Eve: Building RESTful APIs with MongoDB and Flask Transcripts
Chapter: Fine-tuning your REST service
Lecture: Pagination options and performance optimizations
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As we saw endpoint pagination is enabled by default
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in order to improve performance and preserve bandwidth.
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When a client requests data, the first items matching the query are server
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and links to the next and previous pages are included with the response.
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Default page size as well as
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maximum number of allowed items per page is configurable,
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but first let's see how we can disable pagination altogether.
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Well, this is very simple we have as you now can imagine
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a boolean setting which is true by default, pagination
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we can simply turn it off like this,
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pagination is a delicate feature because it can have a huge impact
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on your server performance
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so if you don't need it for some reason, you can simply turn it off
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and clients won't be able to slow down your service at all,
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and because pagination is so important you can also set it at a local level
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for example here, I might want to have pagination
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still enabled at the people endpoint
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while I keep it disabled at the global level
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so all the other endpoints will have pagination disabled
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except for the people endpoint
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and whatever else endpoint I decide it should have it.
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Even if it is less likely to happen, you might want to change
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the word used in your queries to ask for a specific page,
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like we did with where and sort,
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you can simply set query page to whatever value you want.
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Likewise, we might want to change the word used
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to define a maximum number of items the clients would receive per page.
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The default is max results, but you can change it whatever you want.
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Now speaking of max results, it has a default value,
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if you go back to Postman and try to send a request for a single page here
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we get the items and we see that the max result is 25.
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We can change this value to whatever we please
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here we're setting the max result default value to 50 documents per page.
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You can also set a limit on these max result number
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pagination limited the setting you need for that
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and the default value is 50
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so you probably want to stay between 50 and 100 maybe
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but that might be already a bit too much, honestly.
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Pagination default again is 25
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so you want to stay around these values for your service
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unless you have a very good hardware
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and you are not very worried about pagination performance;
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or you are optimizing for pagination speed
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because there is an optional optimized pagination for speed option
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it is disabled by default but you can switch it on
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it can greatly improve performance on large collections
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but it comes with a few consequences.
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Firstly, no document count is returned with a response.
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Secondly, pagination links are less accurate as no last page link is available.
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while next page link is always included, even on the last page.
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Again, on big collections switching this feature on can greatly improve performance.
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It defaults to false for slower performance
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but document count is included, and the accurate link pages are provided.
