Commit 281114d2 authored by Justin Bronn's avatar Justin Bronn
Browse files

[1.1.X] Fixed #12234 -- Create additional indexes that use the appropriate... 

[1.1.X] Fixed #12234 -- Create additional indexes that use the appropriate operation class for PostgreSQL `varchar` and `text` columns when `db_index=True`.

Backport of r11912 from trunk.


git-svn-id: http://code.djangoproject.com/svn/django/branches/releases/1.1.X@11913 bcc190cf-cafb-0310-a4f2-bffc1f526a37
parent d10f9766

django/db/backends/postgresql/creation.py

+39 −0
Original line number Diff line number Diff line
@@ -34,3 +34,42 @@ class DatabaseCreation(BaseDatabaseCreation): 
        if settings.TEST_DATABASE_CHARSET:

            return "WITH ENCODING '%s'" % settings.TEST_DATABASE_CHARSET

        return ''



    def sql_indexes_for_field(self, model, f, style):

        if f.db_index and not f.unique:

            qn = self.connection.ops.quote_name

            db_table = model._meta.db_table

            tablespace = f.db_tablespace or model._meta.db_tablespace

            if tablespace:

                sql = self.connection.ops.tablespace_sql(tablespace)

                if sql:

                    tablespace_sql = ' ' + sql

                else:

                    tablespace_sql = ''

            else:

                tablespace_sql = ''



            def get_index_sql(index_name, opclass=''):

                return (style.SQL_KEYWORD('CREATE INDEX') + ' ' +

                        style.SQL_TABLE(qn(index_name)) + ' ' +

                        style.SQL_KEYWORD('ON') + ' ' +

                        style.SQL_TABLE(qn(db_table)) + ' ' +

                        "(%s%s)" % (style.SQL_FIELD(qn(f.column)), opclass) +

                        "%s;" % tablespace_sql)



            output = [get_index_sql('%s_%s' % (db_table, f.column))]



            # Fields with database column types of `varchar` and `text` need

            # a second index that specifies their operator class, which is

            # needed when performing correct LIKE queries outside the

            # C locale. See #12234.

            db_type = f.db_type()

            if db_type.startswith('varchar'):

                output.append(get_index_sql('%s_%s_like' % (db_table, f.column),

                                            ' varchar_pattern_ops'))

            elif db_type.startswith('text'):

                output.append(get_index_sql('%s_%s_like' % (db_table, f.column),

                                            ' text_pattern_ops'))

        else:

            output = []

        return output

docs/ref/databases.txt

+15 −0
Original line number Diff line number Diff line
@@ -80,6 +80,21 @@ You should also audit your existing code for any instances of this behavior 
before enabling this feature. It's faster, but it provides less automatic

protection for multi-call operations.



Indexes for ``varchar`` and ``text`` columns

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

.. versionadded:: 1.1.2



When specifying ``db_index=True`` on your model fields, Django typically

outputs a single ``CREATE INDEX`` statement.  However, if the database type

for the field is either ``varchar`` or ``text`` (e.g., used by ``CharField``,

``FileField``, and ``TextField``), then Django will create

an additional index that uses an appropriate `PostgreSQL operator class`_

for the column.  The extra index is necessary to correctly perfrom

lookups that use the ``LIKE`` operator in their SQL, as is done with the

``contains`` and ``startswith`` lookup types.



.. _PostgreSQL operator class: http://www.postgresql.org/docs/8.4/static/indexes-opclass.html



.. _mysql-notes:



MySQL notes