512cacf7c6
### What changes were proposed in this pull request?
The `RowBasedKeyValueBatch` has two different implementations depending on whether the aggregation key and value uses only fixed length data types (`FixedLengthRowBasedKeyValueBatch`) or not (`VariableLengthRowBasedKeyValueBatch`).
Before this PR the decision about the used implementation was based on by accessing the schema fields by their name.
But if two fields has the same name and one with variable length and the other with fixed length type (and all the other fields are with fixed length types) a bad decision could be made.
When `FixedLengthRowBasedKeyValueBatch` is chosen but there is a variable length field then an aggregation function could calculate with invalid values. This case is illustrated by the example used in the unit test:
`with T as (select id as a, -id as x from range(3)),
U as (select id as b, cast(id as string) as x from range(3))
select T.x, U.x, min(a) as ma, min(b) as mb from T join U on a=b group by U.x, T.x`
where the 'x' column in the left side of the join is a Long but on the right side is a String.
### Why are the changes needed?
Fixes the issue where duplicate field name aggregation has null values in the dataframe.
### Does this PR introduce _any_ user-facing change?
No
### How was this patch tested?
Added UT, tested manually on spark shell.
Closes #30788 from yliou/SPARK-33726.
Authored-by: yliou <yliou@berkeley.edu>
Signed-off-by: Wenchen Fan <wenchen@databricks.com>
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| .. | ||
| catalyst | ||
| core | ||
| hive | ||
| hive-thriftserver | ||
| create-docs.sh | ||
| gen-sql-api-docs.py | ||
| gen-sql-config-docs.py | ||
| gen-sql-functions-docs.py | ||
| mkdocs.yml | ||
| README.md | ||
Spark SQL
This module provides support for executing relational queries expressed in either SQL or the DataFrame/Dataset API.
Spark SQL is broken up into four subprojects:
- Catalyst (sql/catalyst) - An implementation-agnostic framework for manipulating trees of relational operators and expressions.
- Execution (sql/core) - A query planner / execution engine for translating Catalyst's logical query plans into Spark RDDs. This component also includes a new public interface, SQLContext, that allows users to execute SQL or LINQ statements against existing RDDs and Parquet files.
- Hive Support (sql/hive) - Includes extensions that allow users to write queries using a subset of HiveQL and access data from a Hive Metastore using Hive SerDes. There are also wrappers that allow users to run queries that include Hive UDFs, UDAFs, and UDTFs.
- HiveServer and CLI support (sql/hive-thriftserver) - Includes support for the SQL CLI (bin/spark-sql) and a HiveServer2 (for JDBC/ODBC) compatible server.
Running ./sql/create-docs.sh generates SQL documentation for built-in functions under sql/site, and SQL configuration documentation that gets included as part of configuration.md in the main docs directory.