Developer's Guide to the Enhanced Vector Framework - apache/drill GitHub Wiki

The Enhanced Vector Framework (EVF) provides a complete set of tools to create and read from batches of vectors. This guide explains how to use the framework to create scan operators and file format readers. See Batch Handling Upgrades for the design and internal details.

Basic Tutorial

Read this section to get going in a hurry. The tutorial is split into chunks for easier reading. The first sections discuss the bare minimum to convert a plugin to EVF:

• Overview
• Plugin Revisions
• Row Batch Reader
• Define the Scan Framework

Extended Tutorial

EVF provides several additional features to improve your plugin:

• Advanced Configuration
• Special Columns
• Type Conversion
• Support an External Schema
• Override Plugin Config Properties with Table Schema
• Enhanced Error Reporting
• Discover Schema While Reading

Reference Information

Read this section to gain a deeper understanding and exploit advanced features.

• Introduction
• Creating and Reading Record Batches
• Reading and Writing Value Vectors
• Memory Management
• Memory-Controlled Writes
• Projection
• Type Conversion
• Scan Framework