Re: [Discussion]: option to disable multi-layered index scan and use full table scan

Posted by Liang Chen on Sep 27, 2016; 11:43pm
URL: http://apache-carbondata-dev-mailing-list-archive.168.s1.nabble.com/Discussion-option-to-disable-multi-layered-index-scan-and-use-full-table-scan-tp1526p1528.html

Hi

good suggestion!
Add one configurable option to disable index for no filter and small table
scenarios.
One comment : you are suggesting only disable MDK; How about other
index(inverted index,and MINMAX index)?

+1 for this feature

Regards
Liang

2016-09-28 6:49 GMT+08:00 Aniket Adnaik <[hidden email]>:

> Carbondata can provide some way to disable usage of multi-layered index and
> provide full table scan.
> This may help in following cases;
> 1. Small tables occupying only few number of blocks are probably better of
> using full table scan.
> 2. Queries with large number of projections with no filter may benefit from
> using full table scan.
> 3. Testing different scenarios and comparing with multiple HDFS file
> formats
> that do not provide multi layer index will be easier.
>
> Also, Carbondata scan internally should be smart enough to detect this
> based
> on query, data size, etc.
>
> Any comments?
>
>
>
>
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>

--

Regards
Liang