https://community.cloudera.com/t5/Support-Questions/What-is-col0-in-hive-explain-plan/m-p/191215#M153304 <P>Hi <A rel="user" href="https://community.cloudera.com/users/11675/mattliem.html" nodeid="11675">@Nick Xu</A>. _col0 is the first column in the table definition. You can find out what it is by running "DESCRIBE &lt;tablename&gt;"</P> Tue, 15 May 2018 19:31:36 GMT SQLShaw 2018-05-15T19:31:36Z