In big data computing, besides the grouping and aggregate operations, sometimes you also need to retrieve a group of data each time to analyze. For example, to analyze the sales by date, collect statistics on sales curve for each product, and the purchase habit of each client. You can use function cs.fetch(;x) or cs.skip(;x) in esProc to get or skip records till the value of expression x is changed. By doing so, a group of consecutive data can be obtained.
Aug 11, 14