比较两个Oracle数据库中表的数量和行数

使用Goldengate做迁移时，有时需要验证源和目标数据库中某Schema中的表的数量和行数是否一致。

可以使用以下简单的方法：

-- t.sql
set feedback off
set serveroutput on
DECLARE
val NUMBER;
BEGIN
        FOR I IN (SELECT TABLE_NAME FROM USER_TABLES order by table_name) LOOP
                EXECUTE IMMEDIATE 'SELECT count(*) FROM ' || i.table_name INTO val;
                DBMS_OUTPUT.PUT_LINE(i.table_name || chr(9) || val );
        END LOOP;
END;
/

在源和目标端分别执行，然后比较即可：

$ sqlplus -S hr/oracle@dbsrc< t.sql > src.txt
$ sqlplus -S hr/oracle@dbtgt< t.sql > tgt.txt
$ cat src.txt
COUNTRIES       25
DEPARTMENTS     27
EMPLOYEES       107
JOBS    19
JOB_HISTORY     10
LOCATIONS       23
REGIONS 4

$ diff src.txt tgt.txt

以下是有差异时的输出：

$ diff src.txt tgt.txt
2,3c2,3
< DEPARTMENTS   27
< EMPLOYEES     107
---
> DEPARTMENTS   26
> EMPLOYEES     117

$ diff -y src.txt tgt.txt
COUNTRIES       25                                              COUNTRIES       25
DEPARTMENTS     27                                            | DEPARTMENTS     26
EMPLOYEES       107                                           | EMPLOYEES       117
JOBS    19                                                      JOBS    19
JOB_HISTORY     10                                              JOB_HISTORY     10
LOCATIONS       23                                              LOCATIONS       23
REGIONS 4                                                       REGIONS 4

$ diff -y src.txt tgt.txt |grep '|'
DEPARTMENTS     27                                            | DEPARTMENTS     26
EMPLOYEES       107                                           | EMPLOYEES       117

这个脚本最大的缺陷是只能串行执行，需要改成支持并行

另一个问题是如何让DBMS_OUTPUT.PUT_LINE即时冲刷到stdout
这个问题的答案是没有，所以可以考虑将中间结果插入到临时表。

以下是产生某schema种表的列表的SQL:

-- tlist.sql
-- no column header
set heading off
-- not echo command
set echo off
-- supress terminal output
set termout off
set pages 999
-- no row count
set feedback off

spool table.lst
select table_name from user_tables;
spool off

运行如下：

$ sqlplus -S hr/oracle@orclpdb1 < tlist.sql
REGIONS
COUNTRIES
LOCATIONS
DEPARTMENTS
JOBS
EMPLOYEES
JOB_HISTORY

$ cat table.lst
REGIONS
COUNTRIES
LOCATIONS
DEPARTMENTS
JOBS
EMPLOYEES
JOB_HISTORY

如果要比较表中的内容，可以将每一行的所有列拼接，然后计算哈希值，然后将所有行的哈希值累加后比较即可。例如dbms_utility.get_hash_value

参考: http://www.dba-oracle.com/t_count_rows_all_tables_in_schema.htm