Re: Fractured Indicies

Naomi Walker says: > How can I tell how fractured an index has become? I've been experimenting > with tbcheck -pk, and tbcheck -pT, but cant convince myself of anything. I am not sure what you mean by a "fractured" index. As I understand it, the indexes are kept in order dynamically as rows are added or deleted. However, the records will not be necessarily in a physical order which follows the index. I'm proceeding under the assumption that you want the physical order of the rows of a table to match an index on that table. > If I tbunload/tbload an entire database, will indicies be rebuilt, > and therefore, unfractured? I suspect that tbload will build the database back with the same order to the rows as when they were tbunloaded, however, if a table has been interleaved with other tables, that table may load back in into a contiguous space on the disk as long as there is a big enough contiguous space available. This will not guarantee that the physical order will match the index. You can "alter index index-name to cluster". This WILL reorganize the data so the physical order will follow this index. However, at the first update, add, delete, this order will begin to be "fractured" again. Also, this command may take quite a while on a large table, and will have to be run on each index individually (only one index per table, or you will undo what you did on the previous index on that table). See the Alter Index command in the manual for further details about use and space requirements. -- Bryan Klopfenstein try: bryan@cinnet.com CARS Information Systems, Inc. or: ..uunet!uceng!cinnet!carsinfo!bryan Cincinnati, OH better: usr10300@tso.uc.edu Standard Disclaimers Apply