oracle 檔案型別總結

• Trace files: These are diagnostic files created by a server process generally in response to some exceptional error condition.

• Alert file: This is similar to a trace file, but it contains information about “expected” events, and it also alerts the DBA in a single, centralized file of many database events. The files that make up the database are

• Data files: These files are for the database; they hold your tables, indexes, and all other segments.

• Temp files: These files are used for disk-based sorts and temporary storage.

• Control files: These files tell you where the data files, temp files, and redo log files are, as well as other relevant metadata about their state.

• Redo log files: These are your transaction logs.

• Password files: These files are used to authenticate users performing administrative activities over the network. We will not discuss these files in any detail. Starting in Oracle 10g, there are a couple of new optional file types that are used by Oracle to facilitate faster backup and faster recovery operations. These two new files are

• Change tracking file: This file facilitates a true incremental backup of Oracle data. It does not have to be located in the Flash Recovery Area, but as it relates purely to database backup and recovery we’ll discuss it in the context of that area.

• Flashback log files: These files store “before images” of database blocks in order to facilitate the new FLASHBACK DATABASE command.

We’ll also take a look at other types of files commonly associated with the database,
such as

• Dump (DMP) files: These files are generated by the Export database utility and consumed by the Import database utility.

• Data Pump files: These files are generated by the new Oracle 10g Data Pump Export process and consumed by the Data Pump Import process. This file format may also be created and consumed by external tables.

• Flat files: These are plain old files you can view in a text editor. You normally use these for loading data into the database.