1cb5bfc47a
Context: The fix for SPARK-27296 introduced by #25024 allows `Aggregator` objects to appear in queries. This works fine for aggregators with atomic input types, e.g. `Aggregator[Double, _, _]`. However it can cause a null pointer exception if the input type is `Array[_]`. This was historically considered an ignorable case for serialization of `UnresolvedMapObjects`, but the new ScalaAggregator class causes these expressions to be serialized over to executors because the resolve-and-bind is being deferred. ### What changes were proposed in this pull request? A new rule `ResolveEncodersInScalaAgg` that performs the resolution of the expressions contained in the encoders so that properly resolved expressions are serialized over to executors. ### Why are the changes needed? Applying an aggregator of the form `Aggregator[Array[_], _, _]` using `functions.udaf()` currently causes a null pointer error in Catalyst. ### Does this PR introduce _any_ user-facing change? No. ### How was this patch tested? A unit test has been added that does aggregation with array types for input, buffer, and output. I have done additional testing with my own custom aggregators in the spark REPL. Closes #28983 from erikerlandson/fix-spark-32159. Authored-by: Erik Erlandson <eerlands@redhat.com> 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.