spark-instrumented-optimizer/sql/core
gatorsmile 01a8e46278 [SPARK-21769][SQL] Add a table-specific option for always respecting schemas inferred/controlled by Spark SQL
## What changes were proposed in this pull request?
For Hive-serde tables, we always respect the schema stored in Hive metastore, because the schema could be altered by the other engines that share the same metastore. Thus, we always trust the metastore-controlled schema for Hive-serde tables when the schemas are different (without considering the nullability and cases). However, in some scenarios, Hive metastore also could INCORRECTLY overwrite the schemas when the serde and Hive metastore built-in serde are different.

The proposed solution is to introduce a table-specific option for such scenarios. For a specific table, users can make Spark always respect Spark-inferred/controlled schema instead of trusting metastore-controlled schema. By default, we trust Hive metastore-controlled schema.

## How was this patch tested?
Added a cross-version test case

Author: gatorsmile <gatorsmile@gmail.com>

Closes #19003 from gatorsmile/respectSparkSchema.
2017-08-22 13:12:59 -07:00
..
benchmarks [SPARK-17335][SQL] Fix ArrayType and MapType CatalogString. 2016-09-03 19:02:20 +02:00
src [SPARK-21769][SQL] Add a table-specific option for always respecting schemas inferred/controlled by Spark SQL 2017-08-22 13:12:59 -07:00
pom.xml [SPARK-21422][BUILD] Depend on Apache ORC 1.4.0 2017-08-15 23:00:13 -07:00