extend Paginator to support infinite pagination and postgres estimated count

[Denis Cornehl]

We often have problems with bigger tables and slow count(*) performance.

depending on the use-case there are two ways to improve the situation

• just work without count, if you never show the page-count. Then the paginator can just return empty results if the end is near.
• use rough estimations for the page-count, perhaps with some security margin. For example PostgreSQL supports this by using EXPLAIN, based on the table statistics.

I want to

• extend the paginator to support both (infinite and estimate)
• provide an option for ModelAdmin that let's you use the estimation-paginator.
• or perhaps even support the infinite-paginator, this would also include interface changes to the pagination.

[Denis Cornehl]

setting triage to accepted after discussion with Russell Keith-Magee

[Claude Paroz]

For MySQL, see also ​http://django-mysql.readthedocs.org/en/latest/queryset_extensions.html#approximate-counting
We might create a separate ticket to add the approximate count to the queryset API.

[Denis Cornehl]

thanks claudep for the mysql link, codingjoe and me had the same idea about adding this to the db-backends and queryset, and then (optionally) using it for the paginator

[Denis Cornehl]

will create a 3rd party library for this