kudu-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From William Berkeley <wdberke...@cloudera.com>
Subject Re: Kudu's data pagination
Date Tue, 04 Sep 2018 17:11:49 GMT
Hi Irtiza. What do you mean by paginate? I'm guessing you mean doing
something like taking the results of a query like

SELECT name, age FROM users SORT BY age DESC

and displaying the results on some UI 10 at a time, say.

If that's the case, the answer is no. It requires additional application
code. In general, Kudu cannot return rows in order. So, if you want rows
101-110, you must retrieve *all* the rows, select the top 110, and then
display only the final 10.

In special cases when the sort is on a prefix of the primary key, scan
tokens can be used to have Kudu return sorted subsets of rows from each
tablet, which you can partially merge to get the desired result set.

With a lot of data it's best to retrieve a large amount of sorted results
and paginate from the cached results, rather than running a new query per
page.

-Will

On Tue, Sep 4, 2018 at 9:02 AM Irtiza Ali <iali@an10.io> wrote:

> Hello everyone,
>
> Is there a way to paginate kudu's data using its python client?
>
>
> I
>

Mime
View raw message