oracle导出数据，备份及恢复数据，及数据库日志文件的查看

以salary为例，在PLSQL Developer中操作

1.导出salary表的数据：将 salary 表的数据以 insert 语句的方式导出

                                           tools-->Export Tables-->

                                           选择左侧对象树上面的“My objects”

                                           选中要导出的表：salary

                                           选择 SQL Inserts

                                           指定导出文件的位置 Output file: D:\ salary.sql

                                           点击 Export 导出。

                                           查看导出文件内容 e:\Oracle\salary.sql

2.导出用户所有对象 DDL（数据定义语言）

                                          tools-->Export User Objects

                                          选择左边对象树上面的“My objects”

                                          选中要导出的对象，

                                          指定 Output file:e:\Oracle\ultracruiser.sql

                                          点击 Export 导出。

                                          这里可以导出如表、视图、存储过程、函数等对象。

                                          查看导出的脚本内容

3.备份及恢复：使用数据泵 expdp/impdp 来进行数据的导出导入，来达到备份/恢复、迁移的目的

      3.1.创建备份目录：不管 expdp 导出还是在 impdp 导入操作之前，必须执行以下步骤提前创建数据泵的备份目录，用来存放导出文件及日志。

            首先在系统中创建 e:\Oracle\bak 目录，然后执行以下 SQL：create or replace directory expdir as ‘e:\Oracle\bak’;

                                                                                                                       grant read,write on directory expdir to public;

                                                                                                                       commit;

      3.2 Expdp(数据导出)：导出全库：expdp system/sys full=y directory=expdir dumpfile=expdp_full.dmp logfile=expdp_full.log

                                              导出用户数据：expdp ultracruiser/ultracruiser directory=expdir dumpfile=expdp_cruiser.dmp logfile=expdp_cruiser.log

                                              导出表（salary ）：expdp ultracruiser/ultracruiser DIRECTORY=expdir DUMPFILE=expdp_salary.dmp TABLES=salary logfile=expdp_salary.log

     3.3 Impdp（数据导入）：恢复 salary ：drop table salary；（为模拟 salary 表误删除）

                                                                            impdp ultracruiser/ultracruiser DIRECTORY=expdir DUMPFILE=expdp_salary.dmp TABLES=salary logfile=impdp_salary.log

                                                   恢复用户数据：用户导出文件恢复之前，需要提前创建该用户并分配权限：create user ultracruiser identified by ultracruiser

                                                                                                                                                                                       default tablespace CRUISER_DEFAULT;

                                                                                                                                                                                        grant dba to ultracruiser

                                                                               impdp ultracruiser/ultracruiser directory=expdir dumpfile=expdp_cruiser.dmpSCHEMAS=ultracruiser logfile=impdp_cruiser.log

4.查看数据库日志文件：在 pl/sql dev 的 command windows 窗口中执行以下命令获取数据库日志路径：show parameter dump

                                           e:\oracle\diag\rdbms\test\test\trace