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Xiao Li e090f3c0ce [SPARK-20335][SQL] Children expressions of Hive UDF impacts the determinism of Hive UDF 
### What changes were proposed in this pull request?
```JAVA
  /**
   * Certain optimizations should not be applied if UDF is not deterministic.
   * Deterministic UDF returns same result each time it is invoked with a
   * particular input. This determinism just needs to hold within the context of
   * a query.
   *
   * return true if the UDF is deterministic
   */
  boolean deterministic() default true;
```

Based on the definition of [UDFType](https://github.com/apache/hive/blob/master/ql/src/java/org/apache/hadoop/hive/ql/udf/UDFType.java#L42-L50), when Hive UDF's children are non-deterministic, Hive UDF is also non-deterministic.

### How was this patch tested?
Added test cases.

Author: Xiao Li <gatorsmile@gmail.com>

Closes #17635 from gatorsmile/udfDeterministic.
2017-04-16 12:09:34 +08:00
..
catalyst [SPARK-19716][SQL][FOLLOW-UP] UnresolvedMapObjects should always be serializable 2017-04-16 11:14:18 +08:00
core [SPARK-20318][SQL] Use Catalyst type for min/max in ColumnStat for ease of estimation 2017-04-14 19:16:47 +08:00
hive [SPARK-20335][SQL] Children expressions of Hive UDF impacts the determinism of Hive UDF 2017-04-16 12:09:34 +08:00
hive-thriftserver [SPARK-20316][SQL] Val and Var should strictly follow the Scala syntax 2017-04-15 10:34:57 +01:00
README.md [SPARK-16557][SQL] Remove stale doc in sql/README.md 2016-07-14 19:24:42 -07:00

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.