I'm new to Hive and I wanted to know if insert overwrite will overwrite an existing table I have created. I want to filter an already created table, let's call it TableA, to only select the rows where age is greater than 18. Can I achieve this using insert overwrite table?
I'm thinking of writing something like:
INSERT OVERWRITE TABLE TableA SELECT a.Age FROM TableA WHERE a.Age > = 18
there are NA entries in the table I created, but I assume that after I filter this table there will be no NAs in the Age column, right?
Self filtering and insertion is not support , yet in hive.
I would suggest the following steps in your case :
1.Create a similar table , say tabB , with same structure.
create table tabB like tableA;
2.Then you could apply your filter and insert into this new table.
INSERT OVERWRITE TABLE tabB SELECT a.Age FROM TableA WHERE a.Age > = 18
Hope this helps.