You should not use function date in "group by". So try:
select start_time,  sum(bytes)
        from
        summary
                where
                ACTIVITY in ('BACKUP','RESTORE')
                group by start_time


________________________________________
From: ADSM: Dist Stor Manager [ADSM-L AT VM.MARIST DOT EDU] On Behalf Of yoda 
woya [yodawoya AT GMAIL DOT COM]
Sent: Tuesday, March 16, 2010 8:15 PM
To: ADSM-L AT VM.MARIST DOT EDU
Subject: [ADSM-L] issue with sql syntax in TSM database

I am trying to run this sql and cannot get a result

select date(start_time),  sum(bytes)

        from
        summary

                where
                ACTIVITY = 'BACKUP'
                or ACTIVITY = 'RESTORE'

                group by date(start_time)


any reasons why??

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