查詢庫中碎片大於1G的所有表
數據總大小：DATA_LENGTH+INDEX_LENGTH
實際表空間大小： TABLE_ROWS*AVG_ROW_LENGTH
碎片大小：（DATA_LENGTH+INDEX_LENGTH-TABLE_ROWS*AVG_ROW_LENGTH）/1024/1024/1024 碎片,單位G
整理的SQL：
select TABLE_SCHEMA,TABLE_NAME,ENGINE,concat(splinter,'G') '碎片(G)' from (
SELECT TABLE_SCHEMA,TABLE_NAME,ENGINE,ROUND((DATA_LENGTH+INDEX_LENGTH-TABLE_ROWS*AVG_ROW_LENGTH)/1024/1024/1024) splinter from information_schema.`TABLES` where TABLE_TYPE='BASE TABLE'
)a WHERE splinter >1 ORDER BY splinter DESC