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查找无效对象
你可以根据这个查询结果来判断使用下面的哪种方法来编译你数据库礼貌的无效对象.

COLUMN object_name FORMAT A30 
SELECT owner, 
object_type, 
object_name, 
status 
FROM dba_objects 
WHERE status = 'INVALID' 
ORDER BY owner, object_type, object_name;

Continue reading 如何重编译ORACLE数据库的无效对象

概述
数据文件是用来存储数据库中所有逻辑结数据的物理文件,它是一个操作系统文件.我们可以用ls(UNIX/LINUX操作系统命令)在操作系统级查看到这些文件.我们在创建表空间的时候需要显式的制定数据文件.
ORACLE在创建数据文件的时候会给每个数据文件分配两个相关的文件编号, 绝对文件号(absolute file number)和相对文件号(relative file number).
绝对文件号:
在整个数据库中唯一标识数据文件.
相对文件号:
Continue reading 数据文件管理

ORA-01792 maximum number of columns in a table or view is 1000
Cause: An attempt was made to create a table or view with more than 1000 columns, or to add more columns to a table or view which pushes it over the maximum allowable limit of 1000. Note that unused columns in the table are counted toward the 1000 column limit.
Action: If the error is a result of a CREATE command, then reduce the number of columns in the command and resubmit. If the error is a result of an ALTER TABLE command, then there are two options:
* If the table contained unused columns, remove them by executing ALTER TABLE DROP UNUSED COLUMNS before adding new columns.
* Reduce the number of columns in the command and resubmit.
Continue reading ORA-017** maximum number of…

今天用户运行查询语句的时候遇到了Ora-01775错误，查看了一下帮助得到如下解释：

ORA-01775 looping chain of synonyms
Cause: Through a series of CREATE synonym statements, a synonym was defined that referred to itself. For example, the following definitions are circular:
CREATE SYNONYM s1 for s2
CREATE SYNONYM s2 for s3
CREATE SYNONYM s3 for s1
Action: Change one synonym definition so that it applies to a base table or view and retry the operation.
Continue reading Ora-01775 looping chain of synonyms