ORACLE中查找用户表和用户表字段等

select table_name,num_rows from all_tables where OWNER='TIGER' AND TABLE_NAME like '%MASTER'
order by num_rows desc

select * from user_tab_columns
where DATA_TYPE='CHAR' and DATA_LENGTH=119
and Table_name=upper('TYIMBLMASTER')

select count(*) from sys_data
where trxref in (select trxref from sys_data group by trxref having count(trxref) > 1)
--或
select sum(n) from (select trxref,count(trxref) as n from sys_datas group by trxref having count(trxref) > 1)

select count(trxref) from (select trxref,count(trxref) as n from sys_data group by trxref having count(trxref) > 1)

select count(*) from sys_data
where trxref in (select trxref from sys_datas group by trxref having count(trxref) > 1)
and rowid not in (select min(rowid) from   sys_data group by trxref having count(trxref)>1)

delete from sys_data
where trxref in (select trxref from sys_data group by trxref having count(trxref) > 1)
and rowid not in (select min(rowid) from   sys_data