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https://issues.apache.org/jira/browse/DRILL-982?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Jinfeng Ni updated DRILL-982:
-----------------------------
Description:
If query a non-exist column against a parquet file, DRILL currently raises
ExecutionSetupException:
SELECT NON_EXIT_COLUMN from cp.`tpch/nation.parquet`;
This will cause problem, when we have multiple parquet files, and the first one
does not have the column, while the rest of them have the column.
It would be better to return NULL expression during execution stage, if the
columns does not exist in the parquet file.
Later on, if DRILL adds a new option to verify column existence before
executing a query ( just like what a schema-based system will do), we could
throw PlanException in planning phase, once the parquet footer information is
available to planner.
was:
If query a non-exist column against a parquet file, DRILL currently raise
ExecutionSetupException:
SELECT NON_EXIT_COLUMN from cp.`tpch/nation.parquet`;
This will cause problem, when we have multiple parquet files, and the first one
does not have the column, while the rest of them have the column.
It would be better to return NULL expression during execution stage, if the
columns does not exist in the parquet file.
Later on, if DRILL adds a new option to verify column existence before
executing a query ( just like what a schema-based system will do), we could
throw PlanException in planning phase, once the parquet footer information is
available to planner.
Summary: Parquet reader should return NULL value for non-exist column
in execution phase, in stead of raising ExecutionSetupException (was: Parquet
reader should return NULL value in execution phase, in stead of raising
ExecutionSetupException)
> Parquet reader should return NULL value for non-exist column in execution
> phase, in stead of raising ExecutionSetupException
> ----------------------------------------------------------------------------------------------------------------------------
>
> Key: DRILL-982
> URL: https://issues.apache.org/jira/browse/DRILL-982
> Project: Apache Drill
> Issue Type: Bug
> Reporter: Jinfeng Ni
> Assignee: Jason Altekruse
>
> If query a non-exist column against a parquet file, DRILL currently raises
> ExecutionSetupException:
> SELECT NON_EXIT_COLUMN from cp.`tpch/nation.parquet`;
> This will cause problem, when we have multiple parquet files, and the first
> one does not have the column, while the rest of them have the column.
>
> It would be better to return NULL expression during execution stage, if the
> columns does not exist in the parquet file.
> Later on, if DRILL adds a new option to verify column existence before
> executing a query ( just like what a schema-based system will do), we could
> throw PlanException in planning phase, once the parquet footer information is
> available to planner.
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