‫So, now let's talk about S3 Select
‫and Glacier Select.
‫The idea is that you know that you want to retrieve
‫a file from S3,
‫but then you're going to filter it after retrieving it,
‫and therefore you're retrieving too much data.
‫What if instead you could use SQL
‫to perform server-side filtering?
‫Therefore, that means that you're going to filter
‫by rows or by columns using simple SQL statements
‫to have less network transfers
‫and less CPU cost client-side
‫to actually go through the data and filter it.
‫So before S3 Select,
‫what you do is that you retrieve all the data
‫and then, application-side, you're going to filter it
‫to find what you need.
‫And that's a lot of data coming in
‫for only a little bit of data being used.
‫But if you use S3 Select,
‫you actually have Amazon S3 filter the file for you,
‫and you only retrieve the data you need.
‫Therefore, Amazon claims it's up to 400% faster
‫and 80% cheaper to use S3 Select.
‫Put it in another diagram,
‫we're going to want to get a CSV
‫with Amazon S3 Select, okay.
‫Amazon S3 is going to find the CSV file
‫and filter it server-side, so on its own service,
‫and then it will send us the filtered data sets
‫so that it's much smaller and much cheaper.
‫So for simple filtering, think about S3 Select
‫and that also works on Glacier, so Glacier Select.
‫That's it. I will see you in the next lecture.