[ 
https://issues.apache.org/jira/browse/CALCITE-4193?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17184192#comment-17184192
 ] 

Rui Wang commented on CALCITE-4193:
-----------------------------------

+1 this is a definitely useful feature. Also I think this fits into Enumerable 
interface as well so other in-memory based Enumerables shouldn't require a 
change.


My only question is how does such implementation selected during planning? E.g. 
how to know the data to be sorted will exceed the allocated memory capacity.  

> Implement new sort operator: EnumerableExternalSort
> ---------------------------------------------------
>
>                 Key: CALCITE-4193
>                 URL: https://issues.apache.org/jira/browse/CALCITE-4193
>             Project: Calcite
>          Issue Type: Improvement
>          Components: core
>            Reporter: Ruben Q L
>            Priority: Major
>
> Sometimes we need to sort a big volume of data which does not fit into 
> memory. In this situation EnumerableSort will cause an OutOfMemoryError.
> The solution for such a scenario will be using a different sorting algorithm: 
> [External Sort|https://en.wikipedia.org/wiki/External_sorting].
> The goal of the current ticket is to implement a new operator 
> (EnumerableExternalSort) to provide this feature.



--
This message was sent by Atlassian Jira
(v8.3.4#803005)

Reply via email to