How to rebuild a lob index in oracle normally you cannot move or rebuild a lob index to another tablespace like normal table. Yes, i have rebuild that index using below query, but that index size is increased. Alter index rebuild oracle database administration. Say you want to find all the female gold medal winners in the 2000 athens olympics. How to move a lob segment and a lob index to a differrent tablespace. Use the alter index statement to change or rebuild an existing index. For an online rebuild operation alter index rebuild online, performs cleanup operations on tables associated with the older version of the index.
Changes the initial number of transaction entries allocated to each block of the index. Oracle database provides you with the opportunity to collect statistics at very little resource cost during the creation or rebuilding of an index. Script to rebuild indexes it is very difficult to write a script that will identify indexes that will benefit from rebuilding because it depends on how the indexes are used. I have recommended people to read toms books and oracle docs instead. The purpose of the sql server index is pretty much the same as in its distant relative the book index it allows you to get to the information. Tech17 1, techfest19 1, the dark side of the moon 1, top 100 books 1, total recall 1. The only danger with using nologging is that you must rerun the create index syntax if you perform a rollforward database recovery. Altering indexes oracle database online documentation 11g. Name alter index rebuild partition synopsis alter index schema. Rebuilds a spatial index or a specified partition of a partitioned index. Changes the maximum number of transaction entries allocated to each block of the index. How to create and use indexes in oracle database oracle. Developers and dbas get help from oracle experts on.
Forces oracle to rebuild the index using information in that index. If index is a local index on a compositepartitioned table, oracle database. When do i consider adding the online argument to a rebuild index statement. Fastest way to rebuild oracle index burleson consulting. Oracle btree indexes can become unbalanced and need to be rebuilt is a myth 3. This means indexes which point to a large number of rows can still be useful. Oracle database sql reference for syntax and restrictions on the use of the create. The alter index command is detailed in the sql reference manual, in the documentation on instead of filling pages with syntax and. By overlaying the rowid ranges of two indexes, you can find which rows match the where clause in both. While it is tempting to write a script that rebuilds every index in the schema.
I also have more sophisticated index rebuilding scripts in my book oracle tuning. Posts about index rebuild written by richard foote. Why, when and how to rebuild and reorganize sql server indexes. These statistics are stored in the data dictionary for ongoing use by the optimizer in choosing a plan for the execution of sql statements. If an index has a height of x levels, its inefficient and must be rebuilt is a myth 5. After all, however many benchmark examples someone like you could come up with.