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Date: Thu, 18 Jul 2013 09:52:48 -0400
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 <CAGxYWpZ=xpb+GrxipSkXKmJbJUDr5tW7FPte53P9gW6M3LPu7Q@mail.gmail.com>
Subject: Re: Need Strategy for Dealing with Large List Output
From: Tim Tisdall <tisdall@gmail.com>
To: user@couchdb.apache.org
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Does this help?  http://guide.couchdb.org/draft/recipes.html#pagination


On Thu, Jul 18, 2013 at 9:05 AM, Paul Roebuck <paul_roebuck@comcast.net>wrote:

> Have a couchapp whose list() can't seem to output its information
> before OS timeout  occurs. We initially just increased the OS timeout,
> but still have issues depending on whatever else is going on.
>
> What is the recommended means of paginating the output with
> multiple calls (i.e., pieces parts instead of the whole enchilada)?
>
> list(head, req) {
>     provides("json") {
>         // generate time consuming output
>     }
>     provides("xml") {
>         // generate time consuming output
>     }
> }
>
> Had initially thought of adding a response header and doing a HEAD
> call, but had problems kept getting badarg exceptions (does using
> provides() preclude using start()?).
>
> list(head, req) {
>     start({
>         headers: {
>             "X-NRows": head.total_rows
>         }
>     });
>
>     provides("json") {
>         if (req.method === 'HEAD')
>             return "";
>
>         // generate time consuming output
>     }
>     provides("xml") {
>         // generate time consuming output
>     }
> }
>
> Assuming I can retrieve this value, then the idea was to make a series
> of GETs to same list function with its view using 'limit=' and 'start=',
> collating the output using mbostock's QueueJS on HTML page prior
> to display.
>
> Or is there a better way?
>
> Thx.
>

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