Re: [DISCUSSION] support user specified segment reading for query

Hi Rahul I suggest only doing "Query HINT". Please finalize the query script : select * from t1 [in SEGMENTS(1,3,5)] or SELECT /*+SEGMENTS(1,3,5) */ from t1 Regards Liang -- Sent from: http://apache-carbondata-dev-mailing-list-archive.1130556.n5.nabble.com/

Re: [DISCUSSION] support user specified segment reading for query

Thanks @Raghunandan for updating the use case. As i have analyzed UnresolvedHint is supported with Spark-2.2. So we can support Query-Hint once spark2.2 integration is completed. Jira( CARBONDATA-1546 ) is already raised for QueryHint.

Re: [DISCUSSION] support user specified segment reading for query

Hi Rahul, I agree query hint is better. The syntax from Ravi is the same with Oracle, which is more popular and acceptable I think... Show Segments statement could remove 'For table', just 'show segments [dbname].'. It's simple and same style with show partition statement... Thanks, Lionel Cao

Re: [DISCUSSION] support user specified segment reading for query

Hi, Instead of using SET command to use for segments why don't you use QUERY HINT . Using query hint we can mention the segments inside the query itself as a hint. For example SELECT /*+SEGMENTS(1,3,5) */ from t1. By using the above custom hint we can query from selected segments only, This

Re: [DISCUSSION] support user specified segment reading for query

@Jacky please find the reply of your doubts as follow : *1.If user uses following command in two different beeline session, will there be problem due to multithreading? SET carbon.input.segments.default.* *carbontable=1,3,5; select * from carbontable; SET

Re: [DISCUSSION] support user specified segment reading for query

I have 2 doubts: 1. If user uses following command in two different beeline session, will there be problem due to multithreading? SET carbon.input.segments.default.carbontable=1,3,5; select * from carbontable; SET carbon.input.segments.default.carbontable=*; 2. The RESET command is not clear,