I have a scenario here as below
TAB1 has 100Bn rows with timestamp(RPTG_TS) in 'America Pacific' and need to convert this timestamp column to GMT timestamp.
For now i have timezone shift table( Src_TZ,Tgt_TZ,from_dt,to_dt,shift), TAB1 left join Timezone on (rptg_ts between from_dt and to_dt and Src_Tz='America Pacific'
and Tgt_TZ='GMT'). But this is a inequality join, is there a best way to do this.