Oracle收缩表空间的步骤和方法

-- 查询表空间中的所有段
SELECT segment_type, segment_name, bytes / 1024 / 1024 AS mb
FROM dba_segments
WHERE tablespace_name = 'YOUR_TABLESPACE_NAME';

-- 查询表空间中的空闲空间
SELECT tablespace_name, sum(bytes) / 1024 / 1024 AS free_mb
FROM dba_free_space
WHERE tablespace_name = 'YOUR_TABLESPACE_NAME'
GROUP BY tablespace_name;

ALTER TABLE schema_name.table_name MOVE;

ALTER INDEX schema_name.index_name REBUILD;

BEGIN
    FOR idx IN (SELECT index_name FROM user_indexes WHERE table_name = 'TABLE_NAME') LOOP
        EXECUTE IMMEDIATE 'ALTER INDEX ' || idx.index_name || ' REBUILD';
    END LOOP;
END;
/

ALTER TABLESPACE your_tablespace_name SHRINK SPACE;

ALTER TABLESPACE your_tablespace_name SHRINK SPACE COMPACT;

ALTER DATABASE DATAFILE '/path/to/datafile.dbf' RESIZE 100M;

-- 获取表的空间使用情况
DECLARE
    used_bytes NUMBER;
    alloc_bytes NUMBER;
BEGIN
    DBMS_SPACE.OBJECT_SPACE_USAGE(
        segment_owner => 'SCHEMA_NAME',
        segment_name => 'TABLE_NAME',
        segment_type => 'TABLE',
        used_bytes => used_bytes,
        alloc_bytes => alloc_bytes
    );
    DBMS_OUTPUT.PUT_LINE('Used Bytes: ' || used_bytes);
    DBMS_OUTPUT.PUT_LINE('Allocated Bytes: ' || alloc_bytes);
END;
/

EXEC DBMS_STATS.GATHER_TABLE_STATS('SCHEMA_NAME', 'TABLE_NAME');

BEGIN
    FOR idx IN (SELECT index_name FROM user_indexes WHERE table_name = 'TABLE_NAME') LOOP
        EXECUTE IMMEDIATE 'ALTER INDEX ' || idx.index_name || ' REBUILD';
    END LOOP;
END;
/

ALTER TABLE schema_name.table_name MOVE;

@?/rdbms/admin/awrrpt.sql

ALTER SESSION SET SQL_TRACE = TRUE;
-- 执行SQL
ALTER SESSION SET SQL_TRACE = FALSE;
-- 使用tkprof分析trace文件
tkprof trace_file.trc output_file.txt