> It should be noted however that a unique index on timestamp will not actually enforce this rule. It will prevent duplicate values of timestamp but will not require "once a week". I would like to thank you for this detailed response. While code is above my head right now, I understand the point. I'm saving this for further use. In my case, just UNIQUE flag on timestamp will work as once a week filter, since new weekly data is generated once a week, so timestamp will always be different. If timestamp is the same, then I'm still having the same weekly data, hence needs to be ignored. Your code will come handy one day, when I will need to make sure, it runs weekly, so I'm putting it down on my 'Study ToDo' list, thanks again for all your help!