Space Management in Tablespaces
Tablespace extents can be managed either by the traditional (and still default) method, wherein the information concerning free space information for the tablespace resides in the data dictionary, or through use of locally maintained bitmaps. After you have chosen a space management method, it is not easy to alter this method later.
Locally Managed Tablespaces
A tablespace has the ability, in Oracle 9i, to manage its own extents in a bitmap inside each data file. It uses this mechanism to keep track of the free and used status of the blocks in the data file. Whenever a block is used or freed for reuse, Oracle changes the value of the bitmap to show the new status of the block.
Locally managed tablespaces store ...
Get Oracle 9i Fundamentals I Exam Cram™ 2 (Exam 1Z0-031) now with the O’Reilly learning platform.
O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.
