DAV Searching and Locating
charter-ietf-dasl-01

The goal of this working group is to define and develop an extensible
DAV Searching and Locating protocol as an application of HTTP. The
working group will define protocol elements that enable server-executed
queries to locate resources based upon their property values and text
content as expressed by the DAV data model.

Problem Definition

WEBDAV and HTTP enable client-side searching by defining a simple set of
mechanisms (the PROPFIND and GET methods) to locate those resources
meeting client-defined criteria. These mechanisms can be inefficient, do
not adequately deal with some simple content-based queries, and do not
take advantage of the advanced querying and caching capabilities of
modern storage systems.

The DASL Protocol will enable a HTTP/1.1 compliant scheme for
server-side searching to address these limitations. The working group
will define the following for a server-side searching mechanism:

• How to express the search: the syntax and semantics of a query

• How to focus the query by identifying its scope

• How to discover the search capability of a resource.

• The syntax for the search results

Working Group Scope

A generalized search mechanism is a broad problem space. It encompasses
a variety of object models, typing schemes, and media. By focusing on a
subset of this space, the problem of locating resources based on
property values and text content, the working group will leverage much
of the existing work that has been done on querying under simple
property and resource models.

In-Scope items include:

• typing

• comparisons (greater than,greater than or equal to, less than,
  less than or equal to, !=, ==)

• internationalized content

• text content matching

• dealing with arbitrary XML values

Out-of-scope items include:

• definitions of well-known properties

• server-to-server communication protocols

• cross-language comparisons

• searching for non-text content (images, video, audio, etc.)

• client control of server administration (e.g. indexing)

Deliverables

The final output of this working group is expected to be two documents:

(1) A requirements document, that describes the high-level functional
requirements for DASL, including rationale. This will be an
Informational document.

(2) A protocol specification describing the additions to HTTP (new
methods, headers, request bodies, and response bodies) needed to
implement the DASL requirements. This will be a Standards Track
document.