Hi,
Is any good way to avoid error on join query with empty table?
I've come across 2 types of error as bellow.
Sample SQL:
select A.*, B.*
from cp.`tpch/nation.parquet` as A
join dfs.tmp.`dummy` as B
on A.n_nationkey = B.n_nationkey
1) When the table(file) doesn't exist.
org.apache.drill.common.exceptions.UserRemoteException: VALIDATION ERROR
Table 'TABLENAME' not found
2) When the table(file) exists, but it has no records.
ex) No recode file is created as csv with header and filled properly
header text.
such as: "n_nationkey","iso_code"
org.apache.drill.common.exceptions.UserRemoteException: SYSTEM ERROR:
DrillRuntimeException:
Join only supports implicit casts between 1. Numeric data 2.
Varchar, Varbinary data 3. Date, Timestamp data Left type: VARCHAR, Right type:
INT
Surely, I know these errors should occur in those case.
Though, we expect null values like RDB-SQL join with empty tables.
I hope your great idea.
p.s. : for your information.
Actually, we are going to query to drill in batch process.
And, we predict some tables can be empty and it's ok.
For example, temporary table is so.
We wouldn't like to suspend batch in such situation.
--
Miura, Masahide
