= FDO RFC 16 - FDO Provider for SQLite =

This page contains a request for comments document (RFC) for the FDO Open Source project.  
More FDO RFCs can be found on the [wiki:FDORfcs RFCs] page.

== Status == 
 
||RFC Template Version||(1.0)|| 
||Submission Date||2008-03-18||
||Last Modified||Traian Stanev 2008-03-18||
||Author||Traian Stanev||
||RFC Status||draft||
||Implementation Status||under development||
||Proposed Milestone||||
||Assigned PSC guide(s)||(when determined)||
||'''Voting History'''||(vote date)||
||+1||||
||+0||||
||-0||||
||-1||||
 
== Overview ==

This RFC proposes a new FDO provider for accessing (spatial) data stored in SQLite database files.

== Motivation ==

SQLite is an efficient and popular way to store data. Support for accessing SQLite databases via FDO would expand the range of data sources supported by FDO.

== Proposed Solution ==

The proposed SQLite provider will have the following features:

 * Data stored and consumed in native SQLite format, and therefore accessible to other SQLite-based applications;
 * Geometry will be serialized as BLOBs in FDO geometry format (FGF), WKB , or WKT 1.2 format. The type of geometry encoding will be specified in the geometry_columns table (see below) in a column called g_geometry_format. In addition, the provider may support point geometry with coordinates stored in non-geometric columns, via a connection string setting.
 * A non-persistent, spatial index usable for BBOX queries built on the fly and valid for the duration of the FDO connection;
 * Execution of arbitrary SQL commands;
 * Metadata about feature geometry and coordinate systems will be stored in OGC geometry_columns and spatial_ref_sys tables, according to Section 6.2.1 of the OGC Simple Feature spec, Part 2;
 * A tentative list of supported FDO commands : !DescribeSchema, Select, !SelectAggregates, Insert, Update, Delete, !GetSpatialContexts, arbitrary SQL, !ApplySchema, !CreateDataStore;

FDO features the provider will likely *not* support:

 * Feature class inheritance;
 * Geometry filters other than BBOX;
 * FDO Transactions -- but you can still manually execute BEGIN/COMMIT around other FDO commands;
 * Associations;
 * Constraints;
 * Any other exotic feature you can think of.


== Implications ==

This is a new provider, so there will be no issues with backwards compatibility.

== Test Plan ==

There will be a small test suite that tests often used functionality. Arbitrary SQL execution will not be tested extensively.

== Funding/Resources ==