[IMPALA-2287] Generated column names for struct fields are "."-separated.

• Type: Bug
• Status: Open
• Priority: Minor
• Resolution: Unresolved
• Affects Version/s: Impala 2.2
• Component/s: Frontend
• Labels: newbie usability
• Target Version: Product Backlog
• Assignee: Anjali Norwood
• Reporter: Tim Armstrong
• Created: 02/Sep/15 20:38
• Updated: 23/Aug/17 18:49

Description

Impala generates column names for struct paths that are the "." separated struct path. These column names are not valid column names for actual tables, which is inconvenient for CTAS, etc.

[tarmstrong-box.ca.cloudera.com:21000] > create table t (c struct<i:int>) stored as PARQUET;
Query: create table t (c struct<i:int>) stored as PARQUET

Fetched 0 row(s) in 0.07s
[tarmstrong-box.ca.cloudera.com:21000] > create table t2 as select c.i from t;
Query: create table t2 as select c.i from t
ERROR: AnalysisException: Invalid column/field name: c.i

[tarmstrong-box.ca.cloudera.com:21000] > 

Workaround
Provide an explicit column name as follows:

create table t2 as select c.i AS MY_COL_NAME from t