dd4f088c1d
## What changes were proposed in this pull request? A short code snippet that uses toLocalIterator() on a dataframe produced by a RunnableCommand reproduces the problem. toLocalIterator() is called by thriftserver when `spark.sql.thriftServer.incrementalCollect`is set to handle queries producing large result set. **Before** ```SQL scala> spark.sql("show databases") res0: org.apache.spark.sql.DataFrame = [databaseName: string] scala> res0.toLocalIterator() 16/10/26 03:00:24 ERROR Executor: Exception in task 0.0 in stage 0.0 (TID 0) java.lang.ClassCastException: org.apache.spark.sql.catalyst.expressions.GenericInternalRow cannot be cast to org.apache.spark.sql.catalyst.expressions.UnsafeRow ``` **After** ```SQL scala> spark.sql("drop database databases") res30: org.apache.spark.sql.DataFrame = [] scala> spark.sql("show databases") res31: org.apache.spark.sql.DataFrame = [databaseName: string] scala> res31.toLocalIterator().asScala foreach println [default] [parquet] ``` ## How was this patch tested? Added a test in DDLSuite Author: Dilip Biswal <dbiswal@us.ibm.com> Closes #15642 from dilipbiswal/SPARK-18009. |
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catalyst | ||
core | ||
hive | ||
hive-thriftserver | ||
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 an extension of SQLContext called HiveContext that allows users to write queries using a subset of HiveQL and access data from a Hive Metastore using Hive SerDes. There are also wrappers that allows 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.