index rebuilding process

Jonathan Lewis

Oldeolthof wrote:

Oracle reads the existing index in sorted order quickly creating a new index in temp degment and renaming the temp segments to the index after sucessful completion.

The general point is correct - Oracle creates a segment of type "temorary" in the target tablespace, uses the space for a new version of the index, then renames the temporary segment and drops the old index. But it could do an index full scan, an index fast full scan, or a tablescan to collect the data that allows it to create the new index.

Regards
Jonathan Lewis
http://jonathanlewis.wordpress.com
http://www.jlcomp.demon.co.uk


"Science is more than a body of knowledge; it is a way of thinking" Carl Sagan

668822

hi Jonathan,

nice to see your post, i would like to ask one question to you that does index rebuilding process cause movement of data in database??

its known that more space will be required because redo will generated... but if db require recovery will DB ask for these archive log then??

how much time it take to delete old segment after rebuilding the index??

your post is always helpful.

thanks and regards
VD

Edited by: vikrant dixit on Jan 22, 2009 3:17 AM