diff --git a/trytond/ir/action.py b/trytond/ir/action.py
index 932deab8ac..76e19ab308 100644
--- a/trytond/ir/action.py
+++ b/trytond/ir/action.py
@@ -8,15 +8,13 @@ class Action(OSV):
     "Action"
     _name = 'ir.action'
     _description = __doc__
-    _columns = {
-        'name': fields.char('Name', required=True, size=64, translate=True),
-        'type': fields.char('Type', required=True, size=32, readonly=True),
-        'usage': fields.char('Usage', size=32),
-        'keywords': fields.one2many('ir.action.keyword', 'action',
-            'Keywords'),
-        'groups': fields.Many2Many('res.group', 'ir_action_group_rel',
-            'action_id', 'gid', 'Groups'),
-    }
+    name = fields.char('Name', required=True, size=64, translate=True)
+    type = fields.char('Type', required=True, size=32, readonly=True)
+    usage = fields.char('Usage', size=32)
+    keywords = fields.one2many('ir.action.keyword', 'action',
+            'Keywords')
+    groups = fields.Many2Many('res.group', 'ir_action_group_rel',
+            'action_id', 'gid', 'Groups')
     _defaults = {
         'usage': lambda *a: False,
     }
@@ -49,18 +47,16 @@ class ActionKeyword(OSV):
     "Action keyword"
     _name = 'ir.action.keyword'
     _description = __doc__
-    _columns = {
-        'keyword': fields.Selection([
+    keyword = fields.Selection([
             ('tree_open', 'Open tree'),
             ('tree_action', 'Action tree'),
             ('form_print', 'Print form'),
             ('form_action', 'Action form'),
             ('form_relate', 'Form relate'),
-            ], string='Keyword', required=True),
-        'model': fields.Reference('Model', selection='models_get', size=128),
-        'action': fields.many2one('ir.action', 'Action',
-            ondelete='CASCADE'),
-    }
+            ], string='Keyword', required=True)
+    model = fields.Reference('Model', selection='models_get', size=128)
+    action = fields.many2one('ir.action', 'Action',
+            ondelete='CASCADE')
 
     def __init__(self, pool):
         super(ActionKeyword, self).__init__(pool)
@@ -170,16 +166,14 @@ class ActionReport(OSV):
     _sequence = 'ir_action_id_seq'
     _description = __doc__
     _inherits = {'ir.action': 'action'}
-    _columns = {
-        'model': fields.Char('Model', size=64, required=True),
-        'report_name': fields.Char('Internal Name', size=64, required=True),
-        'report': fields.Char('Path', size=128),
-        'report_content_data': fields.Binary('Content'),
-        'report_content': fields.Function('report_content',
-            fnct_inv='report_content_inv', type='binary',
-            string='Content',),
-        'action': fields.Many2One('ir.action', 'Action', required=True),
-    }
+    model = fields.Char('Model', size=64, required=True)
+    report_name = fields.Char('Internal Name', size=64, required=True)
+    report = fields.Char('Path', size=128)
+    report_content_data = fields.Binary('Content')
+    report_content = fields.Function('get_report_content',
+        fnct_inv='report_content_inv', type='binary',
+        string='Content')
+    action = fields.Many2One('ir.action', 'Action', required=True)
     _defaults = {
         'type': lambda *a: 'ir.action.report',
         'report_content': lambda *a: False,
@@ -189,7 +183,7 @@ class ActionReport(OSV):
             'The internal name must be unique!'),
     ]
 
-    def report_content(self, cursor, user, ids, name, arg, context=None):
+    def get_report_content(self, cursor, user, ids, name, arg, context=None):
         res = {}
         for report in self.browse(cursor, user, ids, context=context):
             data = report[name + '_data']
@@ -224,24 +218,22 @@ class ActionActWindow(OSV):
     _sequence = 'ir_action_id_seq'
     _description = __doc__
     _inherits = {'ir.action': 'action'}
-    _columns = {
-        'domain': fields.Char('Domain Value', size=250),
-        'context': fields.Char('Context Value', size=250),
-        'res_model': fields.Char('Model', size=64),
-        'src_model': fields.Char('Source model', size=64),
-        'view_type': fields.Selection([('tree','Tree'), ('form','Form')],
-            string='Type of view'),
-        'usage': fields.Char('Action Usage', size=32),
-        'act_window_views': fields.One2Many('ir.action.act_window.view',
-            'act_window', 'Views'),
-        'views': fields.Function('views_get_fnc', type='binary',
-            string='Views'),
-        'limit': fields.Integer('Limit',
-            help='Default limit for the list view'),
-        'auto_refresh': fields.Integer('Auto-Refresh',
-            help='Add an auto-refresh on the view'),
-        'action': fields.Many2One('ir.action', 'Action', required=True),
-    }
+    domain = fields.Char('Domain Value', size=250)
+    context = fields.Char('Context Value', size=250)
+    res_model = fields.Char('Model', size=64)
+    src_model = fields.Char('Source model', size=64)
+    view_type = fields.Selection([('tree','Tree'), ('form','Form')],
+       string='Type of view')
+    usage = fields.Char('Action Usage', size=32)
+    act_window_views = fields.One2Many('ir.action.act_window.view',
+       'act_window', 'Views')
+    views = fields.Function('views_get_fnc', type='binary',
+       string='Views')
+    limit = fields.Integer('Limit',
+       help='Default limit for the list view')
+    auto_refresh = fields.Integer('Auto-Refresh',
+       help='Add an auto-refresh on the view')
+    action = fields.Many2One('ir.action', 'Action', required=True)
     _defaults = {
         'type': lambda *a: 'ir.action.act_window',
         'view_type': lambda *a: 'form',
@@ -265,15 +257,13 @@ class ActionActWindowView(OSV):
     _name = 'ir.action.act_window.view'
     _rec_name = 'view'
     _description = __doc__
-    _columns = {
-        'sequence': fields.Integer('Sequence'),
-        'view': fields.Many2One('ir.ui.view', 'View', required=True),
-        'act_window': fields.Many2One('ir.action.act_window', 'Action',
-            ondelete='CASCADE'),
-        'multi': fields.Boolean('On multiple doc.',
-            help="If set to true, the action will not be displayed \n" \
-                    "on the right toolbar of a form views."),
-    }
+    sequence = fields.Integer('Sequence')
+    view = fields.Many2One('ir.ui.view', 'View', required=True)
+    act_window = fields.Many2One('ir.action.act_window', 'Action',
+       ondelete='CASCADE')
+    multi = fields.Boolean('On multiple doc.',
+       help="If set to true, the action will not be displayed \n" \
+               "on the right toolbar of a form views.")
     _defaults = {
         'multi': lambda *a: False,
     }
@@ -288,10 +278,8 @@ class ActionWizard(OSV):
     _sequence = 'ir_action_id_seq'
     _description = __doc__
     _inherits = {'ir.action': 'action'}
-    _columns = {
-        'wiz_name': fields.char('Wizard name', size=64, required=True),
-        'action': fields.many2one('ir.action', 'Action', required=True),
-    }
+    wiz_name = fields.char('Wizard name', size=64, required=True)
+    action = fields.many2one('ir.action', 'Action', required=True)
     _defaults = {
         'type': lambda *a: 'ir.action.wizard',
     }
@@ -305,14 +293,12 @@ class ActionURL(OSV):
     _sequence = 'ir_action_id_seq'
     _description = __doc__
     _inherits = {'ir.action': 'action'}
-    _columns = {
-        'url': fields.text('Action Url',required=True),
-        'target': fields.selection([
-            ('new', 'New Window'),
-            ('self', 'This Window'),
-            ], 'Action Target', required=True),
-        'action': fields.many2one('ir.action', 'Action', required=True),
-    }
+    url = fields.text('Action Url',required=True)
+    target = fields.selection([
+       ('new', 'New Window'),
+       ('self', 'This Window'),
+       ], 'Action Target', required=True)
+    action = fields.many2one('ir.action', 'Action', required=True)
     _defaults = {
         'type': lambda *a: 'ir.action.act_url',
         'target': lambda *a: 'new',
diff --git a/trytond/ir/attachment.py b/trytond/ir/attachment.py
index 3de315d2c9..a149da122d 100644
--- a/trytond/ir/attachment.py
+++ b/trytond/ir/attachment.py
@@ -9,21 +9,19 @@ class Attachment(OSV):
     "Attachment"
     _name = 'ir.attachment'
     _description = __doc__
-    _columns = {
-        'name': fields.Char('Attachment Name',size=64, required=True),
-        'datas': fields.Function('datas', fnct_inv='datas_inv',
-            type='binary', string='Datas'),
-        'description': fields.Text('Description'),
-        'res_model': fields.Char('Resource Model',size=64,
-            readonly=True, required=True),
-        'res_id': fields.Integer('Resource ID', readonly=True,
-            required=True),
-        'link': fields.Char('Link', size=256),
-        'digest': fields.Char('Digest', size=32),
-        'collision': fields.Integer('Collision'),
-        'datas_size': fields.Function('datas', type='integer',
-            string='Datas size'),
-    }
+    name = fields.Char('Attachment Name',size=64, required=True)
+    datas = fields.Function('datas', fnct_inv='datas_inv',
+       type='binary', string='Datas')
+    description = fields.Text('Description')
+    res_model = fields.Char('Resource Model',size=64,
+       readonly=True, required=True)
+    res_id = fields.Integer('Resource ID', readonly=True,
+       required=True)
+    link = fields.Char('Link', size=256)
+    digest = fields.Char('Digest', size=32)
+    collision = fields.Integer('Collision')
+    datas_size = fields.Function('datas', type='integer',
+       string='Datas size')
     _defaults = {
         'collision': lambda *a: 0,
     }
diff --git a/trytond/ir/cron.py b/trytond/ir/cron.py
index 19fa867d36..e1d137c9da 100644
--- a/trytond/ir/cron.py
+++ b/trytond/ir/cron.py
@@ -27,31 +27,28 @@ class Cron(OSV, Agent):
     "Cron"
     _name = "ir.cron"
     _description = __doc__
-    _columns = {
-        'name': fields.char('Name', size=60, required=True),
-        'user': fields.many2one('res.user', 'User', required=True),
-        'active': fields.boolean('Active'),
-        'interval_number': fields.integer('Interval Number'),
-        'interval_type': fields.selection( [
-            ('minutes', 'Minutes'),
-            ('hours', 'Hours'),
-            ('days', 'Days'),
-            ('weeks', 'Weeks'),
-            ('months', 'Months'),
-            ], 'Interval Unit'),
-        'numbercall': fields.integer('Number of calls',
-            help='Number of time the function is called,\n' \
-                    'a negative number indicates that the function ' \
-                    'will always be called'),
-        'doall' : fields.boolean('Repeat missed'),
-        'nextcall' : fields.datetime('Next call date', required=True),
-        'model': fields.char('Model', size=64),
-        'function': fields.char('Function', size=64),
-        'args': fields.text('Arguments'),
-        'priority': fields.integer('Priority',
-            help='0=Very Urgent\n10=Not urgent')
-    }
-
+    name = fields.Char('Name', size=60, required=True)
+    user = fields.Many2One('res.user', 'User', required=True)
+    active = fields.Boolean('Active')
+    interval_number = fields.Integer('Interval Number')
+    interval_type = fields.Selection( [
+       ('minutes', 'Minutes'),
+       ('hours', 'Hours'),
+       ('days', 'Days'),
+       ('weeks', 'Weeks'),
+       ('months', 'Months'),
+       ], 'Interval Unit')
+    numbercall = fields.Integer('Number of calls',
+       help='Number of time the function is called,\n' \
+               'a negative number indicates that the function ' \
+               'will always be called')
+    doall = fields.Boolean('Repeat missed')
+    nextcall = fields.DateTime('Next call date', required=True)
+    model = fields.Char('Model', size=64)
+    function = fields.Char('Function', size=64)
+    args = fields.Text('Arguments')
+    priority = fields.Integer('Priority',
+       help='0=Very Urgent\n10=Not urgent')
     _defaults = {
         'nextcall' : lambda *a: time.strftime('%Y-%m-%d %H:%M:%S'),
         'priority' : lambda *a: 5,
diff --git a/trytond/ir/default.py b/trytond/ir/default.py
index 0d93a14824..9e823dcc1f 100644
--- a/trytond/ir/default.py
+++ b/trytond/ir/default.py
@@ -7,15 +7,13 @@ class Default(OSV):
     _name = 'ir.default'
     _description = __doc__
     _rec_name = 'value'
-    _columns = {
-        'model': fields.Many2One('ir.model', 'Model', required=True,
-            ondelete='cascade'),
-        'field': fields.Many2One('ir.model.field', 'Field', required=True,
-            ondelete='cascade'),
-        'value': fields.Text('Value'),
-        'clause': fields.Text('Clause'),
-        'user': fields.Many2One('res.user', 'User', ondelete='cascade'),
-    }
+    model = fields.Many2One('ir.model', 'Model', required=True,
+       ondelete='cascade')
+    field = fields.Many2One('ir.model.field', 'Field', required=True,
+       ondelete='cascade')
+    value = fields.Text('Value')
+    clause = fields.Text('Clause')
+    user = fields.Many2One('res.user', 'User', ondelete='cascade')
 
     def get_default(self, cursor, user, model, clause, context=None):
         res = {}
diff --git a/trytond/ir/export.py b/trytond/ir/export.py
index 7fc08c6f8d..7610b1691b 100644
--- a/trytond/ir/export.py
+++ b/trytond/ir/export.py
@@ -6,12 +6,10 @@ class Export(OSV):
     "Export"
     _name = "ir.export"
     _description = __doc__
-    _columns = {
-            'name': fields.char('Export name', size=128),
-            'resource': fields.char('Resource', size=128),
-            'export_fields': fields.one2many('ir.export.line', 'export',
-                'Export Id'),
-    }
+    name = fields.char('Export name', size=128)
+    resource = fields.char('Resource', size=128)
+    export_fields = fields.one2many('ir.export.line', 'export',
+       'Export Id')
 
 Export()
 
@@ -20,10 +18,8 @@ class ExportLine(OSV):
     "Export line"
     _name = 'ir.export.line'
     _description = __doc__
-    _columns = {
-            'name': fields.char('Field name', size=64),
-            'export': fields.many2one('ir.export', 'Exportation',
-                select=True),
-            }
+    name = fields.char('Field name', size=64)
+    export = fields.many2one('ir.export', 'Exportation',
+       select=True)
 
 ExportLine()
diff --git a/trytond/ir/lang.py b/trytond/ir/lang.py
index 4d56a88764..dd80833951 100644
--- a/trytond/ir/lang.py
+++ b/trytond/ir/lang.py
@@ -7,16 +7,14 @@ class Lang(OSV):
     _name = "ir.lang"
     _log_access = False
     _description = __doc__
-    _columns = {
-        'name': fields.Char('Name', size=64, required=True),
-        'code': fields.Char('Code', size=5, required=True),
-        'translatable': fields.Boolean('Translatable'),
-        'active': fields.Boolean('Active'),
-        'direction': fields.Selection([
-            ('ltr', 'Left-to-right'),
-            ('rtl', 'Right-to-left'),
-            ], 'Direction',required=True),
-    }
+    name = fields.Char('Name', size=64, required=True)
+    code = fields.Char('Code', size=5, required=True)
+    translatable = fields.Boolean('Translatable')
+    active = fields.Boolean('Active')
+    direction = fields.Selection([
+       ('ltr', 'Left-to-right'),
+       ('rtl', 'Right-to-left'),
+       ], 'Direction',required=True)
     _defaults = {
         'active': lambda *a: 1,
         'translatable': lambda *a: 0,
diff --git a/trytond/ir/model.py b/trytond/ir/model.py
index cfd6cafb18..6ded9f71a0 100644
--- a/trytond/ir/model.py
+++ b/trytond/ir/model.py
@@ -19,13 +19,11 @@ class Model(OSV):
     "Model"
     _name = 'ir.model'
     _description = __doc__
-    _columns = {
-        'name': fields.Char('Model name', size=64, translate=True),
-        'model': fields.Char('Object name', size=64, required=True),
-        'info': fields.Text('Information'),
-        'fields': fields.One2Many('ir.model.field', 'model', 'Fields',
-            required=True),
-    }
+    name = fields.Char('Model name', size=64, translate=True)
+    model = fields.Char('Object name', size=64, required=True)
+    info = fields.Text('Information')
+    fields = fields.One2Many('ir.model.field', 'model', 'Fields',
+       required=True)
     _defaults = {
         'name': lambda *a: 'No Name',
     }
@@ -36,22 +34,19 @@ class ModelField(OSV):
     "Model field"
     _name = 'ir.model.field'
     _description = __doc__
-    _columns = {
-        'name': fields.Char('Name', size=64),
-        'relation': fields.Char('Model Relation', size=64),
-        'model': fields.Many2One('ir.model', 'Model', required=True,
-            select=True, ondelete='cascade'),
-        'field_description': fields.Char('Field Description', size=256,
-            translate=True),
-        'ttype': fields.Char('Field Type', size=64),
-        'relate': fields.Boolean('Click and Relate'),
-
-        'groups': fields.Many2Many('res.group', 'ir_model_field_group_rel',
-            'field_id', 'group_id', 'Groups'),
-        'group_name': fields.Char('Group Name', size=128),
-        'view_load': fields.Boolean('View Auto-Load'),
-        'help': fields.Text('Help', translate=True),
-    }
+    name = fields.Char('Name', size=64)
+    relation = fields.Char('Model Relation', size=64)
+    model = fields.Many2One('ir.model', 'Model', required=True,
+       select=True, ondelete='cascade')
+    field_description = fields.Char('Field Description', size=256,
+       translate=True)
+    ttype = fields.Char('Field Type', size=64)
+    relate = fields.Boolean('Click and Relate')
+    groups = fields.Many2Many('res.group', 'ir_model_field_group_rel',
+       'field_id', 'group_id', 'Groups')
+    group_name = fields.Char('Group Name', size=128)
+    view_load = fields.Boolean('View Auto-Load')
+    help = fields.Text('Help', translate=True)
     _defaults = {
         'relate': lambda *a: 0,
         'view_load': lambda *a: 0,
@@ -68,15 +63,13 @@ class ModelAccess(OSV):
     _name = 'ir.model.access'
     _description = __doc__
     _rec_name = 'model'
-    _columns = {
-        'model': fields.Many2One('ir.model', 'Model', required=True),
-        'group': fields.Many2One('res.group', 'Group'),
-        'perm_read': fields.Boolean('Read Access'),
-        'perm_write': fields.Boolean('Write Access'),
-        'perm_create': fields.Boolean('Create Access'),
-        'perm_unlink': fields.Boolean('Delete Permission'),
-        'description': fields.Text('Description'),
-    }
+    model = fields.Many2One('ir.model', 'Model', required=True)
+    group = fields.Many2One('res.group', 'Group')
+    perm_read = fields.Boolean('Read Access')
+    perm_write = fields.Boolean('Write Access')
+    perm_create = fields.Boolean('Create Access')
+    perm_unlink = fields.Boolean('Delete Permission')
+    description = fields.Text('Description')
     _sql_constraints = [
         ('model_group_uniq', 'UNIQUE("model", "group")',
             'Only on record by model and group is allowed!'),
@@ -160,17 +153,15 @@ class ModelData(OSV):
     "Model data"
     _name = 'ir.model.data'
     _description = __doc__
-    _columns = {
-        'fs_id': fields.Char('Identifier on File System', required=True,
-            size=64, help="The id of the record as known on the file system."),
-        'model': fields.Char('Model', required=True, size=64),
-        'module': fields.Char('Module', required=True, size=64),
-        'db_id': fields.Integer('Resource ID',
-            help="The id of the record in the database."),
-        'date_update': fields.DateTime('Update Date'),
-        'date_init': fields.DateTime('Init Date'),
-        'values': fields.Text('Values'),
-    }
+    fs_id = fields.Char('Identifier on File System', required=True,
+       size=64, help="The id of the record as known on the file system.")
+    model = fields.Char('Model', required=True, size=64)
+    module = fields.Char('Module', required=True, size=64)
+    db_id = fields.Integer('Resource ID',
+       help="The id of the record in the database.")
+    date_update = fields.DateTime('Update Date')
+    date_init = fields.DateTime('Init Date')
+    values = fields.Text('Values')
     _defaults = {
         'date_init': lambda *a: time.strftime('%Y-%m-%d %H:%M:%S'),
     }
diff --git a/trytond/ir/module/category.py b/trytond/ir/module/category.py
index c3f30dd6ce..5deee3d872 100644
--- a/trytond/ir/module/category.py
+++ b/trytond/ir/module/category.py
@@ -6,13 +6,11 @@ class Category(OSV):
     "Module Category"
     _name = "ir.module.category"
     _description = __doc__
-    _columns = {
-        'name': fields.Char("Name", size=128, required=True),
-        'parent': fields.Many2One('ir.module.category',
-            'Parent Category', select=1),
-        'childs': fields.One2Many('ir.module.category',
-            'parent', 'Parent Category'),
-    }
+    name = fields.Char("Name", size=128, required=True)
+    parent = fields.Many2One('ir.module.category',
+       'Parent Category', select=1)
+    childs = fields.One2Many('ir.module.category',
+       'parent', 'Parent Category')
     _order = 'name'
 
 Category()
diff --git a/trytond/ir/module/module.py b/trytond/ir/module/module.py
index 145c9fce0d..9116a22ce0 100644
--- a/trytond/ir/module/module.py
+++ b/trytond/ir/module/module.py
@@ -126,33 +126,31 @@ class Module(OSV):
     "Module"
     _name = "ir.module.module"
     _description = __doc__
-    _columns = {
-        'name': fields.Char("Name", size=128, readonly=True, required=True),
-        'category': fields.Many2One('ir.module.category', 'Category',
-            readonly=True),
-        'shortdesc': fields.Char('Short description', size=256, readonly=True),
-        'description': fields.Text("Description", readonly=True),
-        'author': fields.Char("Author", size=128, readonly=True),
-        'website': fields.Char("Website", size=256, readonly=True),
-        'installed_version': fields.Function('get_installed_version',
-            string='Installed version', type='char'),
-        'latest_version': fields.Char('Latest version', size=64, readonly=True),
-        'url': fields.Char('URL', size=128),
-        'dependencies': fields.One2Many('ir.module.module.dependency',
-            'module', 'Dependencies', readonly=True),
-        'state': fields.Selection([
-            ('uninstallable', 'Not Installable'),
-            ('uninstalled', 'Not Installed'),
-            ('installed', 'Installed'),
-            ('to upgrade', 'To be upgraded'),
-            ('to remove', 'To be removed'),
-            ('to install', 'To be installed'),
-        ], string='State', readonly=True),
-        'demo': fields.Boolean('Demo data'),
-        'license': fields.Selection([('GPL-2', 'GPL-2'),
-            ('Other proprietary', 'Other proprietary')], string='License',
-            readonly=True),
-    }
+    name = fields.Char("Name", size=128, readonly=True, required=True)
+    category = fields.Many2One('ir.module.category', 'Category',
+        readonly=True)
+    shortdesc = fields.Char('Short description', size=256, readonly=True)
+    description = fields.Text("Description", readonly=True)
+    author = fields.Char("Author", size=128, readonly=True)
+    website = fields.Char("Website", size=256, readonly=True)
+    installed_version = fields.Function('get_installed_version',
+        string='Installed version', type='char')
+    latest_version = fields.Char('Latest version', size=64, readonly=True)
+    url = fields.Char('URL', size=128)
+    dependencies = fields.One2Many('ir.module.module.dependency',
+        'module', 'Dependencies', readonly=True)
+    state = fields.Selection([
+        ('uninstallable', 'Not Installable'),
+        ('uninstalled', 'Not Installed'),
+        ('installed', 'Installed'),
+        ('to upgrade', 'To be upgraded'),
+        ('to remove', 'To be removed'),
+        ('to install', 'To be installed'),
+        ], string='State', readonly=True)
+    demo = fields.Boolean('Demo data')
+    license = fields.Selection([('GPL-2', 'GPL-2'),
+        ('Other proprietary', 'Other proprietary')], string='License',
+        readonly=True)
     _defaults = {
         'state': lambda *a: 'uninstalled',
         'demo': lambda *a: False,
@@ -542,23 +540,21 @@ class ModuleDependency(OSV):
     "Module dependency"
     _name = "ir.module.module.dependency"
     _description = __doc__
-    _columns = {
-        'name': fields.Char('Name',  size=128),
-        'module': fields.Many2One('ir.module.module', 'Module', select=1,
-            ondelete='cascade'),
-        'state': fields.Function('state', type='selection',
-            selection=[
-            ('uninstallable','Uninstallable'),
-            ('uninstalled','Not Installed'),
-            ('installed','Installed'),
-            ('to upgrade','To be upgraded'),
-            ('to remove','To be removed'),
-            ('to install','To be installed'),
-            ('unknown', 'Unknown'),
-            ], string='State', readonly=True),
-    }
+    name = fields.Char('Name',  size=128)
+    module = fields.Many2One('ir.module.module', 'Module', select=1,
+       ondelete='cascade')
+    state = fields.Function('get_state', type='selection',
+       selection=[
+       ('uninstallable','Uninstallable'),
+       ('uninstalled','Not Installed'),
+       ('installed','Installed'),
+       ('to upgrade','To be upgraded'),
+       ('to remove','To be removed'),
+       ('to install','To be installed'),
+       ('unknown', 'Unknown'),
+       ], string='State', readonly=True)
 
-    def state(self, cursor, user, ids, name, args, context=None):
+    def get_state(self, cursor, user, ids, name, args, context=None):
         result = {}
         module_obj = self.pool.get('ir.module.module')
         for dependency in self.browse(cursor, user, ids):
@@ -577,19 +573,15 @@ ModuleDependency()
 
 class ModuleUpdateListInit(WizardOSV):
     _name = 'ir.module.module.update_list.init'
-    _columns = {
-        'repositories': fields.Text('Repositories', readonly=True),
-    }
+    repositories = fields.Text('Repositories', readonly=True)
 
 ModuleUpdateListInit()
 
 
 class ModuleUpdateListUpdate(WizardOSV):
     _name = 'ir.module.module.update_list.update'
-    _columns = {
-        'update': fields.Integer('Number of modules updated', readonly=True),
-        'add': fields.Integer('Number of modules added', readonly=True),
-    }
+    update = fields.Integer('Number of modules updated', readonly=True)
+    add = fields.Integer('Number of modules added', readonly=True)
 
 ModuleUpdateListUpdate()
 
@@ -660,18 +652,14 @@ ModuleUpdateList()
 
 class ModuleInstallUpgradeInit(WizardOSV):
     _name = 'ir.module.module.install_upgrade.init'
-    _columns = {
-        'module_info': fields.Text('Modules to update', readonly=True),
-        'module_download': fields.Text('Modules to download', readonly=True),
-    }
+    module_info = fields.Text('Modules to update', readonly=True)
+    module_download = fields.Text('Modules to download', readonly=True)
 
 ModuleInstallUpgradeInit()
 
 
 class ModuleInstallUpgradeStart(WizardOSV):
     _name = 'ir.module.module.install_upgrade.start'
-    _columns = {
-    }
 
 ModuleInstallUpgradeStart()
 
diff --git a/trytond/ir/module/repository.py b/trytond/ir/module/repository.py
index a6b7729d28..8943b1ff46 100644
--- a/trytond/ir/module/repository.py
+++ b/trytond/ir/module/repository.py
@@ -6,17 +6,15 @@ class Repository(OSV):
     "Module repository"
     _name = "ir.module.repository"
     _description = __doc__
-    _columns = {
-        'name': fields.Char('Name', size=128),
-        'url': fields.Char('Url', size=256, required=True),
-        'sequence': fields.Integer('Sequence', required=True),
-        'filter': fields.Char('Filter', size=128, required=True,
-            help='Regexp to search module on the repository webpage:\n'
-            '- The first parenthesis must match the name of the module.\n'
-            '- The second parenthesis must match all the version number.\n'
-            '- The last parenthesis must match the extension of the module.'),
-        'active': fields.boolean('Active'),
-    }
+    name = fields.Char('Name', size=128)
+    url = fields.Char('Url', size=256, required=True)
+    sequence = fields.Integer('Sequence', required=True)
+    filter = fields.Char('Filter', size=128, required=True,
+       help='Regexp to search module on the repository webpage:\n'
+       '- The first parenthesis must match the name of the module.\n'
+       '- The second parenthesis must match all the version number.\n'
+       '- The last parenthesis must match the extension of the module.')
+    active = fields.boolean('Active')
     _defaults = {
         'sequence': lambda *a: 5,
         'filter': lambda *a: 'href="([a-zA-Z0-9_]+)-' \
diff --git a/trytond/ir/property.py b/trytond/ir/property.py
index e500e97043..0f436654a9 100644
--- a/trytond/ir/property.py
+++ b/trytond/ir/property.py
@@ -6,13 +6,11 @@ class Property(OSV):
     "Property"
     _name = 'ir.property'
     _description = __doc__
-    _columns = {
-        'name': fields.Char('Name', size=128),
-        'value': fields.Reference('Value', selection='models_get2', size=128),
-        'res': fields.Reference('Resource', selection='models_get', size=128),
-        'field': fields.Many2One('ir.model.field', 'Field',
-            ondelete='cascade', required=True)
-    }
+    name = fields.Char('Name', size=128)
+    value = fields.Reference('Value', selection='models_get2', size=128)
+    res = fields.Reference('Resource', selection='models_get', size=128)
+    field = fields.Many2One('ir.model.field', 'Field',
+       ondelete='cascade', required=True)
 
     def __init__(self, pool):
         super(Property, self).__init__(pool)
diff --git a/trytond/ir/rule.py b/trytond/ir/rule.py
index efec1c3714..8325e2650a 100644
--- a/trytond/ir/rule.py
+++ b/trytond/ir/rule.py
@@ -8,23 +8,21 @@ class RuleGroup(OSV):
     "Rule group"
     _name = 'ir.rule.group'
     _description = __doc__
-    _columns = {
-        'name': fields.Char('Name', size=128, select=1),
-        'model': fields.Many2One('ir.model', 'Model', select=1,
-            required=True),
-        'global': fields.Boolean('Global', select=1,
-            help="Make the rule global \n" \
-                    "or it needs to be put on a group or user"),
-        'rules': fields.One2Many('ir.rule', 'rule_group', 'Tests',
-            help="The rule is satisfied if at least one test is True"),
-        'groups': fields.Many2Many('res.group', 'group_rule_group_rel',
-            'rule_group_id', 'group_id', 'Groups'),
-        'users': fields.Many2Many('res.user', 'user_rule_group_rel',
-            'rule_group_id', 'user_id', 'Users'),
-    }
-    _order = 'model, global DESC'
+    name = fields.Char('Name', size=128, select=1)
+    model = fields.Many2One('ir.model', 'Model', select=1,
+       required=True)
+    global_p = fields.Boolean('Global', select=1,
+       help="Make the rule global \n" \
+               "or it needs to be put on a group or user")
+    rules = fields.One2Many('ir.rule', 'rule_group', 'Tests',
+       help="The rule is satisfied if at least one test is True")
+    groups = fields.Many2Many('res.group', 'group_rule_group_rel',
+       'rule_group_id', 'group_id', 'Groups')
+    users = fields.Many2Many('res.user', 'user_rule_group_rel',
+       'rule_group_id', 'user_id', 'Users')
+    _order = 'model, global_p DESC'
     _defaults = {
-        'global': lambda *a: True,
+        'global_p': lambda *a: True,
     }
 
     def unlink(self, cursor, user, ids, context=None):
@@ -56,22 +54,20 @@ class Rule(OSV):
     _name = 'ir.rule'
     _rec_name = 'field'
     _description = __doc__
-    _columns = {
-        'field': fields.Many2One('ir.model.field', 'Field',
-            domain="[('model', '=', parent.model)]", select=1,
-            required=True),
-        'operator':fields.Selection([
-            ('=', '='),
-            ('<>', '<>'),
-            ('<=', '<='),
-            ('>=', '>='),
-            ('in', 'in'),
-            ('child_of', 'child_of'),
-            ], 'Operator', required=True),
-        'operand':fields.Selection('operand','Operand', size=64, required=True),
-        'rule_group': fields.Many2One('ir.rule.group', 'Group', select=2,
-            required=True, ondelete="cascade")
-    }
+    field = fields.Many2One('ir.model.field', 'Field',
+       domain="[('model', '=', parent.model)]", select=1,
+       required=True)
+    operator = fields.Selection([
+       ('=', '='),
+       ('<>', '<>'),
+       ('<=', '<='),
+       ('>=', '>='),
+       ('in', 'in'),
+       ('child_of', 'child_of'),
+       ], 'Operator', required=True)
+    operand = fields.Selection('get_operand','Operand', size=64, required=True)
+    rule_group = fields.Many2One('ir.rule.group', 'Group', select=2,
+       required=True, ondelete="cascade")
 
     def __init__(self, pool):
         super(Rule, self).__init__(pool)
@@ -120,7 +116,7 @@ class Rule(OSV):
 
         return res
 
-    def operand(self, cursor, user, context):
+    def get_operand(self, cursor, user, context):
         res = []
         operands = self._operand_get(cursor, user, 'res.user', level=1,
                 recur=['many2one'], root_tech='user', root='User')
@@ -146,7 +142,7 @@ class Rule(OSV):
                                 "JOIN res_group_user_rel u_rel " \
                                     "ON (g_rel.group_id = u_rel.gid) " \
                                 "WHERE u_rel.uid = %d) "
-                    "OR g.global)", (model_name, user, user))
+                    "OR g.global_p)", (model_name, user, user))
         ids = [x[0] for x in cursor.fetchall()]
         if not ids:
             return '', []
@@ -170,7 +166,7 @@ class Rule(OSV):
                         {'user': self.pool.get('res.user').browse(cursor, 0,
                             user), 'time': time})
 
-            if rule.rule_group['global']:
+            if rule.rule_group['global_p']:
                 clause_global.setdefault(rule.rule_group.id, [])
                 clause_global[rule.rule_group.id].append(
                         obj._where_calc(cursor, user, dom, active_test=False))
diff --git a/trytond/ir/rule.xml b/trytond/ir/rule.xml
index 54a0e46afe..c60159f9ce 100644
--- a/trytond/ir/rule.xml
+++ b/trytond/ir/rule.xml
@@ -9,8 +9,8 @@
                 <form string="Record rules">
                     <label name="model"/>
                     <field name="model"/>
-                    <label name="global"/>
-                    <field name="global"/>
+                    <label name="global_p"/>
+                    <field name="global_p"/>
                     <label name="name"/>
                     <field name="name" colspan="3"/>
                     <field name="rules" colspan="4"/>
@@ -30,7 +30,7 @@
                 <tree string="Record rules">
                     <field name="model"/>
                     <field name="name"/>
-                    <field name="global"/>
+                    <field name="global_p"/>
                 </tree>
               ]]>
             </field>
diff --git a/trytond/ir/sequence.py b/trytond/ir/sequence.py
index 159fe14e17..d2b2ed40bf 100644
--- a/trytond/ir/sequence.py
+++ b/trytond/ir/sequence.py
@@ -6,10 +6,8 @@ class SequenceType(OSV):
     "Sequence type"
     _name = 'ir.sequence.type'
     _description = __doc__
-    _columns = {
-        'name': fields.Char('Sequence Name',size=64, required=True),
-        'code': fields.Char('Sequence Code',size=32, required=True),
-    }
+    name = fields.Char('Sequence Name',size=64, required=True)
+    code = fields.Char('Sequence Code',size=32, required=True)
 
 SequenceType()
 
@@ -18,17 +16,15 @@ class Sequence(OSV):
     "Sequence"
     _name = 'ir.sequence'
     _description = __doc__
-    _columns = {
-        'name': fields.Char('Sequence Name',size=64, required=True),
-        'code': fields.Selection('code_get', 'Sequence Code',size=64,
-            required=True),
-        'active': fields.Boolean('Active'),
-        'prefix': fields.Char('Prefix',size=64),
-        'suffix': fields.Char('Suffix',size=64),
-        'number_next': fields.Integer('Next Number', required=True),
-        'number_increment': fields.Integer('Increment Number', required=True),
-        'padding' : fields.Integer('Number padding', required=True),
-    }
+    name = fields.Char('Sequence Name',size=64, required=True)
+    code = fields.Selection('code_get', 'Sequence Code',size=64,
+       required=True)
+    active = fields.Boolean('Active')
+    prefix = fields.Char('Prefix',size=64)
+    suffix = fields.Char('Suffix',size=64)
+    number_next = fields.Integer('Next Number', required=True)
+    number_increment = fields.Integer('Increment Number', required=True)
+    padding = fields.Integer('Number padding', required=True)
     _defaults = {
         'active': lambda *a: True,
         'number_increment': lambda *a: 1,
diff --git a/trytond/ir/translation.py b/trytond/ir/translation.py
index 4acb0bbccd..a7eff0681b 100644
--- a/trytond/ir/translation.py
+++ b/trytond/ir/translation.py
@@ -29,19 +29,17 @@ class Translation(OSV, Cacheable):
     "Translation"
     _name = "ir.translation"
     _description = __doc__
-    _columns = {
-        'name': fields.Char('Field Name', size=128, required=True),
-        'res_id': fields.Integer('Resource ID'),
-        'lang': fields.Selection('get_language', string='Language', size=5),
-        'type': fields.Selection(TRANSLATION_TYPE, string='Type', size=16,
-            required=True),
-        'src': fields.Text('Source'),
-        'value': fields.Text('Translation Value'),
-        'module': fields.Char('Module', size=128, readonly=True),
-        'fuzzy': fields.Boolean('Fuzzy'),
-        'model': fields.Function('model', fnct_search='model_search',
-            type='char', string='Model'),
-    }
+    name = fields.Char('Field Name', size=128, required=True)
+    res_id = fields.Integer('Resource ID')
+    lang = fields.Selection('get_language', string='Language', size=5),
+    type = fields.Selection(TRANSLATION_TYPE, string='Type', size=16,
+       required=True)
+    src = fields.Text('Source')
+    value = fields.Text('Translation Value')
+    module = fields.Char('Module', size=128, readonly=True)
+    fuzzy = fields.Boolean('Fuzzy')
+    model = fields.Function('get_model', fnct_search='model_search',
+       type='char', string='Model')
     _defaults = {
         'fuzzy': lambda *a: 0,
     }
@@ -61,7 +59,7 @@ class Translation(OSV, Cacheable):
                 'get_language',
             ]
 
-    def model(self, cursor, user, ids, name, arg, context=None):
+    def get_model(self, cursor, user, ids, name, arg, context=None):
         res = {}
         for translation in self.browse(cursor, user, ids, context=context):
             res[translation.id] = translation.name.split(',')[0]
@@ -370,10 +368,8 @@ class TranslationUpdateInit(WizardOSV):
     "Update translation - language"
     _name = 'ir.translation.update.init'
     _description = __doc__
-    _columns = {
-        'lang': fields.Selection('get_language', string='Language', size=5,
-            required=True),
-    }
+    lang = fields.Selection('get_language', string='Language', size=5,
+        required=True)
 
     def __init__(self, pool):
         super(TranslationUpdateInit, self).__init__(pool)
@@ -501,12 +497,10 @@ class TranslationExportInit(WizardOSV):
     "Export translation - language and module"
     _name = 'ir.translation.export.init'
     _description = __doc__
-    _columns = {
-        'lang': fields.Selection('get_language', string='Language', size=5,
-            required=True),
-        'module': fields.Selection('get_module', string='Module', size=128,
-            required=True),
-    }
+    lang = fields.Selection('get_language', string='Language', size=5,
+       required=True)
+    module = fields.Selection('get_module', string='Module', size=128,
+       required=True)
 
     def __init__(self, pool):
         super(TranslationExportInit, self).__init__(pool)
@@ -538,9 +532,7 @@ class TranslationExportStart(WizardOSV):
     "Export translation - file"
     _description = __doc__
     _name = 'ir.translation.export.start'
-    _columns = {
-        'file': fields.Binary('File', readonly=True),
-    }
+    file = fields.Binary('File', readonly=True)
 
 TranslationExportStart()
 
diff --git a/trytond/ir/ui/menu.py b/trytond/ir/ui/menu.py
index a99eeeebc9..eded7153e7 100644
--- a/trytond/ir/ui/menu.py
+++ b/trytond/ir/ui/menu.py
@@ -125,25 +125,23 @@ class UIMenu(OSV):
     "UI menu"
     _name = 'ir.ui.menu'
     _description = __doc__
-    _columns = {
-        'name': fields.Char('Menu', size=64, required=True, translate=True),
-        'sequence': fields.Integer('Sequence'),
-        'childs' : fields.One2Many('ir.ui.menu', 'parent','Childs'),
-        'parent': fields.Many2One('ir.ui.menu', 'Parent Menu', select=1),
-        'groups': Many2ManyUniq('res.group', 'ir_ui_menu_group_rel',
-            'menu_id', 'gid', 'Groups'),
-        'complete_name': fields.Function('get_full_name',
-            string='Complete Name', type='char', size=128),
-        'icon': fields.selection(ICONS, 'Icon', size=64),
-        'action': fields.Function('action', fnct_inv='action_inv',
-            type='reference', string='Action',
-            selection=[
-                ('ir.action.report', 'ir.action.report'),
-                ('ir.action.act_window', 'ir.action.act_window'),
-                ('ir.action.wizard', 'ir.action.wizard'),
-                ('ir.action.url', 'ir.action.url'),
-                ]),
-    }
+    name = fields.Char('Menu', size=64, required=True, translate=True)
+    sequence = fields.Integer('Sequence')
+    childs = fields.One2Many('ir.ui.menu', 'parent','Childs')
+    parent = fields.Many2One('ir.ui.menu', 'Parent Menu', select=1)
+    groups = Many2ManyUniq('res.group', 'ir_ui_menu_group_rel',
+       'menu_id', 'gid', 'Groups')
+    complete_name = fields.Function('get_full_name',
+       string='Complete Name', type='char', size=128)
+    icon = fields.selection(ICONS, 'Icon', size=64)
+    action = fields.Function('get_action', fnct_inv='action_inv',
+       type='reference', string='Action',
+       selection=[
+           ('ir.action.report', 'ir.action.report'),
+           ('ir.action.act_window', 'ir.action.act_window'),
+           ('ir.action.wizard', 'ir.action.wizard'),
+           ('ir.action.url', 'ir.action.url'),
+           ])
     _defaults = {
         'icon' : lambda *a: 'STOCK_OPEN',
         'sequence' : lambda *a: 10,
@@ -165,7 +163,7 @@ class UIMenu(OSV):
             parent_path = ''
         return parent_path + menu.name
 
-    def action(self, cursor, user, ids, name, arg, context=None):
+    def get_action(self, cursor, user, ids, name, arg, context=None):
         res = {}
         for menu_id in ids:
             res[menu_id] = False
diff --git a/trytond/ir/ui/view.py b/trytond/ir/ui/view.py
index 73e5a694ed..cc3c2fc78b 100644
--- a/trytond/ir/ui/view.py
+++ b/trytond/ir/ui/view.py
@@ -9,19 +9,17 @@ class View(OSV):
     _name = 'ir.ui.view'
     _description = __doc__
     _rec_name = 'model'
-    _columns = {
-        'model': fields.Char('Model', size=64, required=True),
-        'priority': fields.Integer('Priority', required=True),
-        'type': fields.Selection((
-            ('tree','Tree'),
-            ('form','Form'),
-            ('graph', 'Graph'),
-            ('calendar', 'Calendar')), 'View Type', required=True),
-        'arch': fields.Text('View Architecture', required=True),
-        'inherit': fields.Many2One('ir.ui.view', 'Inherited View'),
-        'field_childs': fields.Char('Childs Field',size=64),
-        'module': fields.Char('Module', size=128, readonly=True),
-    }
+    model = fields.Char('Model', size=64, required=True)
+    priority = fields.Integer('Priority', required=True)
+    type = fields.Selection((
+       ('tree','Tree'),
+       ('form','Form'),
+       ('graph', 'Graph'),
+       ('calendar', 'Calendar')), 'View Type', required=True)
+    arch = fields.Text('View Architecture', required=True)
+    inherit = fields.Many2One('ir.ui.view', 'Inherited View')
+    field_childs = fields.Char('Childs Field',size=64)
+    module = fields.Char('Module', size=128, readonly=True)
     _defaults = {
         'arch': lambda *a: '<?xml version="1.0"?>\n' \
                 '<tree title="Unknwown">\n\t<field name="name"/>\n</tree>',
@@ -171,14 +169,12 @@ class ViewShortcut(OSV):
     "View shortcut"
     _name = 'ir.ui.view_sc'
     _description = __doc__
-    _columns = {
-        'name': fields.char('Shortcut Name', size=64, required=True),
-        'res_id': fields.integer('Resource Ref.', required=True),
-        'sequence': fields.integer('Sequence'),
-        'user_id': fields.many2one('res.user', 'User Ref.', required=True,
-            ondelete='cascade'),
-        'resource': fields.char('Resource Name', size=64, required=True)
-    }
+    name = fields.Char('Shortcut Name', size=64, required=True)
+    res_id = fields.Integer('Resource Ref.', required=True)
+    sequence = fields.Integer('Sequence')
+    user_id = fields.Many2One('res.user', 'User Ref.', required=True,
+       ondelete='cascade')
+    resource = fields.Char('Resource Name', size=64, required=True)
 
     def __init__(self, pool):
         super(ViewShortcut, self).__init__(pool)
diff --git a/trytond/osv/fields.py b/trytond/osv/fields.py
index 878d92ad94..1b7ab6dc9d 100644
--- a/trytond/osv/fields.py
+++ b/trytond/osv/fields.py
@@ -33,7 +33,7 @@ def _symbol_set(symb):
         return symb.encode('utf-8')
     return str(symb)
 
-class _column(object):
+class Column(object):
     _classic_read = True
     _classic_write = True
     _properties = False
@@ -75,7 +75,7 @@ class _column(object):
         raise Exception, 'undefined get method !'
 
 
-class Boolean(_column):
+class Boolean(Column):
     _type = 'boolean'
     _symbol_c = '%s'
     _symbol_f = lambda x: x and 'True' or 'False'
@@ -84,7 +84,7 @@ class Boolean(_column):
 boolean = Boolean
 
 
-class Integer(_column):
+class Integer(Column):
     _type = 'integer'
     _symbol_c = '%d'
     _symbol_f = lambda x: int(x or 0)
@@ -93,21 +93,21 @@ class Integer(_column):
 integer = Integer
 
 
-class Reference(_column):
+class Reference(Column):
     _type = 'reference'
 
     def __init__(self, string, selection, size, **args):
-        _column.__init__(self, string=string, size=size, selection=selection,
+        Column.__init__(self, string=string, size=size, selection=selection,
                 **args)
 
 reference = Reference
 
 
-class Char(_column):
+class Char(Column):
     _type = 'char'
 
     def __init__(self, string, size, **args):
-        _column.__init__(self, string=string, size=size, **args)
+        Column.__init__(self, string=string, size=size, **args)
         self._symbol_set = (self._symbol_c, self._symbol_set_char)
 
     def _symbol_set_char(self, symb):
@@ -134,44 +134,44 @@ class Char(_column):
 char = Char
 
 
-class Text(_column):
+class Text(Column):
     _type = 'text'
 
 text = Text
 
 
-class Float(_column):
+class Float(Column):
     _type = 'float'
     _symbol_c = '%f'
     _symbol_f = lambda x: __builtin__.float(x or 0.0)
     _symbol_set = (_symbol_c, _symbol_f)
 
     def __init__(self, string='unknown', digits=None, **args):
-        _column.__init__(self, string=string, **args)
+        Column.__init__(self, string=string, **args)
         self.digits = digits
 
 float = Float
 
 
-class Date(_column):
+class Date(Column):
     _type = 'date'
 
 date = Date
 
 
-class DateTime(_column):
+class DateTime(Column):
     _type = 'datetime'
 
 datetime = DateTime
 
 
-class Time(_column):
+class Time(Column):
     _type = 'time'
 
 time = Time
 
 
-class Binary(_column):
+class Binary(Column):
     _type = 'binary'
     _symbol_c = '%s'
     _symbol_f = lambda symb: symb and psycopg2.Binary(symb) or None
@@ -180,7 +180,7 @@ class Binary(_column):
 binary = Binary
 
 
-class Selection(_column):
+class Selection(Column):
     _type = 'selection'
 
     def __init__(self, selections, string='unknown', **args):
@@ -188,13 +188,13 @@ class Selection(_column):
         selections is a list of (key, string)
             or the name of the object function that return the list
         """
-        _column.__init__(self, string=string, **args)
+        Column.__init__(self, string=string, **args)
         self.selection = selections
 
 selection = Selection
 
 
-class One2One(_column):
+class One2One(Column):
     _classic_read = False
     _classic_write = True
     _type = 'one2one'
@@ -202,7 +202,7 @@ class One2One(_column):
     def __init__(self, obj, string='unknown', **args):
         warnings.warn("The one2one field doesn't work anymore",
                 DeprecationWarning)
-        _column.__init__(self, string=string, **args)
+        Column.__init__(self, string=string, **args)
         self._obj = obj
 
     def set(self, cursor, obj_src, src_id, field, act, user=None, context=None):
@@ -224,13 +224,13 @@ class One2One(_column):
 one2one = One2One
 
 
-class Many2One(_column):
+class Many2One(Column):
     _classic_read = False
     _classic_write = True
     _type = 'many2one'
 
     def __init__(self, obj, string='unknown', **args):
-        _column.__init__(self, string=string, **args)
+        Column.__init__(self, string=string, **args)
         self._obj = obj
 
     # TODO: speed improvement
@@ -299,13 +299,13 @@ class Many2One(_column):
 many2one = Many2One
 
 
-class One2Many(_column):
+class One2Many(Column):
     _classic_read = False
     _classic_write = False
     _type = 'one2many'
 
     def __init__(self, obj, fields_id, string='unknown', limit=None, **args):
-        _column.__init__(self, string=string, **args)
+        Column.__init__(self, string=string, **args)
         self._obj = obj
         self._fields_id = fields_id
         self._limit = limit
@@ -377,14 +377,14 @@ class One2Many(_column):
 one2many = One2Many
 
 
-class Many2Many(_column):
+class Many2Many(Column):
     _classic_read = False
     _classic_write = False
     _type = 'many2many'
 
     def __init__(self, obj, rel, id1, id2, string='unknown', limit=None,
             **args):
-        _column.__init__(self, string=string, **args)
+        Column.__init__(self, string=string, **args)
         self._obj = obj
         self._rel = rel
         self._id1 = id1
@@ -475,7 +475,7 @@ class Many2Many(_column):
 many2many = Many2Many
 
 
-class Function(_column):
+class Function(Column):
     _classic_read = False
     _classic_write = False
     _type = 'function'
@@ -483,7 +483,7 @@ class Function(_column):
 
     def __init__(self, fnct, arg=None, fnct_inv='', fnct_inv_arg=None,
             type='float', fnct_search='', obj=None, **args):
-        _column.__init__(self, **args)
+        Column.__init__(self, **args)
         self._obj = obj
         self._fnct = fnct
         self._fnct_inv = fnct_inv
@@ -519,7 +519,7 @@ class Function(_column):
 function = Function
 
 
-class Serialized(_column):
+class Serialized(Column):
     def __init__(self, string='unknown', serialize_func=repr,
             deserialize_func=eval, type='text', **args):
         self._serialize_func = serialize_func
diff --git a/trytond/osv/orm.py b/trytond/osv/orm.py
index 96227485d7..2a8e5ce7f3 100644
--- a/trytond/osv/orm.py
+++ b/trytond/osv/orm.py
@@ -241,7 +241,6 @@ class ORM(object):
             - relations (one2many, many2one, many2many)
             - functions
     """
-    _columns = {}
     _sql_constraints = []
     _constraints = []
     _defaults = {}
@@ -275,6 +274,21 @@ class ORM(object):
     _sql = ''
     _inherit_fields = []
     pool = None
+    __columns = None
+
+    def _getcolumns(self):
+        if self.__columns:
+            return self.__columns
+        res = {}
+        for attr in dir(self):
+            if attr == '_columns':
+                continue
+            if isinstance(getattr(self, attr), fields.Column):
+                res[attr] = getattr(self, attr)
+        self.__columns = res
+        return res
+
+    _columns = property(fget=_getcolumns)
 
     def _field_create(self, cursor, module_name):
         cursor.execute("SELECT id FROM ir_model WHERE model = %s",
@@ -759,6 +773,8 @@ class ORM(object):
                         cursor.commit()
 
     def __init__(self):
+        # reinit the cachel on _columns
+        self.__columns = None
         if not self._table:
             self._table = self._name.replace('.', '_')
         if not self._description:
@@ -771,15 +787,13 @@ class ORM(object):
             self._sequence = self._table+'_id_seq'
 
         if self._log_access:
-            if not self._columns:
-                self._columns = {}
-            self._columns['create_uid'] = fields.Many2One('res.user',
+            self.create_uid = fields.Many2One('res.user',
                     'Creation user', required=True, readonly=True)
-            self._columns['create_date'] = fields.DateTime('Creation date',
+            self.create_date = fields.DateTime('Creation date',
                     required=True, readonly=True)
-            self._columns['write_uid'] = fields.Many2One('res.user',
+            self.write_uid = fields.Many2One('res.user',
                        'Last modification by', readonly=True)
-            self._columns['write_date'] = fields.DateTime(
+            self.write_date = fields.DateTime(
                     'Last modification date', readonly=True)
             if not self._defaults:
                 self._defaults = {}
diff --git a/trytond/res/ir.xml b/trytond/res/ir.xml
index 1172f2ad05..651f2164e6 100644
--- a/trytond/res/ir.xml
+++ b/trytond/res/ir.xml
@@ -378,7 +378,7 @@
         </record>
         <record model="ir.rule.group" id="rule_group_menu">
             <field name="model" search="[('model', '=', 'ir.ui.menu')]"/>
-            <field name="global" eval="True"/>
+            <field name="global_p" eval="True"/>
         </record>
         <record model="ir.rule" id="rule_menu1">
             <field name="field" search="[('name', '=', 'groups'),('model.model', '=', 'ir.ui.menu')]"/>
@@ -394,7 +394,7 @@
         </record>
         <record model="ir.rule.group" id="rule_group_action">
             <field name="model" search="[('model', '=', 'ir.action')]"/>
-            <field name="global" eval="True"/>
+            <field name="global_p" eval="True"/>
         </record>
         <record model="ir.rule" id="rule_action1">
             <field name="field" search="[('name', '=', 'groups'),('model.model', '=', 'ir.action')]"/>
diff --git a/trytond/res/request.py b/trytond/res/request.py
index 69f83f311b..55a43978e1 100644
--- a/trytond/res/request.py
+++ b/trytond/res/request.py
@@ -7,56 +7,54 @@ class Request(OSV):
     _name = 'res.request'
     _table = 'res_request'
     _description = __doc__
-    _columns = {
-        'create_date': fields.DateTime('Created date', readonly=True),
-        'name': fields.Char('Subject', states={
-            'readonly': "state in ('waiting', 'active', 'closed')",
-            }, required=True, size=128),
-        'active': fields.Boolean('Active'),
-        'priority': fields.Selection([
-            ('0', 'Low'),
-            ('1', 'Normal'),
-            ('2', 'High'),
-            ], 'Priority', states={
-                'readonly': "state in ('waiting', 'closed')",
-                }, required=True),
-        'act_from': fields.Many2One('res.user', 'From', required=True,
-            readonly=True, states={
-                'readonly': "state == 'closed'",
-                }),
-        'act_to': fields.Many2One('res.user', 'To', required=True,
-            states={
-                'readonly': "state in ('waiting', 'closed')",
-                }),
-        'body': fields.Text('Request', states={
-            'readonly': "state in ('waiting', 'closed')",
-            }),
-        'date_sent': fields.DateTime('Date', readonly=True),
-        'trigger_date': fields.DateTime('Trigger Date', states={
-            'readonly': "state in ('waiting', 'closed')",
-            }),
-#        'ref_partner_id': fields.Many2One('res.partner', 'Partner Ref.',
-#            states={
-#                'closed': [('readonly', True)],
-#                }),
-        #TODO: use one2many instead limit number of reference
-        'ref_doc1': fields.Reference('Document Ref 1', selection='links_get',
-            size=128, states={
-                'readonly': "state == 'closed'",
-                }),
-        'ref_doc2': fields.Reference('Document Ref 2', selection='links_get',
-            size=128, states={
-                'readonly': "state == 'closed'",
-                }),
-        'state': fields.Selection([
-            ('draft', 'draft'),
-            ('waiting', 'waiting'),
-            ('active', 'active'),
-            ('closed', 'closed'),
-            ], 'State', required=True, readonly=True),
-        'history': fields.One2Many('res.request.history', 'request',
-                'History', readonly=True),
-    }
+    create_date = fields.DateTime('Created date', readonly=True)
+    name = fields.Char('Subject', states={
+       'readonly': "state in ('waiting', 'active', 'closed')",
+       }, required=True, size=128)
+    active = fields.Boolean('Active')
+    priority = fields.Selection([
+       ('0', 'Low'),
+       ('1', 'Normal'),
+       ('2', 'High'),
+       ], 'Priority', states={
+           'readonly': "state in ('waiting', 'closed')",
+           }, required=True)
+    act_from = fields.Many2One('res.user', 'From', required=True,
+       readonly=True, states={
+           'readonly': "state == 'closed'",
+           })
+    act_to = fields.Many2One('res.user', 'To', required=True,
+       states={
+           'readonly': "state in ('waiting', 'closed')",
+           })
+    body = fields.Text('Request', states={
+       'readonly': "state in ('waiting', 'closed')",
+       })
+    date_sent = fields.DateTime('Date', readonly=True)
+    trigger_date = fields.DateTime('Trigger Date', states={
+       'readonly': "state in ('waiting', 'closed')",
+       })
+#   'ref_partner_id': fields.Many2One('res.partner', 'Partner Ref.',
+#       states={
+#           'closed': [('readonly', True)],
+#           })
+#    TODO: use one2many instead limit number of reference
+    ref_doc1 = fields.Reference('Document Ref 1', selection='links_get',
+       size=128, states={
+           'readonly': "state == 'closed'",
+           })
+    ref_doc2 = fields.Reference('Document Ref 2', selection='links_get',
+       size=128, states={
+           'readonly': "state == 'closed'",
+           })
+    state = fields.Selection([
+       ('draft', 'draft'),
+       ('waiting', 'waiting'),
+       ('active', 'active'),
+       ('closed', 'closed'),
+       ], 'State', required=True, readonly=True)
+    history = fields.One2Many('res.request.history', 'request',
+           'History', readonly=True)
     _defaults = {
         'act_from': lambda obj, cursor, user, context: user,
         'state': lambda *a: 'draft',
@@ -139,11 +137,9 @@ class RequestLink(OSV):
     "Request link"
     _name = 'res.request.link'
     _description = __doc__
-    _columns = {
-        'name': fields.Char('Name', size=64, required=True, translate=True),
-        'object': fields.Char('Object', size=64, required=True),
-        'priority': fields.Integer('Priority'),
-    }
+    name = fields.Char('Name', size=64, required=True, translate=True)
+    object = fields.Char('Object', size=64, required=True)
+    priority = fields.Integer('Priority')
     _defaults = {
         'priority': lambda *a: 5,
     }
@@ -156,16 +152,14 @@ class RequestHistory(OSV):
     "Request history"
     _name = 'res.request.history'
     _description = __doc__
-    _columns = {
-        'name': fields.Char('Summary', size=128, required=True),
-        'request': fields.Many2One('res.request', 'Request', required=True,
-            ondelete='cascade', select=True),
-        'act_from': fields.Many2One('res.user', 'From', required=True,
-            readonly=True),
-        'act_to': fields.Many2One('res.user', 'To', required=True),
-        'body': fields.Text('Body'),
-        'date_sent': fields.DateTime('Date sent', required=True)
-    }
+    name = fields.Char('Summary', size=128, required=True)
+    request = fields.Many2One('res.request', 'Request', required=True,
+       ondelete='cascade', select=True)
+    act_from = fields.Many2One('res.user', 'From', required=True,
+       readonly=True)
+    act_to = fields.Many2One('res.user', 'To', required=True)
+    body = fields.Text('Body')
+    date_sent = fields.DateTime('Date sent', required=True)
     _defaults = {
         'name': lambda *a: 'NoName',
         'act_from': lambda obj, cursor, user, context: user,
diff --git a/trytond/res/user.py b/trytond/res/user.py
index c6db69ae36..bdce02777e 100644
--- a/trytond/res/user.py
+++ b/trytond/res/user.py
@@ -11,16 +11,14 @@ class Group(OSV):
     "Group"
     _name = "res.group"
     _description = __doc__
-    _columns = {
-        'name': fields.Char('Group Name', size=64, required=True),
-        'model_access': fields.One2Many('ir.model.access', 'group',
-            'Access Controls'),
-        'rule_groups': fields.Many2Many('ir.rule.group', 'group_rule_group_rel',
-            'group_id', 'rule_group_id', 'Rules',
-            domain="[('global', '<>', True)]"),
-        'menu_access': fields.Many2Many('ir.ui.menu', 'ir_ui_menu_group_rel',
-            'gid', 'menu_id', 'Access Menu'),
-    }
+    name = fields.Char('Group Name', size=64, required=True)
+    model_access = fields.One2Many('ir.model.access', 'group',
+       'Access Controls')
+    rule_groups = fields.Many2Many('ir.rule.group', 'group_rule_group_rel',
+       'group_id', 'rule_group_id', 'Rules',
+       domain="[('global', '<>', True)]")
+    menu_access = fields.Many2Many('ir.ui.menu', 'ir_ui_menu_group_rel',
+       'gid', 'menu_id', 'Access Menu')
     _sql_constraints = [
         ('name_uniq', 'unique (name)', 'The name of the group must be unique!')
     ]
@@ -39,23 +37,21 @@ class User(OSV):
     "User"
     _name = "res.user"
     _description = __doc__
-    _columns = {
-        'name': fields.Char('Name', size=64, required=True, select=1),
-        'login': fields.Char('Login', size=64, required=True),
-        'password': fields.Char('Password', size=64),
-        'signature': fields.Text('Signature', size=64),
-        #'address_id': fields.Many2One('res.partner.address', 'Address'),
-        'active': fields.Boolean('Active'),
-        'action': fields.Many2One('ir.action', 'Home Action'),
-        'menu': fields.Many2One('ir.action', 'Menu Action'),
-        'groups': fields.Many2Many('res.group', 'res_group_user_rel',
-            'uid', 'gid', 'Groups'),
-        'rule_groups': fields.Many2Many('ir.rule.group', 'user_rule_group_rel',
-            'user_id', 'rule_group_id', 'Rules',
-            domain="[('global', '<>', True)]"),
-        'language': fields.Selection('languages', 'Language'),
-        'timezone': fields.Selection('timezones', 'Timezone'),
-    }
+    name = fields.Char('Name', size=64, required=True, select=1)
+    login = fields.Char('Login', size=64, required=True)
+    password = fields.Char('Password', size=64)
+    signature = fields.Text('Signature', size=64)
+    #address_id = fields.Many2One('res.partner.address', 'Address')
+    active = fields.Boolean('Active')
+    action = fields.Many2One('ir.action', 'Home Action')
+    menu = fields.Many2One('ir.action', 'Menu Action')
+    groups = fields.Many2Many('res.group', 'res_group_user_rel',
+       'uid', 'gid', 'Groups')
+    rule_groups = fields.Many2Many('ir.rule.group', 'user_rule_group_rel',
+       'user_id', 'rule_group_id', 'Rules',
+       domain="[('global', '<>', True)]")
+    language = fields.Selection('languages', 'Language')
+    timezone = fields.Selection('timezones', 'Timezone')
     _sql_constraints = [
         ('login_key', 'UNIQUE (login)',
             'You can not have two users with the same login!')
@@ -209,12 +205,7 @@ User()
 
 
 class Group2(Group):
-
-    def __init__(self, pool):
-        super(Group2, self).__init__(pool)
-        if pool:
-            self._columns = copy.copy(self._columns)
-            self._columns['users'] = fields.many2many(
-                'res.user', 'res_group_user_rel', 'gid', 'uid', 'Users')
+    users = fields.many2many(
+        'res.user', 'res_group_user_rel', 'gid', 'uid', 'Users')
 
 Group2()
diff --git a/trytond/webdav/webdav.py b/trytond/webdav/webdav.py
index ac1b4dfe59..658919a1a9 100644
--- a/trytond/webdav/webdav.py
+++ b/trytond/webdav/webdav.py
@@ -10,14 +10,12 @@ class Directory(OSV):
     "Directory"
     _name = "webdav.directory"
     _description = __doc__
-    _columns = {
-        'name': fields.Char('Name', size=128, required=True, select=1),
-        'parent': fields.Many2One('webdav.directory', 'Parent',
-            ondelete='restrict'),
-        'childs': fields.One2Many('webdav.directory', 'parent', 'Childs'),
-        'model': fields.Many2One('ir.model', 'Model'),
-        'domain': fields.Char('Domain', size=250),
-    }
+    name = fields.Char('Name', size=128, required=True, select=1)
+    parent = fields.Many2One('webdav.directory', 'Parent',
+       ondelete='restrict')
+    childs = fields.One2Many('webdav.directory', 'parent', 'Childs')
+    model = fields.Many2One('ir.model', 'Model')
+    domain = fields.Char('Domain', size=250)
     _defaults = {
         'domain': lambda *a: '[]',
     }
diff --git a/trytond/workflow/workflow.py b/trytond/workflow/workflow.py
index c33a8b7d53..cdd00aaff2 100644
--- a/trytond/workflow/workflow.py
+++ b/trytond/workflow/workflow.py
@@ -12,13 +12,11 @@ class Workflow(OSV):
     _table = "wkf"
     _log_access = False
     _description = __doc__
-    _columns = {
-        'name': fields.Char('Name', size=64, required=True),
-        'osv': fields.Char('Resource Model', size=64, required=True),
-        'on_create': fields.Boolean('On Create'),
-        'activities': fields.One2Many('workflow.activity', 'workflow',
-            'Activities'),
-    }
+    name = fields.Char('Name', size=64, required=True)
+    osv = fields.Char('Resource Model', size=64, required=True)
+    on_create = fields.Boolean('On Create')
+    activities = fields.One2Many('workflow.activity', 'workflow',
+       'Activities')
     _defaults = {
         'on_create': lambda *a: True
     }
@@ -44,35 +42,33 @@ class WorkflowActivity(OSV):
     _table = "wkf_activity"
     _log_access = False
     _description = __doc__
-    _columns = {
-        'name': fields.Char('Name', size=64, required=True),
-        'workflow': fields.Many2One('workflow', 'Workflow', required=True,
-            select=1, ondelete='cascade'),
-        'split_mode': fields.Selection([
-            ('XOR', 'Xor'),
-            ('OR', 'Or'),
-            ('AND', 'And'),
-            ], 'Split Mode', size=3, required=True),
-        'join_mode': fields.Selection([
-            ('XOR', 'Xor'),
-            ('AND', 'And'),
-            ], 'Join Mode', size=3, required=True),
-        'kind': fields.Selection([
-            ('dummy', 'Dummy'),
-            ('function', 'Function'),
-            ('subflow', 'Subflow'),
-            ('stopall', 'Stop All'),
-            ], 'Kind', size=64, required=True),
-        'action': fields.Char('Action', size=64),
-        'flow_start': fields.Boolean('Flow Start'),
-        'flow_stop': fields.Boolean('Flow Stop'),
-        'subflow': fields.Many2One('workflow', 'Subflow'),
-        'signal_send': fields.Char('Signal (subflow.*)', size=32),
-        'out_transitions': fields.One2Many('workflow.transition', 'act_from',
-            'Outgoing transitions'),
-        'in_transitions': fields.One2Many('workflow.transition', 'act_to',
-            'Incoming transitions'),
-    }
+    name = fields.Char('Name', size=64, required=True)
+    workflow = fields.Many2One('workflow', 'Workflow', required=True,
+       select=1, ondelete='cascade')
+    split_mode = fields.Selection([
+       ('XOR', 'Xor'),
+       ('OR', 'Or'),
+       ('AND', 'And'),
+       ], 'Split Mode', size=3, required=True)
+    join_mode = fields.Selection([
+       ('XOR', 'Xor'),
+       ('AND', 'And'),
+       ], 'Join Mode', size=3, required=True)
+    kind = fields.Selection([
+       ('dummy', 'Dummy'),
+       ('function', 'Function'),
+       ('subflow', 'Subflow'),
+       ('stopall', 'Stop All'),
+       ], 'Kind', size=64, required=True)
+    action = fields.Char('Action', size=64)
+    flow_start = fields.Boolean('Flow Start')
+    flow_stop = fields.Boolean('Flow Stop')
+    subflow =  fields.Many2One('workflow', 'Subflow')
+    signal_send = fields.Char('Signal (subflow.*)', size=32)
+    out_transitions = fields.One2Many('workflow.transition', 'act_from',
+       'Outgoing transitions')
+    in_transitions = fields.One2Many('workflow.transition', 'act_to',
+       'Incoming transitions')
     _defaults = {
         'kind': lambda *a: 'dummy',
         'join_mode': lambda *a: 'XOR',
@@ -89,17 +85,15 @@ class WorkflowTransition(OSV):
     _log_access = False
     _rec_name = 'signal'
     _description = __doc__
-    _columns = {
-        'trigger_model': fields.Char('Trigger Type', size=128),
-        'trigger_expr_id': fields.Char('Trigger Expr ID', size=128),
-        'signal': fields.Char('Signal (button Name)', size=64),
-        'group': fields.Many2One('res.group', 'Group Required'),
-        'condition': fields.Char('Condition', required=True, size=128),
-        'act_from': fields.Many2One('workflow.activity', 'Source Activity',
-            required=True, select=1, ondelete='cascade'),
-        'act_to': fields.Many2One('workflow.activity', 'Destination Activity',
-            required=True, select=1, ondelete='cascade'),
-    }
+    trigger_model = fields.Char('Trigger Type', size=128)
+    trigger_expr_id = fields.Char('Trigger Expr ID', size=128)
+    signal = fields.Char('Signal (button Name)', size=64)
+    group = fields.Many2One('res.group', 'Group Required')
+    condition = fields.Char('Condition', required=True, size=128)
+    act_from = fields.Many2One('workflow.activity', 'Source Activity',
+       required=True, select=1, ondelete='cascade')
+    act_to = fields.Many2One('workflow.activity', 'Destination Activity',
+       required=True, select=1, ondelete='cascade')
     _defaults = {
         'condition': lambda *a: 'True',
     }
@@ -114,13 +108,11 @@ class WorkflowInstance(OSV):
     _rec_name = 'res_type'
     _log_access = False
     _description = __doc__
-    _columns = {
-        'workflow': fields.Many2One('workflow', 'Workflow', ondelete="restrict"),
-        'uid': fields.Integer('User ID'),
-        'res_id': fields.Integer('Resource ID'),
-        'res_type': fields.Char('Resource Model', size=64),
-        'state': fields.Char('State', size=32),
-    }
+    workflow = fields.Many2One('workflow', 'Workflow', ondelete="restrict")
+    uid = fields.Integer('User ID')
+    res_id = fields.Integer('Resource ID')
+    res_type = fields.Char('Resource Model', size=64)
+    state = fields.Char('State', size=32)
 
     def _auto_init(self, cursor, module_name):
         super(WorkflowInstance, self)._auto_init(cursor, module_name)
@@ -143,15 +135,13 @@ class WorkflowWorkitem(OSV):
     _log_access = False
     _rec_name = 'state'
     _description = __doc__
-    _columns = {
-        'activity': fields.Many2One('workflow.activity', 'Activity',
-            required=True, ondelete="cascade"),
-        'subflow': fields.Many2One('workflow.instance', 'Subflow',
-            ondelete="cascade"),
-        'instance': fields.Many2One('workflow.instance', 'Instance',
-            required=True, ondelete="cascade", select=1),
-        'state': fields.Char('State', size=64),
-    }
+    activity = fields.Many2One('workflow.activity', 'Activity',
+       required=True, ondelete="cascade")
+    subflow = fields.Many2One('workflow.instance', 'Subflow',
+       ondelete="cascade")
+    instance = fields.Many2One('workflow.instance', 'Instance',
+       required=True, ondelete="cascade", select=1)
+    state = fields.Char('State', size=64)
 
 WorkflowWorkitem()
 
@@ -162,14 +152,12 @@ class WorkflowTrigger(OSV):
     _name = "workflow.trigger"
     _log_access = False
     _description = __doc__
-    _columns = {
-        'res_id': fields.Integer('Resource ID', size=128),
-        'model': fields.Char('Model', size=128),
-        'instance': fields.Many2One('workflow.instance',
-            'Destination Instance', ondelete="cascade"),
-        'workitem': fields.Many2One('workflow.workitem', 'Workitem',
-            required=True, ondelete="cascade"),
-    }
+    res_id = fields.Integer('Resource ID', size=128)
+    model = fields.Char('Model', size=128)
+    instance = fields.Many2One('workflow.instance',
+       'Destination Instance', ondelete="cascade")
+    workitem = fields.Many2One('workflow.workitem', 'Workitem',
+       required=True, ondelete="cascade")
 
     def _auto_init(self, cursor, module_name):
         super(WorkflowTrigger, self)._auto_init(cursor, module_name)