Table and index rebuild
Sergio Peres, facing fragmentation after table and index changes on versions 11.70 to 14.10, asked how to optimise rebuilds. Tom Girsch recommended the sysadmin storage optimisation tasks (repack, shrink, defragment), saying a rebuild would not do better. Sergio still saw performance problems and asked about auto_crsd and sysdistrib stress. Tom suggested running the task manually on one table. Unresolved.
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Hi,
I am having some fragmentation problems due to changes in some tables fields an indexes, as I have some system constraints and the only way to identify that I know is through dbschema, I do an export and import to optimize.
Is there any way to optimize the process?
Thanks for any help,
SP
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Sergio Peres
AIRC
Coimbra
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#Informix
What version of the engine are you running. In 11.7 and newer you should be able to use the storage optimization routines in sysadmin. ------------------------------ TOM GIRSCH ------------------------------
Hi Tom, Thanks for reply, I am using versions from 11.70 to 14.10 but I am facing some performance problems, even using sysadmin tasks... SP ------------------------------ Sergio Peres AIRC Coimbra ------------------------------
If fragmentation is really the issue, a table rebuild shouldn't fare any better than a "table defragment"; If repack->shrink->defragment doesn't solve your performance issue, I don't think a table rebuild will either. ------------------------------ TOM GIRSCH ------------------------------
Maybe I am missing something for the proccess,is it enough activate auto_crsd? There is any other task that can help me? Concerning I have several instances with sysdistrib stress, this can be related? SP ------------------------------ Sergio Peres AIRC Coimbra ------------------------------
Perhaps it's not able to keep up. I'd try running it manually against one of the impacted tables to see how long it takes and whether it completes. ------------------------------ TOM GIRSCH ------------------------------