mqliang opened a new issue #6708: URL: https://github.com/apache/incubator-pinot/issues/6708
Pinot supports two types of transform functions: * Scalar transforms * Non-scalar transforms Scalar transform take in a scalar (string, int etc) value and output a scalar value. For example, now() was added as a scalar transform function to return the current timestamp as milliseconds from epoch We should consider adding another scalar function ago(timespan) which subtracts the given timespan time from the current timestamp E.g * ago(1h) should subtract 1 hour from current time * ago(1d) should subtract 1 day from current time We can then potentially use it in filter clauses as WHERE timeCol > ago(1h) -> this will return all rows with time in the last 1 hour. The current alternative to do this is WHERE timeCol > toEpochHours(now()) - 1 But ago() can also be a good addition to our list of inbuilt scalar functions Considerations * See how the interval passed to ago() as argument should be specified. * What should be the return value of ago() ? Always millisSinceEpoch or the value corresponding to the unit passed in the argument ? For example, if the user passes ago(1h) then it subtracts 1 hour from the current time and returns the value as hoursSinceEpoch. Similarly, if the user does ago(1d), then it subtracts 1 day from the current time and returns the value as daysSinceEpoch. * What happens if the timeCol we are comparing with is not in the same units ? For example, if user is doing WHERE timeCol > ago(1h) then it is expected that timeCol has values in hoursSinceEpoch. Looks like this and previous point are somewhat related cc @siddharthteotia -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: commits-unsubscr...@pinot.apache.org For additional commands, e-mail: commits-h...@pinot.apache.org
