spark-instrumented-optimizer/sql
Wang Gengliang 3cb3ccce12 [SPARK-21196] Split codegen info of query plan into sequence
codegen info of query plan can be very long.
In debugging console / web page, it would be more readable if the subtrees and corresponding codegen are split into sequence.

Example:

```java
codegenStringSeq(sql("select 1").queryExecution.executedPlan)
```
The example will return Seq[(String, String)] of length 1, containing the subtree as string and the corresponding generated code.

The subtree as string:

> (*Project [1 AS 1#0]
> +- Scan OneRowRelation[]

The generated code:
```java
/* 001 */ public Object generate(Object[] references) {
/* 002 */   return new GeneratedIterator(references);
/* 003 */ }
/* 004 */
/* 005 */ final class GeneratedIterator extends org.apache.spark.sql.execution.BufferedRowIterator {
/* 006 */   private Object[] references;
/* 007 */   private scala.collection.Iterator[] inputs;
/* 008 */   private scala.collection.Iterator inputadapter_input;
/* 009 */   private UnsafeRow project_result;
/* 010 */   private org.apache.spark.sql.catalyst.expressions.codegen.BufferHolder project_holder;
/* 011 */   private org.apache.spark.sql.catalyst.expressions.codegen.UnsafeRowWriter project_rowWriter;
/* 012 */
/* 013 */   public GeneratedIterator(Object[] references) {
/* 014 */     this.references = references;
/* 015 */   }
/* 016 */
/* 017 */   public void init(int index, scala.collection.Iterator[] inputs) {
/* 018 */     partitionIndex = index;
/* 019 */     this.inputs = inputs;
/* 020 */     inputadapter_input = inputs[0];
/* 021 */     project_result = new UnsafeRow(1);
/* 022 */     project_holder = new org.apache.spark.sql.catalyst.expressions.codegen.BufferHolder(project_result, 0);
/* 023 */     project_rowWriter = new org.apache.spark.sql.catalyst.expressions.codegen.UnsafeRowWriter(project_holder, 1);
/* 024 */
/* 025 */   }
/* 026 */
/* 027 */   protected void processNext() throws java.io.IOException {
/* 028 */     while (inputadapter_input.hasNext() && !stopEarly()) {
/* 029 */       InternalRow inputadapter_row = (InternalRow) inputadapter_input.next();
/* 030 */       project_rowWriter.write(0, 1);
/* 031 */       append(project_result);
/* 032 */       if (shouldStop()) return;
/* 033 */     }
/* 034 */   }
/* 035 */
/* 036 */ }
```
## What changes were proposed in this pull request?
add method codegenToSeq: split codegen info of query plan into sequence

## How was this patch tested?
unit test

cloud-fan gatorsmile
Please review http://spark.apache.org/contributing.html before opening a pull request.

Author: Wang Gengliang <ltnwgl@gmail.com>

Closes #18409 from gengliangwang/codegen.
2017-06-27 17:24:46 +08:00
..
catalyst [SPARK-21153] Use project instead of expand in tumbling windows 2017-06-26 01:26:32 -07:00
core [SPARK-21196] Split codegen info of query plan into sequence 2017-06-27 17:24:46 +08:00
hive [HOT FIX] fix stats functions in the recent patch 2017-06-25 15:06:29 +01:00
hive-thriftserver [SPARK-20345][SQL] Fix STS error handling logic on HiveSQLException 2017-06-12 14:05:03 -07:00
README.md [SPARK-16557][SQL] Remove stale doc in sql/README.md 2016-07-14 19:24:42 -07:00

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.