diff --git a/app/controllers/app.js b/app/controllers/app.js
index 5db65bf7..3eacda75 100755
--- a/app/controllers/app.js
+++ b/app/controllers/app.js
@@ -35,7 +35,7 @@ var express = require('express')
     , ApiKeyAuth  = require(global.settings.app_root + '/app/models/apikey_auth')
     , _           = require('underscore')
     , LRU         = require('lru-cache')
-    , formats = require(global.settings.app_root + '/app/models/formats')
+    , formats     = require(global.settings.app_root + '/app/models/formats')
     ;
 
 var tableCache = LRU({
@@ -45,9 +45,6 @@ var tableCache = LRU({
   maxAge: global.settings.tableCacheMaxAge || 1000*60*10
 });
 
-// Keeps track of what's waiting baking for export
-var bakingExports = {};
-
 app.use(express.bodyParser());
 app.enable('jsonp callback');
 
@@ -139,9 +136,6 @@ function handleQuery(req, res) {
           skipfields = [];
         }
 
-        // setup step run
-        var start = new Date().getTime();
-
         if ( -1 === supportedFormats.indexOf(format) )
           throw new Error("Invalid format: " + format);
 
@@ -155,11 +149,13 @@ function handleQuery(req, res) {
 
         var authenticated;
 
+        var formatter;
+
         // 1. Get database from redis via the username stored in the host header subdomain
         // 2. Run the request through OAuth to get R/W user id if signed
         // 3. Get the list of tables affected by the query
-        // 4. Run query with r/w or public user
-        // 5. package results and send back
+        // 4. Setup headers
+        // 5. Send formatted results back
         Step(
             function getDatabaseName() {
                 if (_.isNull(database)) {
@@ -205,7 +201,7 @@ function handleQuery(req, res) {
                    pg.query("SELECT CDB_QueryTables($quotesql$" + sql + "$quotesql$)", this);
                 }
             },
-            function queryResult(err, result){
+            function setHeaders(err, result){
                 if (err) throw err;
 
                 // store explain result in local Cache
@@ -239,28 +235,15 @@ function handleQuery(req, res) {
                 }
 
 
-                var f = formats[format]
-                if(f && !f.is_file) {
-                  sql = formats[format].getQuery(sql, {
-                    gn: gn,
-                    dp: dp,
-                    skipfields: skipfields
-                  })
-                } else {
-                  // These format are implemented via OGR2OGR, so we don't
-                  // need to run a query ourselves
-                  return null;
-                }
+                if ( ! formats.hasOwnProperty(format) ) throw new Error("Unknown format " + format);
+                var fClass = formats[format]
+                formatter = new fClass();
 
-                pg.query(window_sql(sql,limit,offset), this);
-            },
-            function setHeaders(err, result){
-                if (err) throw err;
 
                 // configure headers for given format
                 var use_inline = !requestedFormat && !requestedFilename;
                 res.header("Content-Disposition", getContentDisposition(format, filename, use_inline));
-                res.header("Content-Type", getContentType(format));
+                res.header("Content-Type", formatter.getContentType());
 
                 // allow cross site post
                 setCrossDomain(res);
@@ -277,105 +260,29 @@ function handleQuery(req, res) {
                   res.header('Cache-Control', 'no-cache,max-age='+ttl+',must-revalidate,public');
                 }
 
-
                 return result;
             },
-            function packageResults(err, result){
+            function generateFormat(err, result){
                 if (err) throw err;
 
-                if ( result && skipfields.length ){
-                  for ( var i=0; i<result.rows.length; ++i ) {
-                    for ( var j=0; j<skipfields.length; ++j ) {
-                      delete result.rows[i][skipfields[j]];
-                    }
-                  }
+                // TODO: drop this, fix UI!
+                sql = window_sql(sql,limit,offset);
+
+                var opts = {
+                  sink: res,
+                  gn: gn,
+                  dp: dp,
+                  skipfields: skipfields,
+                  database: database,
+                  user_id: user_id,
+                  sql: sql,
+                  filename: filename
                 }
 
-                var end = new Date().getTime();
-                var total_time = (end - start)/1000;
-
-                var f = formats[format];
-                if(!f.is_file) {
-                  f.transform(result, {
-                    gn: gn,
-                    dp: dp,
-                    skipfields: skipfields,
-                    total_time: total_time,
-                    database: database,
-                    user_id: user_id,
-                    sql: sql,
-                    filename: filename
-                  }, this)
-                  return;
-                } else {
-                  var opts = {
-                    gn: gn,
-                    dp: dp,
-                    skipfields: skipfields,
-                    database: database,
-                    user_id: user_id,
-                    sql: sql,
-                    filename: filename
-                  }
-                  var next = this;
-                  var reqKey = f.getKey(opts);
-                  var qElem = new ExportRequest(res, this);
-                  var baking = bakingExports[reqKey];
-                  if ( baking ) {
-                    baking.req.push( qElem );
-                  } else {
-                    baking = bakingExports[reqKey] = { req: [ qElem ] };
-                    f.generate(opts, function(err, dumpfile) {
-                      if(err) {
-                        next(err);
-                        return;
-                      }
-                      Step (
-                        function sendResults(err) {
-                          var nextPipe = function(finish) {
-                            var r = baking.req.shift();
-                            if ( ! r ) { finish(null); return; }
-                            r.sendFile(err, dumpfile, function() {
-                              nextPipe(finish);
-                            });
-                          }
-
-                          if ( ! err ) nextPipe(this);
-                          else {
-                            _.each(baking.req, function(r) {
-                              r.cb(err);
-                            });
-                            return true;
-                          }
-                        },
-                        function cleanup(err) {
-                          delete bakingExports[reqKey];
-
-                          // unlink dump file (sync to avoid race condition)
-                          console.log("removing", dumpfile);
-                          try { fs.unlinkSync(dumpfile); }
-                          catch (e) {
-                            if ( e.code != 'ENOENT' ) {
-                              console.log("Could not unlink dumpfile " + dumpfile + ": " + e);
-                            }
-                          }
-                        }
-                      );
-                    })
-                  }
-                  return;
-                }
-
-                throw new Error("Unexpected format in packageResults: " + format);
+                formatter.sendResponse(opts, this);
             },
-            function sendResults(err, out){
-                if (err) throw err;
-
-                // return to browser
-                if ( out ) res.send(out);
-            },
-            function errorHandle(err, result){
-                handleException(err, res);
+            function errorHandle(err){
+                if ( err ) handleException(err, res);
             }
         );
     } catch (err) {
@@ -391,44 +298,8 @@ function handleCacheStatus(req, res){
     res.send({explain: {pid: process.pid, hits: totalExplainHits, keys : totalExplainKeys }});
 }
 
-function ExportRequest(ostream, callback) {
-  this.cb = callback;
-  this.ostream = ostream;
-  this.istream = null;
-  this.canceled = false;
-
-  var that = this;
-
-  this.ostream.on('close', function() {
-    //console.log("Request close event, qElem.stream is " + qElem.stream);
-    that.canceled = true;
-    if ( that.istream ) {
-      that.istream.destroy();
-    }
-  });
-}
-
-ExportRequest.prototype.sendFile = function (err, filename, callback) {
-  var that = this;
-  if ( ! this.canceled ) {
-    //console.log("Creating readable stream out of dumpfile");
-    this.istream = fs.createReadStream(filename)
-    .on('open', function(fd) {
-      that.istream.pipe(that.ostream);
-      callback();
-    })
-    .on('error', function(e) {
-      console.log("Can't send response: " + e);
-      that.ostream.end(); 
-      callback();
-    });
-  } else {
-    //console.log("Response was canceled, not streaming the file");
-    callback();
-  }
-  this.cb();
-}
 
+// TODO: delegate to formats
 function getContentDisposition(format, filename, inline) {
     var ext = 'json';
     if (format === 'geojson'){
@@ -453,13 +324,6 @@ function getContentDisposition(format, filename, inline) {
     return ( inline ? 'inline' : 'attachment' ) +'; filename=' + filename + '.' + ext + '; modification-date="' + time + '";';
 }
 
-function getContentType(format){
-    var type = "application/json; charset=utf-8";
-    var f = formats[format]
-    type = f.getContentType();
-    return type;
-}
-
 function setCrossDomain(res){
     res.header("Access-Control-Allow-Origin", "*");
     res.header("Access-Control-Allow-Headers", "X-Requested-With, X-Prototype-Version, X-CSRF-Token");
diff --git a/app/models/formats/README b/app/models/formats/README
new file mode 100644
index 00000000..9e6b6443
--- /dev/null
+++ b/app/models/formats/README
@@ -0,0 +1,18 @@
+Format classes are required to expose a constructor with no arguments
+and a sendResponse(opts,callback) method.
+
+The ``opts`` parameter contains:
+
+ sink        Output stream to send the reponse to
+ sql         SQL query requested by the user
+ skipfields  Comma separate list of fields to skip from output
+             really only needed with "SELECT *" queries
+ gn          Name of the geometry column (for formats requiring one)
+ dp          Number of decimal points of precision for geometries (if used)
+ database    Name of the database to connect to
+ user_id     Identifier of the user
+ filename    Name to use for attachment disposition
+ 
+The ``callback`` parameter is a function that is invoked when the
+format object finished with sending the result to the sink.
+If an error occurs the callback is invoked with an Error argument.
diff --git a/app/models/formats/csv.js b/app/models/formats/csv.js
index 96a8b471..f0a4a7d7 100644
--- a/app/models/formats/csv.js
+++ b/app/models/formats/csv.js
@@ -1,59 +1,17 @@
+var ogr         = require('./ogr');
 
+function csv() {}
 
-var shp = require('./shp');
-var toOGR = shp.toOGR;
-var generateMD5 = shp.generateMD5;
+csv.prototype = new ogr('csv');
 
-function csv() {
-}
+var p = csv.prototype;
 
-csv.prototype = {
+p._contentType = "text/csv; charset=utf-8; header=present";
+p._fileExtension = "csv";
 
-  id: "csv",
-
-  is_file: true,
-
-  getQuery: function(sql, options) {
-    return null; // dont execute the query
-  },
-
-  getContentType: function(){
-    return "text/csv; charset=utf-8; header=present";
-  },
-
-  getFileExtension: function() {
-    return "csv"
-  },
-
-  transform: function(result, options, callback) {
-    throw "should not be called for file formats"
-  },
-
-  getKey: function(options) {
-    return [this.id,
-        options.dbname,
-        options.user_id,
-        options.gn,
-        generateMD5(options.sql)].concat(options.skipfields).join(':');
-  },
-
-  generate: function(options, callback) {
+p.generate = function(options, callback) {
     var o = options;
-    toOGR_SingleFile(o.database, o.user_id, o.gn, o.sql, o.skipfields, 'CSV', 'csv', callback);
-  }
-
+    this.toOGR_SingleFile(o.database, o.user_id, o.gn, o.sql, o.skipfields, 'CSV', 'csv', callback);
 };
 
-function toOGR_SingleFile(dbname, user_id, gcol, sql, skipfields, fmt, ext, callback) {
-  var tmpdir = global.settings.tmpDir || '/tmp';
-  var reqKey = [ fmt, dbname, user_id, gcol, generateMD5(sql) ].concat(skipfields).join(':');
-  var outdirpath = tmpdir + '/sqlapi-' + reqKey;
-  var dumpfile = outdirpath + ':cartodb-query.' + ext;
-
-  // TODO: following tests:
-  //  - fetch query with no "the_geom" column
-  toOGR(dbname, user_id, gcol, sql, skipfields, fmt, dumpfile, callback);
-}
-
-module.exports = new csv();
-module.exports.toOGR_SingleFile = toOGR_SingleFile;
+module.exports = csv;
diff --git a/app/models/formats/geojson.js b/app/models/formats/geojson.js
index dac08c96..f1514f7b 100644
--- a/app/models/formats/geojson.js
+++ b/app/models/formats/geojson.js
@@ -1,31 +1,23 @@
 
 var _ = require('underscore')
+var pg  = require('./pg');
 
-function geojson() {
-}
+function geojson() {}
 
-geojson.prototype = {
+geojson.prototype = new pg('geojson');
 
-  id: "geojson",
+var p = geojson.prototype;
 
-  getQuery: function(sql, options) {
+p._contentType = "application/json; charset=utf-8";
+
+p.getQuery = function(sql, options) {
     var gn = options.gn;
     var dp = options.dp;
     return 'SELECT *, ST_AsGeoJSON(' + gn + ',' + dp + ') as the_geom FROM (' + sql + ') as foo';
-  },
-
-  getContentType: function(){
-    return "application/json; charset=utf-8";
-  },
-
-  getFileExtension: function() {
-    return this.id;
-  },
-
-  transform: function(result, options, callback) {
-    _toGeoJSON(result, options.gn, callback);
-  }
+};
 
+p.transform = function(result, options, callback) {
+  _toGeoJSON(result, options.gn, callback);
 };
 
 function _toGeoJSON(data, gn, callback){
@@ -55,5 +47,5 @@ function _toGeoJSON(data, gn, callback){
   }
 }
 
-module.exports = new geojson();
+module.exports = geojson;
 module.exports.toGeoJSON = _toGeoJSON
diff --git a/app/models/formats/index.js b/app/models/formats/index.js
index 16dc64d9..120695e5 100644
--- a/app/models/formats/index.js
+++ b/app/models/formats/index.js
@@ -8,9 +8,9 @@ var path = require('path');
 var folder = __dirname + "/"
 //"./app/models/formats/"
 require("fs").readdirSync(folder).forEach(function(file) {
-  if (path.extname(file) === '.js' && file !== 'index.js') {
+  if (path.extname(file) === '.js' && file !== 'index.js' && file !== 'ogr.js' && file !== 'pg.js' ) {
     var format = require(folder + file);
-    formats[format.id] = format;
+    formats[format.prototype.id] = format;
   }
 });
 
diff --git a/app/models/formats/json.js b/app/models/formats/json.js
index 68e3c74c..9915ed9e 100644
--- a/app/models/formats/json.js
+++ b/app/models/formats/json.js
@@ -1,32 +1,20 @@
+var pg  = require('./pg');
 
-function json() {
-}
+function json() {}
 
-json.prototype = {
+json.prototype = new pg('json');
 
-  id: "json",
+var p = json.prototype;
 
-  getQuery: function(sql, options) {
-    return sql;
-  },
+p._contentType = "application/json; charset=utf-8";
 
-  getContentType: function(){
-    return "application/json; charset=utf-8";
-  },
-
-  getFileExtension: function() {
-    return this.id;
-  },
-
-  transform: function(result, options, callback) {
-    var j = {
-      time: options.total_time,
-      total_rows: result.rowCount,
-      rows: result.rows
-    }
-    callback(null, j);
+p.transform = function(result, options, callback) {
+  var j = {
+    time: options.total_time,
+    total_rows: result.rowCount,
+    rows: result.rows
   }
-
+  callback(null, j);
 };
 
-module.exports = new json();
+module.exports = json;
diff --git a/app/models/formats/kml.js b/app/models/formats/kml.js
index 9831a9fb..7f2527fa 100644
--- a/app/models/formats/kml.js
+++ b/app/models/formats/kml.js
@@ -1,44 +1,17 @@
-var toOGR_SingleFile = require('./csv').toOGR_SingleFile
-var generateMD5 = require('./shp').generateMD5;
+var ogr         = require('./ogr');
 
-function kml() {
-}
+function kml() {}
 
-kml.prototype = {
+kml.prototype = new ogr('kml');
 
-  id: "kml",
+var p = kml.prototype;
 
-  is_file: true,
+p._contentType = "application/kml; charset=utf-8";
+p._fileExtension = "kml";
 
-  getQuery: function(sql, options) {
-    return null; // dont execute the query
-  },
-
-  getContentType: function(){
-    return "application/kml; charset=utf-8";
-  },
-
-  getFileExtension: function() {
-    return "kml"
-  },
-
-  transform: function(result, options, callback) {
-    throw "should not be called for file formats"
-  },
-
-  getKey: function(options) {
-    return [this.id,
-        options.dbname,
-        options.user_id,
-        options.gn,
-        generateMD5(options.sql)].concat(options.skipfields).join(':');
-  },
-
-  generate: function(options, callback) {
+p.generate = function(options, callback) {
     var o = options;
-    toOGR_SingleFile(o.database, o.user_id, o.gn, o.sql, o.skipfields, 'KML', 'kml', callback);
-  }
-
+    this.toOGR_SingleFile(o.database, o.user_id, o.gn, o.sql, o.skipfields, 'KML', 'kml', callback);
 };
 
-module.exports = new kml();
+module.exports = kml;
diff --git a/app/models/formats/ogr.js b/app/models/formats/ogr.js
new file mode 100644
index 00000000..ac58e723
--- /dev/null
+++ b/app/models/formats/ogr.js
@@ -0,0 +1,263 @@
+
+var crypto      = require('crypto')
+var Step        = require('step')
+var fs          = require('fs')
+var _           = require('underscore')
+var PSQL        = require(global.settings.app_root + '/app/models/psql')
+var spawn       = require('child_process').spawn
+
+// Keeps track of what's waiting baking for export
+var bakingExports = {};
+
+// Return database username from user_id
+// NOTE: a "null" user_id is a request to use the public user
+function userid_to_dbuser(user_id) {
+  if ( _.isString(user_id) )
+      return _.template(global.settings.db_user, {user_id: user_id});
+  return "publicuser" // FIXME: make configurable
+};
+
+
+
+function ogr(id) {
+  this.id = id;
+}
+
+ogr.prototype = {
+
+  id: "ogr",
+
+  is_file: true,
+
+  getQuery: function(sql, options) {
+    return null; // dont execute the query
+  },
+
+  transform: function(result, options, callback) {
+    throw "should not be called for file formats"
+  },
+
+  getContentType: function(){ return this._contentType; },
+
+  getFileExtension: function(){ return this._fileExtension; },
+
+  getKey: function(options) {
+    return [this.id,
+        options.dbname,
+        options.user_id,
+        options.gn,
+        this.generateMD5(options.sql)].concat(options.skipfields).join(':');
+  },
+
+  generateMD5: function (data){
+    var hash = crypto.createHash('md5');
+    hash.update(data);
+    return hash.digest('hex');
+  }
+
+};
+
+// Internal function usable by all OGR-driven outputs
+ogr.prototype.toOGR = function(dbname, user_id, gcol, sql, skipfields, out_format, out_filename, callback) {
+  var ogr2ogr = 'ogr2ogr'; // FIXME: make configurable
+  var dbhost = global.settings.db_host;
+  var dbport = global.settings.db_port;
+  var dbuser = userid_to_dbuser(user_id);
+  var dbpass = ''; // turn into a parameter..
+
+  var columns = [];
+
+  // Drop ending semicolon (ogr doens't like it)
+  sql = sql.replace(/;\s*$/, ''); 
+
+  Step (
+
+    function fetchColumns() {
+      var colsql = 'SELECT * FROM (' + sql + ') as _cartodbsqlapi LIMIT 1';
+      var pg = new PSQL(user_id, dbname, 1, 0);
+      pg.query(colsql, this);
+    },
+    function spawnDumper(err, result) {
+      if (err) throw err;
+
+      //if ( ! result.rows.length ) throw new Error("Query returns no rows");
+
+      // Skip system columns
+      if ( result.rows.length ) {
+        for (var k in result.rows[0]) {
+          if ( skipfields.indexOf(k) != -1 ) continue;
+          if ( out_format != 'CSV' && k == "the_geom_webmercator" ) continue; // TODO: drop ?
+          if ( out_format == 'CSV' ) columns.push('"' + k + '"::text');
+          else columns.push('"' + k + '"');
+        }
+      } else columns.push('*');
+      //console.log(columns.join(','));
+
+      var next = this;
+
+      sql = 'SELECT ' + columns.join(',')
+          + ' FROM (' + sql + ') as _cartodbsqlapi';
+
+      var child = spawn(ogr2ogr, [
+        '-f', out_format,
+        '-lco', 'ENCODING=UTF-8',
+        '-lco', 'LINEFORMAT=CRLF',
+        out_filename,
+        "PG:host=" + dbhost
+         + " user=" + dbuser
+         + " dbname=" + dbname
+         + " password=" + dbpass
+         + " tables=fake" // trick to skip query to geometry_columns
+         + "",
+        '-sql', sql
+      ]);
+
+/*
+console.log(['ogr2ogr',
+        '-f', '"'+out_format+'"',
+        out_filename,
+        "'PG:host=" + dbhost
+         + " user=" + dbuser
+         + " dbname=" + dbname
+         + " password=" + dbpass
+         + " tables=fake" // trick to skip query to geometry_columns
+         + "'",
+        "-sql '", sql, "'"].join(' '));
+*/
+
+      var stdout = '';
+      child.stdout.on('data', function(data) {
+        stdout += data;
+        //console.log('stdout: ' + data);
+      });
+
+      var stderr;
+      var logErrPat = new RegExp(/^ERROR/);
+      child.stderr.on('data', function(data) {
+        data = data.toString(); // know of a faster way ?
+        // Store only the first ERROR line
+        if ( ! stderr && data.match(logErrPat) ) stderr = data;
+        console.log('ogr2ogr stderr: ' + data);
+      });
+
+      child.on('exit', function(code) {
+        if ( code ) {
+          var emsg = stderr.split('\n')[0];
+          // TODO: add more info about this error ?
+          //if ( RegExp(/attempt to write non-.*geometry.*to.*type shapefile/i).exec(emsg) )
+          next(new Error(emsg));
+        } else {
+          next(null);
+        }
+      });
+    },
+    function finish(err) {
+      callback(err, out_filename);
+    }
+  );
+};
+
+ogr.prototype.toOGR_SingleFile = function(dbname, user_id, gcol, sql, skipfields, fmt, ext, callback) {
+  var tmpdir = global.settings.tmpDir || '/tmp';
+  var reqKey = [ fmt, dbname, user_id, gcol, this.generateMD5(sql) ].concat(skipfields).join(':');
+  var outdirpath = tmpdir + '/sqlapi-' + reqKey;
+  var dumpfile = outdirpath + ':cartodb-query.' + ext;
+
+  // TODO: following tests:
+  //  - fetch query with no "the_geom" column
+  this.toOGR(dbname, user_id, gcol, sql, skipfields, fmt, dumpfile, callback);
+};
+
+ogr.prototype.sendResponse = function(opts, callback) {
+  var next = callback;
+  var reqKey = this.getKey(opts);
+  var qElem = new ExportRequest(opts.sink, callback);
+  var baking = bakingExports[reqKey];
+  if ( baking ) {
+    baking.req.push( qElem );
+  } else {
+    baking = bakingExports[reqKey] = { req: [ qElem ] };
+    this.generate(opts, function(err, dumpfile) {
+      if(err) {
+        next(err);
+        return;
+      }
+      Step (
+        function sendResults(err) {
+          var nextPipe = function(finish) {
+            var r = baking.req.shift();
+            if ( ! r ) { finish(null); return; }
+            r.sendFile(err, dumpfile, function() {
+              nextPipe(finish);
+            });
+          }
+
+          if ( ! err ) nextPipe(this);
+          else {
+            _.each(baking.req, function(r) {
+              r.cb(err);
+            });
+            return true;
+          }
+        },
+        function cleanup(err) {
+          delete bakingExports[reqKey];
+
+          // unlink dump file (sync to avoid race condition)
+          console.log("removing", dumpfile);
+          try { fs.unlinkSync(dumpfile); }
+          catch (e) {
+            if ( e.code != 'ENOENT' ) {
+              console.log("Could not unlink dumpfile " + dumpfile + ": " + e);
+            }
+          }
+        }
+      );
+    })
+  }
+  return;
+};
+
+// TODO: put in an ExportRequest.js ----- {
+
+function ExportRequest(ostream, callback) {
+  this.cb = callback;
+  this.ostream = ostream;
+  this.istream = null;
+  this.canceled = false;
+
+  var that = this;
+
+  this.ostream.on('close', function() {
+    //console.log("Request close event, qElem.stream is " + qElem.stream);
+    that.canceled = true;
+    if ( that.istream ) {
+      that.istream.destroy();
+    }
+  });
+}
+
+ExportRequest.prototype.sendFile = function (err, filename, callback) {
+  var that = this;
+  if ( ! this.canceled ) {
+    //console.log("Creating readable stream out of dumpfile");
+    this.istream = fs.createReadStream(filename)
+    .on('open', function(fd) {
+      that.istream.pipe(that.ostream);
+      callback();
+    })
+    .on('error', function(e) {
+      console.log("Can't send response: " + e);
+      that.ostream.end(); 
+      callback();
+    });
+  } else {
+    //console.log("Response was canceled, not streaming the file");
+    callback();
+  }
+  this.cb();
+}
+
+//------ }
+
+module.exports = ogr;
diff --git a/app/models/formats/pg.js b/app/models/formats/pg.js
new file mode 100644
index 00000000..f0a0868c
--- /dev/null
+++ b/app/models/formats/pg.js
@@ -0,0 +1,67 @@
+var Step        = require('step')
+var PSQL = require(global.settings.app_root + '/app/models/psql')
+
+function pg(id) { this.id = id; }
+
+pg.prototype = {
+
+  getQuery: function(sql, options) {
+    return sql;
+  },
+
+  getContentType: function(){
+    return this._contentType;
+  },
+
+  getFileExtension: function() {
+    return this.id;
+  },
+
+};
+
+pg.prototype.sendResponse = function(opts, callback) {
+  var sql = this.getQuery(opts.sql, {
+    gn: opts.gn,
+    dp: opts.dp,
+    skipfields: opts.skipfields
+  });
+
+  var that = this;
+
+  var start = Date.now();
+
+  Step (
+    function sendQuery() {
+      var client = new PSQL(opts.user_id, opts.database);
+      client.query(sql, this);
+    },
+    function packageResults(err, result) {
+      if (err) throw err;
+
+      if ( result && opts.skipfields.length ){
+        for ( var i=0; i<result.rows.length; ++i ) {
+          for ( var j=0; j<opts.skipfields.length; ++j ) {
+            delete result.rows[i][opts.skipfields[j]];
+          }
+        }
+      }
+
+      var end = Date.now();
+      opts.total_time = (end - start)/1000;
+
+      that.transform(result, opts, this);
+    },
+    function sendResults(err, out){
+
+        if (err) throw err;
+
+        // return to browser
+        if ( out ) opts.sink.send(out);
+    },
+    function errorHandle(err){
+        callback(err);
+    }
+  );
+};
+
+module.exports = pg;
diff --git a/app/models/formats/shp.js b/app/models/formats/shp.js
index 99bb1f7e..7e48d82a 100644
--- a/app/models/formats/shp.js
+++ b/app/models/formats/shp.js
@@ -1,173 +1,30 @@
 
-var crypto      = require('crypto')
-var Step        = require('step')
-var fs          = require('fs')
-var _           = require('underscore')
-var PSQL        = require(global.settings.app_root + '/app/models/psql')
-var spawn       = require('child_process').spawn
+var crypto      = require('crypto');
+var Step        = require('step');
+var fs          = require('fs');
+var spawn       = require('child_process').spawn;
+var ogr         = require('./ogr');
 
 function shp() {
 }
 
-shp.prototype = {
+shp.prototype = new ogr('shp');
 
-  id: "shp",
+var p = shp.prototype;
 
-  is_file: true,
-
-  getQuery: function(sql, options) {
-    return null; // dont execute the query
-  },
-
-  getContentType: function(){
-    return "application/zip; charset=utf-8";
-  },
-
-  getFileExtension: function() {
-    return "zip"
-  },
-
-  transform: function(result, options, callback) {
-    throw "should not be called for file formats"
-  },
-
-  getKey: function(options) {
-    return [this.id,
-        options.dbname,
-        options.user_id,
-        options.gn,
-        generateMD5(options.sql)].concat(options.skipfields).join(':');
-  },
-
-  generate: function(options, callback) {
-    var o = options;
-    toSHP(o.database, o.user_id, o.gn, o.sql, o.skipfields, o.filename, callback);
-  }
+p._contentType = "application/zip; charset=utf-8";
+p._fileExtension = "zip";
 
+p.generate = function(options, callback) {
+  var o = options;
+  this.toSHP(o.database, o.user_id, o.gn, o.sql, o.skipfields, o.filename, callback);
 };
 
-function generateMD5(data){
-    var hash = crypto.createHash('md5');
-    hash.update(data);
-    return hash.digest('hex');
-}
-
-
-
-// Return database username from user_id
-// NOTE: a "null" user_id is a request to use the public user
-function userid_to_dbuser(user_id) {
-  if ( _.isString(user_id) )
-      return _.template(global.settings.db_user, {user_id: user_id});
-  return "publicuser" // FIXME: make configurable
-};
-
-
-
-// Internal function usable by all OGR-driven outputs
-function toOGR(dbname, user_id, gcol, sql, skipfields, out_format, out_filename, callback) {
-  var ogr2ogr = 'ogr2ogr'; // FIXME: make configurable
-  var dbhost = global.settings.db_host;
-  var dbport = global.settings.db_port;
-  var dbuser = userid_to_dbuser(user_id);
-  var dbpass = ''; // turn into a parameter..
-
-  var columns = [];
-
-  // Drop ending semicolon (ogr doens't like it)
-  sql = sql.replace(/;\s*$/, ''); 
-
-  Step (
-
-    function fetchColumns() {
-      var colsql = 'SELECT * FROM (' + sql + ') as _cartodbsqlapi LIMIT 1';
-      var pg = new PSQL(user_id, dbname, 1, 0);
-      pg.query(colsql, this);
-    },
-    function spawnDumper(err, result) {
-      if (err) throw err;
-
-      //if ( ! result.rows.length ) throw new Error("Query returns no rows");
-
-      // Skip system columns
-      if ( result.rows.length ) {
-        for (var k in result.rows[0]) {
-          if ( skipfields.indexOf(k) != -1 ) continue;
-          if ( out_format != 'CSV' && k == "the_geom_webmercator" ) continue; // TODO: drop ?
-          if ( out_format == 'CSV' ) columns.push('"' + k + '"::text');
-          else columns.push('"' + k + '"');
-        }
-      } else columns.push('*');
-      //console.log(columns.join(','));
-
-      var next = this;
-
-      sql = 'SELECT ' + columns.join(',')
-          + ' FROM (' + sql + ') as _cartodbsqlapi';
-
-      var child = spawn(ogr2ogr, [
-        '-f', out_format,
-        '-lco', 'ENCODING=UTF-8',
-        '-lco', 'LINEFORMAT=CRLF',
-        out_filename,
-        "PG:host=" + dbhost
-         + " user=" + dbuser
-         + " dbname=" + dbname
-         + " password=" + dbpass
-         + " tables=fake" // trick to skip query to geometry_columns
-         + "",
-        '-sql', sql
-      ]);
-
-/*
-console.log(['ogr2ogr',
-        '-f', '"'+out_format+'"',
-        out_filename,
-        "'PG:host=" + dbhost
-         + " user=" + dbuser
-         + " dbname=" + dbname
-         + " password=" + dbpass
-         + " tables=fake" // trick to skip query to geometry_columns
-         + "'",
-        "-sql '", sql, "'"].join(' '));
-*/
-
-      var stdout = '';
-      child.stdout.on('data', function(data) {
-        stdout += data;
-        //console.log('stdout: ' + data);
-      });
-
-      var stderr;
-      var logErrPat = new RegExp(/^ERROR/);
-      child.stderr.on('data', function(data) {
-        data = data.toString(); // know of a faster way ?
-        // Store only the first ERROR line
-        if ( ! stderr && data.match(logErrPat) ) stderr = data;
-        console.log('ogr2ogr stderr: ' + data);
-      });
-
-      child.on('exit', function(code) {
-        if ( code ) {
-          var emsg = stderr.split('\n')[0];
-          // TODO: add more info about this error ?
-          //if ( RegExp(/attempt to write non-.*geometry.*to.*type shapefile/i).exec(emsg) )
-          next(new Error(emsg));
-        } else {
-          next(null);
-        }
-      });
-    },
-    function finish(err) {
-      callback(err, out_filename);
-    }
-  );
-}
-
-function toSHP(dbname, user_id, gcol, sql, skipfields, filename, callback) {
+p.toSHP = function (dbname, user_id, gcol, sql, skipfields, filename, callback) {
+  var fmtObj = this;
   var zip = 'zip'; // FIXME: make configurable
   var tmpdir = global.settings.tmpDir || '/tmp';
-  var reqKey = [ 'shp', dbname, user_id, gcol, generateMD5(sql) ].concat(skipfields).join(':');
+  var reqKey = [ 'shp', dbname, user_id, gcol, this.generateMD5(sql) ].concat(skipfields).join(':');
   var outdirpath = tmpdir + '/sqlapi-' + reqKey; 
   var zipfile = outdirpath + '.zip';
   var shapefile = outdirpath + '/' + filename + '.shp';
@@ -181,7 +38,7 @@ function toSHP(dbname, user_id, gcol, sql, skipfields, filename, callback) {
     },
     function spawnDumper(err) {
       if ( err ) throw err;
-      toOGR(dbname, user_id, gcol, sql, skipfields, 'ESRI Shapefile', shapefile, this);
+      fmtObj.toOGR(dbname, user_id, gcol, sql, skipfields, 'ESRI Shapefile', shapefile, this);
     },
     function doZip(err) {
       if ( err ) throw err;
@@ -237,10 +94,8 @@ function toSHP(dbname, user_id, gcol, sql, skipfields, filename, callback) {
       });
     }
   );
-}
+};
 
 
-module.exports = new shp();
-module.exports.toOGR = toOGR;
-module.exports.generateMD5 = generateMD5
+module.exports = shp;
 
diff --git a/app/models/formats/svg.js b/app/models/formats/svg.js
index d49a3caf..67ff03a6 100644
--- a/app/models/formats/svg.js
+++ b/app/models/formats/svg.js
@@ -1,54 +1,44 @@
-
+var pg  = require('./pg');
 var _ = require('underscore')
 
-function svg() {
-}
-
 var svg_width  = 1024.0;
 var svg_height = 768.0;
 var svg_ratio = svg_width/svg_height;
 
-svg.prototype = {
+function svg() {}
 
-  id: "svg",
+svg.prototype = new pg('svg');
 
+var p = svg.prototype;
 
-  getQuery: function(sql, options) {
-    var gn = options.gn;
-    var dp = options.dp;
-    return  'WITH source AS ( ' + sql + '), extent AS ( '
-          + ' SELECT ST_Extent(' + gn + ') AS e FROM source '
-          + '), extent_info AS ( SELECT e, '
-          + 'st_xmin(e) as ex0, st_ymax(e) as ey0, '
-          + 'st_xmax(e)-st_xmin(e) as ew, '
-          + 'st_ymax(e)-st_ymin(e) as eh FROM extent )'
-          + ', trans AS ( SELECT CASE WHEN '
-          + 'eh = 0 THEN ' + svg_width
-          + '/ COALESCE(NULLIF(ew,0),' + svg_width +') WHEN '
-          + svg_ratio + ' <= (ew / eh) THEN ('
-          + svg_width  + '/ew ) ELSE ('
-          + svg_height + '/eh ) END as s '
-          + ', ex0 as x0, ey0 as y0 FROM extent_info ) '
-          + 'SELECT st_TransScale(e, -x0, -y0, s, s)::box2d as '
-          + gn + '_box, ST_Dimension(' + gn + ') as ' + gn
-          + '_dimension, ST_AsSVG(ST_TransScale(' + gn + ', '
-          + '-x0, -y0, s, s), 0, ' + dp + ') as ' + gn
-          //+ ', ex0, ey0, ew, eh, s ' // DEBUG ONLY
-          + ' FROM trans, extent_info, source';
-  },
+p.getQuery = function(sql, options) {
+  var gn = options.gn;
+  var dp = options.dp;
+  return  'WITH source AS ( ' + sql + '), extent AS ( '
+        + ' SELECT ST_Extent(' + gn + ') AS e FROM source '
+        + '), extent_info AS ( SELECT e, '
+        + 'st_xmin(e) as ex0, st_ymax(e) as ey0, '
+        + 'st_xmax(e)-st_xmin(e) as ew, '
+        + 'st_ymax(e)-st_ymin(e) as eh FROM extent )'
+        + ', trans AS ( SELECT CASE WHEN '
+        + 'eh = 0 THEN ' + svg_width
+        + '/ COALESCE(NULLIF(ew,0),' + svg_width +') WHEN '
+        + svg_ratio + ' <= (ew / eh) THEN ('
+        + svg_width  + '/ew ) ELSE ('
+        + svg_height + '/eh ) END as s '
+        + ', ex0 as x0, ey0 as y0 FROM extent_info ) '
+        + 'SELECT st_TransScale(e, -x0, -y0, s, s)::box2d as '
+        + gn + '_box, ST_Dimension(' + gn + ') as ' + gn
+        + '_dimension, ST_AsSVG(ST_TransScale(' + gn + ', '
+        + '-x0, -y0, s, s), 0, ' + dp + ') as ' + gn
+        //+ ', ex0, ey0, ew, eh, s ' // DEBUG ONLY
+        + ' FROM trans, extent_info, source';
+};
 
-  getContentType: function(){
-    return "image/svg+xml; charset=utf-8";
-  },
-
-  getFileExtension: function() {
-    return this.id;
-  },
-
-  transform: function(result, options, callback) {
-    toSVG(result.rows, options.gn, callback);
-  }
+p._contentType = "image/svg+xml; charset=utf-8";
 
+p.transform = function(result, options, callback) {
+  toSVG(result.rows, options.gn, callback);
 };
 
 
@@ -147,4 +137,4 @@ function toSVG(rows, gn, callback) {
     callback(null, out.join("\n"));
 }
 
-module.exports = new svg();
+module.exports = svg;
diff --git a/app/models/formats/topojson.js b/app/models/formats/topojson.js
index 0d8af817..e5864af4 100644
--- a/app/models/formats/topojson.js
+++ b/app/models/formats/topojson.js
@@ -1,26 +1,23 @@
 
+var pg  = require('./pg');
 var _ = require('underscore')
 var geojson = require('./geojson');
 var TopoJSON = require('topojson');
 
-function topojson() {
-}
+function topojson() { }
 
-topojson.prototype = {};
+topojson.prototype = new pg('topojson');
 
-_.extend(topojson.prototype, geojson, {
-  id: "topojson",
+var p = topojson.prototype;
 
-  getQuery: function(sql, options) {
-    var sql = geojson.getQuery(sql, options);
-    return sql + ' where ' + options.gn + ' is not null';
-  },
+p.getQuery = function(sql, options) {
+  var sql = geojson.prototype.getQuery(sql, options);
+  return sql + ' where ' + options.gn + ' is not null';
+};
 
-  transform: function(result, options, callback) {
-    toTopoJSON(result, options.gn, options.skipfields, callback);
-  }
-
-})
+p.transform = function(result, options, callback) {
+  toTopoJSON(result, options.gn, options.skipfields, callback);
+};
 
 function toTopoJSON(data, gn, skipfields, callback){
   geojson.toGeoJSON(data, gn, function(err, geojson) {
@@ -47,4 +44,4 @@ function toTopoJSON(data, gn, skipfields, callback){
 }
 
 
-module.exports = new topojson();
+module.exports = topojson;