Chapter 4. Overview of Zebra Architecture

Table of Contents

1. Local Representation
2. Main Components
2.1. Core Zebra Libraries Containing Common Functionality
2.2. Zebra Indexer
2.3. Zebra Searcher/Retriever
2.4. YAZ Server Frontend
2.5. Record Models and Filter Modules
2.5.1. DOM XML Record Model and Filter Module
2.5.2. ALVIS XML Record Model and Filter Module
2.5.3. GRS-1 Record Model and Filter Modules
2.5.4. TEXT Record Model and Filter Module
3. Indexing and Retrieval Workflow
4. Retrieval of Zebra internal record data

1. Local Representation

As mentioned earlier, Zebra places few restrictions on the type of data that you can index and manage. Generally, whatever the form of the data, it is parsed by an input filter specific to that format, and turned into an internal structure that Zebra knows how to handle. This process takes place whenever the record is accessed - for indexing and retrieval.

The RecordType parameter in the zebra.cfg file, or the -t option to the indexer tells Zebra how to process input records. Two basic types of processing are available - raw text and structured data. Raw text is just that, and it is selected by providing the argument text to Zebra. Structured records are all handled internally using the basic mechanisms described in the subsequent sections. Zebra can read structured records in many different formats.