spark-instrumented-optimizer/docs/sql-ref.md

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title: SQL Reference
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Spark SQL is Apache Spark's module for working with structured data. This guide is a reference for Structured Query Language (SQL) and includes syntax, semantics, keywords, and examples for common SQL usage. It contains information for the following topics:

 * [ANSI Compliance](sql-ref-ansi-compliance.html)
 * [Data Types](sql-ref-datatypes.html)
 * [Datetime Pattern](sql-ref-datetime-pattern.html)
 * [Functions](sql-ref-functions.html)
   * [Built-in Functions](sql-ref-functions-builtin.html)
   * [Scalar User-Defined Functions (UDFs)](sql-ref-functions-udf-scalar.html)
   * [User-Defined Aggregate Functions (UDAFs)](sql-ref-functions-udf-aggregate.html)
   * [Integration with Hive UDFs/UDAFs/UDTFs](sql-ref-functions-udf-hive.html)
 * [Identifiers](sql-ref-identifier.html)
 * [Literals](sql-ref-literals.html)
 * [Null Semanitics](sql-ref-null-semantics.html)
 * [SQL Syntax](sql-ref-syntax.html)
   * [DDL Statements](sql-ref-syntax-ddl.html)
   * [DML Statements](sql-ref-syntax-dml.html)
   * [Data Retrieval Statements](sql-ref-syntax-qry.html)
   * [Auxiliary Statements](sql-ref-syntax-aux.html)