| <?xml version="1.0" encoding="UTF-8"?> |
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| <!DOCTYPE concept PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd"> |
| <concept id="parquet_fallback_schema_resolution" rev="2.6.0 IMPALA-2835"> |
| |
| <title>PARQUET_FALLBACK_SCHEMA_RESOLUTION Query Option (<keyword keyref="impala26"/> or higher only)</title> |
| <titlealts audience="PDF"><navtitle>PARQUET FALLBACK SCHEMA RESOLUTION</navtitle></titlealts> |
| <prolog> |
| <metadata> |
| <data name="Category" value="Impala"/> |
| <data name="Category" value="Impala Query Options"/> |
| <data name="Category" value="Parquet"/> |
| <data name="Category" value="Schemas"/> |
| <data name="Category" value="Developers"/> |
| <data name="Category" value="Data Analysts"/> |
| </metadata> |
| </prolog> |
| |
| <conbody> |
| |
| <p rev="2.6.0 IMPALA-2835"> |
| <indexterm audience="hidden">PARQUET_FALLBACK_SCHEMA_RESOLUTION query option</indexterm> |
| The <codeph>PARQUET_FALLBACK_SCHEMA_RESOLUTION</codeph> query option allows Impala to look |
| up columns within Parquet files by column name, rather than column order, |
| when necessary. |
| The allowed values are: |
| <ul> |
| <li> |
| POSITION (0) |
| </li> |
| <li> |
| NAME (1) |
| </li> |
| </ul> |
| </p> |
| |
| <p conref="../shared/impala_common.xml#common/usage_notes_blurb"/> |
| <p> |
| By default, Impala looks up columns within a Parquet file based on |
| the order of columns in the table. |
| The <codeph>name</codeph> setting for this option enables behavior for |
| Impala queries similar to the Hive setting <codeph>parquet.column.index access=false</codeph>. |
| It also allows Impala to query Parquet files created by Hive with the |
| <codeph>parquet.column.index.access=false</codeph> setting in effect. |
| </p> |
| |
| <p> |
| <b>Type:</b> integer or string |
| </p> |
| |
| <p conref="../shared/impala_common.xml#common/added_in_260"/> |
| |
| <p conref="../shared/impala_common.xml#common/related_info"/> |
| <p> |
| <xref href="impala_parquet.xml#parquet_schema_evolution"/> |
| </p> |
| |
| </conbody> |
| </concept> |