There is one more good feature in oracle 10g called shrink space command. One can refer it on oracle documentation. Comments RSS. You are commenting using your WordPress. You are commenting using your Google account. You are commenting using your Twitter account. You are commenting using your Facebook account. Notify me of new comments via email. Notify me of new posts via email. Enter your email address to subscribe to this blog and receive notifications of new posts by email.
Email Address:. Of the two types of fragmentation, swiss-cheese causes the most difficulty and results in wasted database space. The SMON process automatically consolidates contiguous free extents into single large extents for tablespaces whose default value for the pctincrease storage parameter is greater than zero. This reduces but doesn't eliminate the problem. In Oracle 8i you can avoid the overhead associated with either automatic coalescence or manual coalescence by using locally managed tablespaces.
Since in a locally managed tablespace the tablespace itself tracks its extents through use of a bitmap, any contiguous free areas of space are automatically coalesced. This method will consolidate all free space, and, will consolidate all tables into single extents.
However, the database won't be available and for large systems, the time required could be extensive. You can also catch regular content via Connor's blog and Chris's blog. Or if video is more your thing, check out Connor's latest video and Chris's latest video from their Youtube channels. And of course, keep up to date with AskTOM via the official twitter account.
Questions How to find tablespace fragmentation if not use tool. Question and Answer. You Asked Hi Tom, Could you tell how to find tablespace fragmentation what is the sql statement if not use tool.
Consider This Hi Tom, We used to have 2 large tables which had data for and Now these 2 tables have been divided based on the data. The data for has been shifted to a history table and the data was shifted to new tables in a separate tablespace.
The previous tables were then renamed and the new tables were renamed to the previous ones. Then I truncated the old tables and dropped them. Now the tablespace has a lot of free spaces or fragmentation. The tablespace is LMT, so should I worry about this issue. The database version is 9iR2. May 31, - pm UTC. To me it would be lots of little odd bits and pieces of space, each a different size and shape and each perhaps totally unusable for allocating storage in that tablespace anymore.
In an LMT, that just isn't going to happen. Here is what i meant. Sorry Tom if you misunderstood or I failed to explain in a better manner. As is evident the the free blocks were at the end. As the table is LMT should I worry about it. Hope this helps. June 01, - am UTC. I understand what it looks like. I'm not understanding how it is "fragmented" as there isn't an F in the picture that is not available for use.
An LMT removes that issue. Please prove that your tablespace is fragmented as Tom said. Come with a real example as Tom shown. Post here a complete test case for us Don't just claim. And if you can't then please please please don't waste Tom's Precious time Give others a chance to ask question.
Reorganisation of LMT required? But does this LMT requires reorganisation for performance reason? Not it does not. Even if they were, you achieve nothing by having the data contigous from a performance perspective.
Tom, if I have data of one table located in LMT which is having 50 files. As of Oracle Database 10g, resolving fragmentation issues became fairly trivial. You can perform an online segment shrink using the Segment Advisor interface accessible through EM. ADDM recommends segments to shrink, and you simply choose to accept the recommendations. That is, the copying of the contents of one table to another while the original table is updated. Changes to the original table were tracked and applied to the new table.
Physical and logical attributes of the table could be changed during this online operation, thus allowing an online reorganization. Prior to Oracle9i, reducing fragmentation was more difficult.
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