Re: Locally Managed Tablespaces - any cons???

I tend to avoid locally managed tablespaces for the following reasons:

(1) A bug using the locally managed tablespaces and read only tablespaces in 8i almost prohibits using these two features together at least in 8.1.6 (see Note 131886.1 on MetaLink for more info).

(2) Once the storage parameters of the locally managed tablespace are set, they cannot be changed without rebuilding the tablespace. Setting the default storage parameters of a dictionary managed tablespace is far more flexible.

(3) Performance of queries against dba_segments appear, at least to me, to be far slower than similar queries against dictionary managed tablespaces.

Locally managed tablespaces may have a performance benefit, as others have mentioned, if there are many concurrent changes to the extents in the tablespace. I would be curious to know how volatile a tablespace has to be to justify making it locally managed rather than dictionary managed.

However, since there are costs, in at least flexibility, with using locally managed tablespaces, using them indiscriminately does not appear to be prudent.

Frank Hubeny

Ron Gardiner wrote:

> New for 8i (I believe) is locally managed tablespaces...
>
> From what I've read, sounds like there is no reason NOT to use them. Can
> they be used for all types of TS?... rollback segs, temporary, how about
> system itself?
>
> Any feedback would be appreciated!
Received on Fri Aug 17 2001 - 00:38:59 CDT