.0.1 NULL NULL
NULL
192.168.0.1 2014-06-15 19:50:36 488:663:006 99
error code = 10, critical bug
192.168.0.1 2014-06-15 19:50:36 488:663:004 55
error code = 10
192.168.0.1 2014-06-15 19:50:36 488:663:000 32
normal state
[4] row(s) selected.
Mach> SELECT * FROM mach_log WHERE device = '192.168.0.1' AND temp > 30 AND temp < 50;
DEVICE TM TEMP
----------------------------------------------------------------
MSG
------------------------------------------------------------------------------------
192.168.0.1 2014-06-15 19:50:36 488:663:000 32
normal state
[1] row(s) selected.
Mach> SELECT * FROM mach_log where device > '192.168.0.1';
DEVICE TM TEMP
----------------------------------------------------------------
MSG
------------------------------------------------------------------------------------
192.168.0.2 2014-06-15 19:50:36 488:663:010 82
error code = 20, critical warning
192.168.0.2 2014-06-15 19:50:36 488:663:008 57
error code = 20
192.168.0.2 2014-06-15 19:50:36 488:663:002 31
normal state
[3] row(s) selected.
Mach> SELECT * FROM mach_log WHERE msg LIKE '%error%';
DEVICE TM TEMP
----------------------------------------------------------------
MSG
------------------------------------------------------------------------------------
192.168.0.2 2014-06-15 19:50:36 488:663:010 82
error code = 20, critical warning
192.168.0.2 2014-06-15 19:50:36 488:663:008 57
error code = 20
192.168.0.1 2014-06-15 19:50:36 488:663:006 99
error code = 10, critical bug
192.168.0.1 2014-06-15 19:50:36 488:663:004 55
error code = 10
[4] row(s) selected.힌트를 사용한 검색 방향 지정
역방향
기본값이며, /*+ SCAN_BACKWARD(table_name) */ 힌트를 추가하여 검색할 수 있습니다.
Mach> SELECT * FROM LOG;
TIME
----------------------------------
2021-01-04 00:00:00 000:000:000
2021-01-03 00:00:00 000:000:000
2021-01-02 00:00:00 000:000:000
2021-01-01 00:00:00 000:000:000
[4] row(s) selected.
Elapsed time: 0.001
Mach> SELECT /*+ SCAN_BACKWARD(LOG) */ * FROM LOG;
TIME
----------------------------------
2021-01-04 00:00:00 000:000:000
2021-01-03 00:00:00 000:000:000
2021-01-02 00:00:00 000:000:000
2021-01-01 00:00:00 000:000:000
[4] row(s) selected.
Elapsed time: 0.001정방향
/*+ SCAN_FORWARD(table_name) */ 힌트를 사용하여 정방향으로 검색합니다.
Mach> SELECT /*+ SCAN_FORWARD(LOG) */ * FROM LOG;
TIME
----------------------------------
2021-01-01 00:00:00 000:000:000
2021-01-02 00:00:00 000:000:000
2021-01-03 00:00:00 000:000:000
2021-01-04 00:00:00 000:000:000
[4] row(s) selected.
Elapsed time: 0.001기본 스캔 방향을 설정하는 프로퍼티
TABLE_SCAN_DIRECTION 프로퍼티를 사용하면 SELECT 문에 힌트가 없을 때 Log 테이블의 스캔 방향을 설정할 수 있습니다.
최근 업데이트