1. 查询实例下所有表的行数：
   需要收集过统计信息。

--CALL SP_DB_STAT_INIT ();

SELECT
        TABLE_NAME      AS 表名   ,
        OWNER           AS 所属用户 ,
        TABLESPACE_NAME AS 所属表空间,
        NUM_ROWS        AS 行数
FROM
        DBA_TABLES
WHERE
        OWNER NOT IN ('SYS', 'SYSTEM', 'SYSAUDITOR', 'SYSJOB', 'SYSSSO', 'CTISYS')
    AND TABLESPACE_NAME != 'TEMP';

2. 查看每个schema大小，可以将每个schema放在单独表空间中，固定间隔查看表空间大小；或固定每年查询表大小+索引大小

所有schema表占用空间

SELECT
        SUM(A.BYTES/1024/1024)
        ||' MB' AS TOTAL_SIZE
FROM
        DBA_SEGMENTS A
WHERE
        OWNER = 'BENCH';

所有索引占用空间

SELECT
        SUM(INDEX_USED_PAGES(S.ID)*(PAGE/1024))/1024
        ||' MB' AS TOTAL_SPACE
FROM
        (
                SELECT
                        TABLE_NAME,
                        INDEX_NAME,
                        INDEX_TYPE
                FROM
                        DBA_INDEXES
                WHERE
                        OWNER = 'BENCH'
        )
        DBAIDX,
        (
                SELECT ID, NAME FROM SYSOBJECTS S WHERE S.SUBTYPE$ = 'INDEX'
        )
        S
WHERE
        DBAIDX.INDEX_NAME = S.NAME;