× The internal search function is temporarily non-functional. The current search engine is no longer viable and we are researching alternatives.
As a stop gap measure, we are using Google's custom search engine service.
If you know of an easy to use, open source, search engine ... please contact support@midrange.com.



Hello Mark,

Am 30.03.2023 um 14:48 schrieb Mark Murphy <jmarkmurphy@xxxxxxxxx>:

We have a client who wants to rebuild indexes, just because they haven't
been built for a long time (3-4 years). They think it will improve
performance. I've never rebuilt indexes to improve performance. Does anyone
have an opinion on this?

In theory, any object might become fragmented on disk over time. Recreating indexes thus might increase performance.

If this theoretical increase is relevant in practice, or even measurable, I can't tell. This heavily depends on the hardware details such as disk count (and type: mechanical or SSD) of the affected ASPs, amount of RAM, etc., and on the size of the tables and indices themselves.
Probably there's also a penalty for writes, eventhough there's enough RAM to keep the index there (for reads). This also depends on usage of the tables in question, and if journalling is in use (which AFAIK buffers table writes in RAM).

Not an easy to answer question, as you can see. Being a while in this group, I can't recall coming across the topic of defragmentation on IBM i.

I disagree with Rob. I can't see how this might end up being a shoot in the foot.

:wq! PoC


As an Amazon Associate we earn from qualifying purchases.

This thread ...

Follow-Ups:
Replies:

Follow On AppleNews
Return to Archive home page | Return to MIDRANGE.COM home page

This mailing list archive is Copyright 1997-2024 by midrange.com and David Gibbs as a compilation work. Use of the archive is restricted to research of a business or technical nature. Any other uses are prohibited. Full details are available on our policy page. If you have questions about this, please contact [javascript protected email address].

Operating expenses for this site are earned using the Amazon Associate program and Google Adsense.