Question:I am trying to fetch a count of total columns for a list of individual tables/views from Impala from the same schema.
however i wanted to scan through all the tables from that schema to capture the columns in a single query ?
i have already performed a similar excercise from Oracle Exadata ,however since i a new to Impala is there a way to capture ?
Oracle Exadata query i used
select owner, table_name as view_name, count(*) as counts from dba_tab_cols /*DBA_TABLES_COLUMNS*/ where (owner, table_name) in ( select owner, view_name from dba_views /*DBA_VIEWS*/ where 1=1 and owner='DESIRED_SCHEMA_NAME' ) group by owner ,table_name order by counts desc;
Answer:In Hive v.3.0 and up, you have
INFORMATION_SCHEMAdb that can be queried from Hue to get column info that you need.
Impala is still behind, with JIRAs IMPALA-554 Implement INFORMATION_SCHEMA in Impala and IMPALA-1761 still unresolved.
If you have better answer, please add a comment about this, thank you!