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Re: [DISCUSSION] Support Map type for complex type columns

Posted by Indhumathi on Aug 21, 2018; 5:33am
URL: http://apache-carbondata-dev-mailing-list-archive.168.s1.nabble.com/DISCUSSION-Support-Map-type-for-complex-type-columns-tp59720p59875.html

Hi Chetan,

Thanks for your review. Please find my comments inline.

1. Will lucene datamap and MV datamap be able to be created with map type. ?

** No. This has been updated in Design Document. Please check **

2. Can COLUMN_META_CACHE ,NO_INVERTED_INDEX and bucketing table properties
be configured for map type column. ?

** No. Same behavior as that of Struct and Array **

3. Currently carbon supports 2 level complex type schema for csv and n level
for avro. Will the same be supported for map type as well ?

** Yes. Similar to Array and Struct, Map will also support 2 level complex
type schema
    for csv and n level for avro **

4. Dictionary include/exclude for complex type child columns is not
supported now. Will the same apply for map type as well ?

** Yes. Same behavior as that of Array and Struct. **

5. In the design doc its mentioned that Local Dictionary for Map Datatype
column has to be supported. However in case of multi-level complex dataType
columns, primitive string/varchar/char columns are
considered for local dictionary generation. Please confirm the behavior to
be supported.

** Internally, Map will be stored as Array<Struct&lt;key, values>>, hence
behavior will
   be same as that of Struct and Array. **

Please find the updated Design document for Map -Datatype support
MAP_DATA-TYPE_SUPPORT.pdf
<http://apache-carbondata-dev-mailing-list-archive.1130556.n5.nabble.com/file/t341/MAP_DATA-TYPE_SUPPORT.pdf>  



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