Hi Andries, Where does it say that the query for an non existing file is unions/joins should fail?
I ask because I'm interested in the "basic rules of Drill". Rgards, -Stefán On Fri, Dec 18, 2015 at 4:37 PM, Andries Engelbrecht < aengelbre...@maprtech.com> wrote: > 1) When the table/file doesn't exist it should fail. > > 2) If the file is empty Drill is trying to discover a schema, but unable > to do so since there are no records. Perhaps try to create a View on these > "temp" tables so you can declare dat types used of joins. This way at least > you give Drill a data type for the JOIN even if the file has no data. > > --Andries > > > On Dec 17, 2015, at 9:39 PM, <masahide.mi...@brother.co.jp> < > masahide.mi...@brother.co.jp> wrote: > > > > 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 > > > >
