Re:I/O Is Faster Than CPU – Let’s Partition Resources and El...
by acdha on Saturday May 04, 2019 @07:11AM
(#19825749)
> Would you be willing to wait an extra five seconds for page load to be sure the banner at the bottom of "people who looked at this also looked at these" list is fully up to date and correct?
This is a separate question — do you do a live query or pre-compute it? — and it’s not really significantly easier to do that with Mongo’s model.
The pitch I saw was usually based on it being easier than having to think about your data model in advance, which is relevant to your example: everyone I know who picked it did something like that, thought it was less work and that was great, and then had some problem which came down to copies of data getting out of sync and so e.g. the “also looked at” box had the wrong price or a typo which had been fixed elsewhere. Fixing that usually cancelled out what claimed performance advantages and then some.
MongoDB's insight was that the overwhelming majority of data stores don't matter enough to justify worry about correctness. It doesn't go faster than other DBs if you turn on the "do it right" flags, but their customers mostly don't.
Would you be willing to wait an extra five seconds for page load to be sure the banner at the bottom of "people who looked at this also looked at these" list is fully up to date and correct? Or is filling the boxes with any old crap good enough?