autoextend on/db [message #57909] |
Fri, 18 July 2003 02:54 |
jack
Messages: 123 Registered: September 2000
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Senior Member |
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hi what is meant autoextend clause in createdb statement.Normally we give size of the datafile while createing a database.What will be
the advantage
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Re: autoextend on/db [message #57910 is a reply to message #57909] |
Fri, 18 July 2003 04:45 |
psmyth
Messages: 81 Registered: October 2002
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Member |
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autoextend basically does what it says. If it is set on a datafile and an object within the datafile needs to allocate another extent which would make the datafile larger than its current size, the datafile will be automaticlly increased by a specified amount, allowing the new extents to be created.
The advantage is that it allows you to make sure you don't get errors when extents cannot be allocated because a datafile has too little free space.
Now this is all well and good, as long as you are actually monitoring your database server and keep an eye on the filesystem freespace. If you are not paying attention, its entirely possible that a datafile can autoextend repeatedly until there is no more freespace in the filesystem. Personally I think thats a more difficult scenario to resolve.
So with autoextend 'on', you should be monitoring filesystem freespace regularly, and if you're doing that, you might as well be monitoring the datafile freespace, in which case setting autoextend to be on is kind of redundant.
So basically my advice is monitor freespace and next extents regularly, and use autoextend if you have huge amounts of free filesystem space.
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