Issue Tracking

Issue tracking at github.

System Requirements

Sun JDK 5 or higher is recommended.

Couchdb-lucene is known to be incompatible with some versions of OpenJDK as it includes an earlier, and incompatible, version of the Rhino Javascript library. The version in Ubuntu 8.10 (6b12-0ubuntu6.4) is known to work and it uses Rhino 1.7R1.

Build couchdb-lucene

1. Install Maven 2.
2. checkout repository
3. type 'mvn'
4. configure couchdb (see below)

Configure CouchDB

[couchdb]
os_process_timeout=60000 ; increase the timeout from 5 seconds.
[external]
fti=/usr/bin/java -server -jar /path/to/couchdb-lucene*-jar-with-dependencies.jar -search
[update_notification]
indexer=/usr/bin/java -server -jar /path/to/couchdb-lucene*-jar-with-dependencies.jar -index
[httpd_db_handlers]
_fti = {couch_httpd_external, handle_external_req, <<"fti">>}

Indexing Strategy

Document Indexing

You must supply a index function in order to enable couchdb-lucene as, by default, nothing will be indexed. To suppress a document from the index, return null. It's more typical to return a single Document object which contains everything you'd like to query and retrieve. You may also return an array of Document objects if you wish.

You may add any number of index views in any number of design documents. All searches will be constrained to documents emitted by the index functions.

Here's an complete example of a design document with couchdb-lucene features:

{
    "_id":"lucene",
    "views": {
        "normal_couch_view": {
            "map": "function(){}"
        }
    },
    "fulltext": {
        "by_subject": {
            "defaults": { "store":"yes" },
            "index":"function(doc) { var ret=new Document(); ret.add(doc.subject); return ret }"
        },
        "by_content": {
            "defaults": { "store":"no" },
            "index":"function(doc) { var ret=new Document(); ret.add(doc.content); return ret }"
        }
    }
}

Here are some example URL's for the given design document;

https://localhost:5984/database/_fti/lucene/by_subject?q=hello
https://localhost:5984/database/_fti/lucene/by_content?q=hello

A fulltext object contains multiple index view declarations. An index view consists of;

The Defaults Object

The following indexing options can be defaulted;

The Analyzer Option

Lucene has numerous ways of converting free-form text into tokens, these classes are called Analyzer's. By default, the StandardAnalyzer is used which lower-cases all text, drops common English words ("the", "and", and so on), among other things. This processing might not always suit you, so you can choose from several others by setting the "analyzer" field to one of the following values;

• brazilian
• chinese
• cjk
• czech
• dutch
• english
• french
• german
• keyword
• porter
• russian
• simple
• standard
• thai

Note: You must also supply analyzer=<analyzer_name> as a query parameter to ensure that queries are processed correctly.

The Document class

You may construct a new Document instance with;

var doc = new Document();

Data may be added to this document with the add method which takes an optional second object argument that can override any of the above default values.

The data is usually interpreted as a String but couchdb-lucene provides special handling if a Javascript Date object is passed. Specifically, the date is indexed as a numeric value, which allows correct sorting, and stored (if requested) in ISO 8601 format (with a timezone marker).

// Add with all the defaults.
doc.add("value");
// Add a subject field.
doc.add("this is the subject line.", {"field":"subject"});
// Add but ensure it's stored.
doc.add("value", {"store":"yes"});
// Add but don't analyze.
doc.add("don't analyze me", {"index":"not_analyzed"});
// Extract text from the named attachment and index it (but not store it).
doc.attachment("attachment name", {"field":"attachments"});

Example Transforms

Index Everything

function(doc) {
    var ret = new Document();
    function idx(obj) {
    for (var key in obj) {
        switch (typeof obj[key]) {
        case 'object':
        idx(obj[key]);
        break;
        case 'function':
        break;
        default:
        ret.add(obj[key]);
        break;
        }
    }
    };
    idx(doc);
    if (doc._attachments) {
    for (var i in doc._attachments) {
        ret.attachment("attachment", i);
    }
    }
    
    return ret;
}

Index Nothing

function(doc) {
  return null;
}

Index Select Fields

function(doc) {
  var result = new Document();
  result.add(doc.subject, {"field":"subject", "store":"yes"});
  result.add(doc.content, {"field":"subject"});
  result.add({"field":"indexed_at"});
  return result;
}

Index Attachments

function(doc) {
  var result = new Document();
  for(var a in doc._attachments) {
    result.add_attachment(a, {"field":"attachment"});
  }
  return result;
}

A More Complex Example

function(doc) {
    var mk = function(name, value, group) {
        var ret = new Document();
        ret.add(value, {"field": group, "store":"yes"});
        ret.add(group, {"field":"group", "store":"yes"});
        return ret;
    };
    var ret = [];
    if(doc.type != "reference") return null;
    for(var g in doc.groups) {
        ret.add(mk("library", doc.groups[g].library, g));
        ret.add(mk("method", doc.groups[g].method, g));
        ret.add(mk("target", doc.groups[g].target, g));
    }
    return ret;
}

Attachment Indexing

Couchdb-lucene uses Apache Tika to index attachments of the following types, assuming the correct content_type is set in couchdb;

Supported Formats

• Excel spreadsheets (application/vnd.ms-excel)
• HTML (text/html)
• Images (image/*)
• Java class files
• Java jar archives
• MP3 (audio/mp3)
• OpenDocument (application/vnd.oasis.opendocument.*)
• Outlook (application/vnd.ms-outlook)
• PDF (application/pdf)
• Plain text (text/plain)
• Powerpoint presentations (application/vnd.ms-powerpoint)
• RTF (application/rtf)
• Visio (application/vnd.visio)
• Word documents (application/msword)
• XML (application/xml)

Searching with couchdb-lucene

You can perform all types of queries using Lucene's default query syntax. The _body field is searched by default which will include the extracted text from all attachments. The following parameters can be passed for more sophisticated searches;

All parameters except 'q' are optional.

Special Fields

Dublin Core

All Dublin Core attributes are indexed and stored if detected in the attachment. Descriptions of the fields come from the Tika javadocs.

Examples

https://localhost:5984/dbname/_fti/design_doc/view_name?q=field_name:value
https://localhost:5984/dbname/_fti/design_doc/view_name?q=field_name:value&sort;=other_field
https://localhost:5984/dbname/_fti/design_doc/view_name?debug=true&sort;=billing_size&q;=body:document AND customer:[A TO C]

Search Results Format

The search result contains a number of fields at the top level, in addition to your search results.

The search results array

The search results arrays consists of zero, one or more objects with the following fields;

Here's an example of a JSON response without sorting;

{
  "q": "+content:enron",
  "skip": 0,
  "limit": 2,
  "total_rows": 176852,
  "search_duration": 518,
  "fetch_duration": 4,
  "rows":   [
        {
      "id": "hain-m-all_documents-257.",
      "score": 1.601625680923462
    },
        {
      "id": "hain-m-notes_inbox-257.",
      "score": 1.601625680923462
    }
  ]
}

And the same with sorting;

{
  "q": "+content:enron",
  "skip": 0,
  "limit": 3,
  "total_rows": 176852,
  "search_duration": 660,
  "fetch_duration": 4,
  "sort_order":   [
        {
      "field": "source",
      "reverse": false,
      "type": "string"
    },
        {
      "reverse": false,
      "type": "doc"
    }
  ],
  "rows":   [
        {
      "id": "shankman-j-inbox-105.",
      "score": 0.6131107211112976,
      "sort_order":       [
        "enron",
        6
      ]
    },
        {
      "id": "shankman-j-inbox-8.",
      "score": 0.7492915391921997,
      "sort_order":       [
        "enron",
        7
      ]
    },
        {
      "id": "shankman-j-inbox-30.",
      "score": 0.507369875907898,
      "sort_order":       [
        "enron",
        8
      ]
    }
  ]
}

Content-Type of response

The Content-Type of the response is negotiated via the Accept request header like CouchDB itself. If the Accept header includes "application/json" then that is also the Content-Type of the response. If not, "text/plain;charset=utf-8" is used.

Fetching information about the index

Calling couchdb-lucene without arguments returns a JSON object with information about the whole index.

https://127.0.0.1:5984/enron/_fti

returns;

{"doc_count":517350,"doc_del_count":1,"disk_size":318543045}

Working With The Source

To develop "live", type "mvn dependency:unpack-dependencies" and change the external line to something like this;

fti=/usr/bin/java -server -cp /path/to/couchdb-lucene/target/classes:\
/path/to/couchdb-lucene/target/dependency com.github.rnewson.couchdb.lucene.Main

You will need to restart CouchDB if you change couchdb-lucene source code but this is very fast.

Configuration

couchdb-lucene respects several system properties;

You can override these properties like this;

fti=/usr/bin/java -Dcouchdb.lucene.dir=/tmp \
-cp /home/rnewson/Source/couchdb-lucene/target/classes:\
/home/rnewson/Source/couchdb-lucene/target/dependency\
com.github.rnewson.couchdb.lucene.Main

Basic Authentication

If you put couchdb behind an authenticating proxy you can still configure couchdb-lucene to pull from it by specifying additional system properties. Currently only Basic authentication is supported.

IPv6

The default for couchdb.url is problematic on an IPv6 system. Specify -Dcouchdb.url=https://[::1]:5984 to resolve it.