oracle 表空间维护

检查表空间大小，如果有表空间超过80%，则需要清理或扩展。查询语句：

SELECT df.tablespace_name "Tablespace",

df.bytes / (1024 * 1024) "Total Size(MB)",

SUM(fs.bytes) / (1024 * 1024) "Free Size(MB)",

round(SUM(fs.bytes) * 100 / df.bytes) "% Free",

round((df.bytes - SUM(fs.bytes)) * 100 / df.bytes) "% Used",

ROUND(100 * SQRT(MAX(fs.bytes) / SUM(fs.bytes)) * (1 / SQRT(SQRT(COUNT(fs.bytes)))), 2) "% FSFI"

FROM dba_free_space fs,

(SELECT tablespace_name,

SUM(bytes) bytes

FROM dba_data_files

GROUP BY tablespace_name) df

WHERE fs.tablespace_name = df.tablespace_name

GROUP BY df.tablespace_name,

df.bytes

注意：

如果从检查结果看，是UNDO表空间占用高，需要用下面语句再次查询，如果EXPIRED足够，UNDO空间就没有问题：

SELECT DISTINCT STATUS, SUM(BYTES), COUNT(*) FROM DBA_UNDO_EXTENTS GROUP BY STATUS;