Re: Does index be used when doing "join" operation between a big table and a small table?
Except the number of tasks, can we confirm whether to use index from the log file? Such as something like keyword for us to search in the log file directly. - FFCS研究院 -- Sent from: http://apache-carbondata-dev-mailing-list-archive.1130556.n5.nabble.com/
Re: Does index be used when doing "join" operation between a big table and a small table?
If the index be used, the number of tasks would be less. Can you share your script (create table script and query script), let us check if you created the effective index for filter columns. Regards Liang -- Sent from: http://apache-carbondata-dev-mailing-list-archive.1130556.n5.nabble.com/
Re: Does index be used when doing "join" operation between a big table and a small table?
Hi If the index be used for filtering data, the number of tasks would be more less. Can you share the script(create table and query), let us check if created the effective index for filter columns. Regards Liang Mic Sun wrote > hello， > > I have 2 tables need to do "join" operation by their primary key, the > primary key of these 2 tables are both type "String". > > There are 200 million pieces of data in the big table and only 20 > throusand pieces of data in the small table. > > This join operation is quite slow. > I want to know does index be used when doing "join" operation between a > big table and a small table? > > And how to confirm whether index be used? > > > > > sunerhan1992@ -- Sent from: http://apache-carbondata-dev-mailing-list-archive.1130556.n5.nabble.com/
