Eygle 是个大师

Eygle 的书深入浅出，分析充分

Eygle 的书得买正版的

推荐 此书 基于三点原因

1) 如果分不清 Instance_name, Service_name, database_name ，读此书

2) 如果想了解Oracle字符集的基本知识，很有用的只是啊，读此书

3) 如果想了解数据迁移，读此书

上周三桂问我一个问题，关于数据迁移的，据说这种业务，非常多。 读读此书吧。

置顶:《循序渐进Oracle》一书及相关信息

作者：eygle |English Version 【转载时请以超链接形式标明文章出处和作者信息及本声明】
链接：http://www.eygle.com/archives/2008/08/stepbs_oracle_info.html

PLSQL开发笔记和小结

这个同学的博客看过好几次，写的不错。推荐一下。

ORACLE EXPLAIN PLAN的总结

值得一读。Oracle的explain plan不如db2来的舒服。。。

1/If you create a table and a procedure that refers to it, and then change the
definition of the table, what will happen when you try to run the procedure?

D. The procedure may or may not compile, depending on the nature
of the change.

Ex,Oracle will attempt to recompile automatically, but this may or may not
succeed.

2/If a SELECT statement attempts to use an UNUSABLE index, what will
happen?
D. It depends on the SKIP_UNUSABLE_INDEXES parameter.
Ex,The instance parameter SKIP_UNUSABLE_INDEXES controls this behavior.
Depending on this, the statements will either fail or run by resorting to full
table scans.

3/You determine that an index is unusable, and decide to rebuild it. Which of
the following statements, if any, are correct?
B. A rebuild may require double the disk space while it is in progress
Ex, A rebuild needs space for both the old and the new index while it is in
progress.

4/You can analyze an index with the ANALYZE INDEX command, or with
the DBMS_STATS.GATHER_INDEX_STATS procedure. Which view will be
populated after this?
B. DBA_INDEXES
Ex,This view could also have been populated by analyzing the table on which
the index is based.

5/Object statistics are gathered and become out of date. What will cause them to
be gathered again?
B. You can configure a Scheduler job to gather statistics automatically.
C. You can always force the gathering of statistics by using the ANALYZE
command.
Ex,B and C. The Scheduler can be configured to run a statistics gathering job
automatically, or the statistics can be gathered interactively at any time.

6/From where are dynamic performance views populated?

A. The instance
B. The controlfile
Ex,A and B. Dynamic performance views are populated from either the instance
or the controlfile.

7/When you shut down an instance, what happens to the information in the
dynamic performance views?
A. It is lost.
Ex,A. Information in the dynamic performance views exists only for the lifetime
of the instance: it is lost on shutdown, no matter how it occurs.

8/If a primary key index becomes unusable, what will the effect be upon an
application that uses it?
A. SELECT will succeed, but perhaps at reduced performance.
Ex,A. If the SKIP_UNUSABLE_INDEXES instance parameter is on default, then
SELECT statements will still succeed, by resorting to full table scans. Most
DML statements will fail in this situation. The only exception is UPDATE
statements that do not affect the key columns.