Index related problems? Whats happening here?

All queries for a particular table seems to be slow. It has one
clustered index on the primary key column which of data type INT and
has identity insert ON. This table has < 10000 rows and is fast with
response in all other circumstances. The clustered index is at a fill
factor of 90% and I have toyed upto 70% fillfactor.
When it is slow I ran DBCC SHOWCONTIG and there were signs of
fragmentation which didn't look very serious. The BOL says it is not
reliable for smaller tables.
I run DBCC INDEXDEFRAG on a particular database. The results suggest
that there were 72 pages and 72 pages were moved and 0 deleted. Still
no improvement in performance.
I run DBCC DBREINDEX and viola query runs fast... I am happy but what
is happening here?
All help is welcome and appreciated...
ThanksDid you do a lot of updates/inserts/deletes and you didn't update statistics?
http://sqlservercode.blogspot.com/
"MasterNone" wrote:
> All queries for a particular table seems to be slow. It has one
> clustered index on the primary key column which of data type INT and
> has identity insert ON. This table has < 10000 rows and is fast with
> response in all other circumstances. The clustered index is at a fill
> factor of 90% and I have toyed upto 70% fillfactor.
> When it is slow I ran DBCC SHOWCONTIG and there were signs of
> fragmentation which didn't look very serious. The BOL says it is not
> reliable for smaller tables.
> I run DBCC INDEXDEFRAG on a particular database. The results suggest
> that there were 72 pages and 72 pages were moved and 0 deleted. Still
> no improvement in performance.
> I run DBCC DBREINDEX and viola query runs fast... I am happy but what
> is happening here?
>
> All help is welcome and appreciated...
> Thanks
>|||I had been monitoring the inserts they are of the order of 10-11 for a
table of 7500 rows. There were the same number of updates but not to
the primary key/indexed column. Currently the Autoupdate Statistics
option is turned on.|||MasterNone wrote:
> I had been monitoring the inserts they are of the order of 10-11 for a
> table of 7500 rows. There were the same number of updates but not to
> the primary key/indexed column. Currently the Autoupdate Statistics
> option is turned on.
Please post table DDL and your slow queries. You should also look at the
query plan with QA. A common cause for the phenomenon you seem to observe
is that the index is not used at all.
Regards
robert

Index Defragmentation

None of the system tables in our databases have a significant number of
pages, and I can't see there would be many scans happening, but in the
interests of completeness should system tables be defragmented if they show
high fragmentation?Hi Ben
I would say yes, they are no different to any other table in that respect
and should be optimized in a similar way. Unfortunately you can't run DBCC
INDEXDEFRAG or DBCC DBREINDEX on system tables, so you will have to hope that
the system has it's own way of keeping these tables in tune.
John
"BenUK" wrote:
> None of the system tables in our databases have a significant number of
> pages, and I can't see there would be many scans happening, but in the
> interests of completeness should system tables be defragmented if they show
> high fragmentation?
>

Index Defragmentation

None of the system tables in our databases have a significant number of
pages, and I can't see there would be many scans happening, but in the
interests of completeness should system tables be defragmented if they show
high fragmentation?Hi Ben
I would say yes, they are no different to any other table in that respect
and should be optimized in a similar way. Unfortunately you can't run DBCC
INDEXDEFRAG or DBCC DBREINDEX on system tables, so you will have to hope tha
t
the system has it's own way of keeping these tables in tune.
John
"BenUK" wrote:

> None of the system tables in our databases have a significant number of
> pages, and I can't see there would be many scans happening, but in the
> interests of completeness should system tables be defragmented if they sho
w
> high fragmentation?
>