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

…riate 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
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commit 281114d2095608c93a00df2fc55a72f7cd5c2fcf 1 parent d10f976
@jbronn jbronn authored
Showing with 54 additions and 0 deletions.
  1. +39 −0 django/db/backends/postgresql/creation.py
  2. +15 −0 docs/ref/databases.txt
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39 django/db/backends/postgresql/creation.py
@@ -34,3 +34,42 @@ def sql_table_creation_suffix(self):
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
View
15 docs/ref/databases.txt
@@ -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
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