After the metadata for an external table is created, you can query the external data
directly and in parallel, using SQL. As a result, the external table acts as a view, which
lets you run any SQL query against external data without loading the external data
into the database.
The degree of parallel access to an external table is specified using standard parallel
hints and with the PARALLEL clause. Using parallelism on an external table allows for
concurrent access to the datafiles that comprise an external table. Whether a single file
is accessed concurrently is dependent upon the access driver implementation, and
attributes of the datafile(s) being accessed (for example, record formats).
并行访问外部表
1. 可以使用并行查询或者直接查询访问外部表元数据
来自 “ ITPUB博客 ” ，链接：https://blog.itpub.net/10599713/viewspace-981390/ ，如需转载，请注明出处，否则将追究法律责任。
-
博文量740
-
访问量2002971
最新文章
- 人力&人手&人才&人物
- oracle树中prior的用法
- Using Supplied Packages to Manage Stored Outlines
- $ORACLE_HOMERDBMSADMIN目录下各SQL的含义
- PRODUCT_USER_PROFILE Table
- Backing Up Server Parameter Files with RMAN
- Backing Up Control Files with RMAN
- Backing Up Individual Tablespaces with RMAN
- Making Whole Database Backups with RMAN
- 目睹奥运火炬传递
