| PCTUSED storage parameter [message #21680] |
Thu, 22 August 2002 06:48  |
Mark
Messages: 284
Registered: July 1998
|
Senior Member |
|
|
This is an Exam 1Z0-001 question. The question says: which parameter value would you use if your table has frequent insert and deletes.
The answer says Lower PCTUSED.
But, I thought to avoid blocks with remaining empty non used space, (cause if used space is > than the default 40, new blocks are written to) the PCTUSED would need to be set to a higher value?
Thanks,
Mark
|
|
|
|
| Re: PCTUSED storage parameter [message #21683 is a reply to message #21680] |
Thu, 22 August 2002 09:53  |
andrew again
Messages: 2577
Registered: March 2000
|
Senior Member |
|
|
|
Increasing PCTUSED will result in the blocks being made available sooner for new inserts (as it will drop below PCTUSED sooner as you delete (and update records to shorter row lengths too?) rows. There is an increase in overhead to maintaining the blocks by increasing PCTUSED. Having a higher PCTUSED will result in more efficient space ulilization in your case (less space used). All of this assumes that your data is randomly distributed. If you loaded timestamped data (e.g sysdate into a field) and you deleted data older than a certain date, then your deletes would only hit the blocks with the old data, so rather than all blocks gradually decreasing in data down to PCTUSED, those specific blocks would go from "full" to "empty" in which case PCTUSED won't make much difference.
|
|
|
|
] 
Blog
Search
Help
Members
Register
Login
Home
