RE: Strange counts in onstat -u output
Any temp tables created for this query?
set explain on;
and then run the query to see what the optimizer is doing.
Does appl_no have an index in table licence? If not, that's why you are
creating a temp table and writing to it.
Regards,
Bill
> -----Original Message-----
> From: owner-informix-list@iiug.org [SMTP:owner-informix-list@iiug.org]
> On Behalf Of REBELLO, Rulesh Felix
> Sent: Thursday, March 10, 2005 11:58 AM
> To: owner-informix-list; Informix-List
> Subject: Strange counts in onstat -u output
>
> Group:
>
> I have Informix 9.40.UC3 running on Linux.
> Only one database of size approximately 500 MB
>
> I am doing the following select on 2 tables
>
> select count(*) from application a, licence b where a.appl_no => b.appl_no ;
>
> "appl_no" is serial8 datatype and is a primary key in
> "application" table.
>
>
> Table details :
>
> Table Name application
> Row Size 749
> Number of Rows 66310
> Number of Columns 32
> Index size 496
>
>
> Table Name licence
> Row Size 113
> Number of Rows 62018
> Number of Columns 19
> Index size 105
>
> When I check the onstat -u output while this query is running ...I
> get a very very high count in the "nwrites" field as compared to
> "nreads"
>
> I don't understand this ...
> The "nwrites" count is like 20 - 40 times more than the "nreads"
> count.
>
> Can somebody please throw some light on this .????
>
> regards
>
> Rulesh Rebello
>
>
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