Creating Snapshot of Prior Day every day

[#1]

I need to calculate the difference between today's data and yesterday's data to calculate daily sales after backlog. I cannot do this after the reload because i cannot caclulate yesterday's backlog after it refreshes today. The data is not static by day.

I either need to create a table every day from yesterday's data or create a table from the pivot every day to calculate the difference between yesterday and today. Any ideas?

[fernandotoledo]

You can create a QVD with yesterday´s data.

[#3]

If you're using an incremental QVD layer, you could make the qvw create an aditional summary qvd table that updates incrementally.

Then you'll have a rolling history at summary level. You could then do day, week, month.... etc. comparisons.

[#4]

how do i do that without overwriting it each day with current data? My qview pulls the current quarter data from a csv that gets overwritten everyday

[johnw]

You could store an extra field, a load date or timestamp. Load today's data, concatenate from the QVD, store the QVD.