--- title: "Acuan index model" version: 6.0 locale: id source: https://docs.djangoproject.com/id/6.0/ref/models/indexes/ canonical: https://djangodocs.dev/id/6.0/ref/models/indexes/ --- # Acuan index model Index classes ease creating database indexes. They can be added using the [`Meta.indexes`](/id/6.0/ref/models/options/#django.db.models.Options.indexes) option. This document explains the API references of [`Index`](#django.db.models.Index) which includes the [index options](#index-options). > **Mengacu pengindeksan siap-pakai** > > Pengindeksan ditentukan dalam `django.db.models.indexes`, tetapi untuk kenyamanan mereka diimpor kedalam [`django.db.models`](/id/6.0/topics/db/models/#module-django.db.models). Kebiasaan standar untuk digunakan `from django.db import models` dan mengacu ke pengindeksan sebagai `models.`. ## Pilihan `Index` #### `class Index(*expressions, fields=(), name=None, db_tablespace=None, opclasses=(), condition=None, include=None)` Membuat sebuah index (B-tree) dalam basisdata. ### `expressions` #### `Index.expressions` Positional argument `*expressions` allows creating functional indexes on expressions and database functions. Sebagai contoh: ``` Index(Lower("title").desc(), "pub_date", name="lower_title_date_idx") ``` creates an index on the lowercased value of the `title` field in descending order and the `pub_date` field in the default ascending order. Another example: ``` Index(F("height") * F("weight"), Round("weight"), name="calc_idx") ``` creates an index on the result of multiplying fields `height` and `weight` and the `weight` rounded to the nearest integer. [`Index.name`](#django.db.models.Index.name) is required when using `*expressions`. > **Restrictions on Oracle** > > Oracle requires functions referenced in an index to be marked as > `DETERMINISTIC`. Django doesn't validate this but Oracle will error. This > means that functions such as > [`Random()`](/id/6.0/ref/models/database-functions/#django.db.models.functions.Random) aren't accepted. > **Restrictions on PostgreSQL** > > PostgreSQL requires functions and operators referenced in an index to be > marked as `IMMUTABLE`. Django doesn't validate this but PostgreSQL will > error. This means that functions such as > [`Concat()`](/id/6.0/ref/models/database-functions/#django.db.models.functions.Concat) aren't accepted. > **MySQL dan MariaDB** > > Functional indexes are ignored with MySQL \< 8.0.13 and MariaDB as neither > supports them. ### `fields` #### `Index.fields` Sebuah list atau tuple dari nama dari bidang-bidang dimana indeks diharapkan. By default, indexes are created with an ascending order for each column. To define an index with a descending order for a column, add a hyphen before the field's name. For example `Index(fields=['headline', '-pub_date'])` would create SQL with `(headline, pub_date DESC)`. > **MariaDB** > > Index ordering isn't supported on MariaDB \< 10.8. In that case, a > descending index is created as a normal index. ### `name` #### `Index.name` The name of the index. If `name` isn't provided Django will auto-generate a name. For compatibility with different databases, index names cannot be longer than 30 characters and shouldn't start with a number (0-9) or underscore (\_). > **Partial indexes in abstract base classes** > > You must always specify a unique name for an index. As such, you > cannot normally specify a partial index on an abstract base class, since > the [`Meta.indexes`](/id/6.0/ref/models/options/#django.db.models.Options.indexes) option is > inherited by subclasses, with exactly the same values for the attributes > (including `name`) each time. To work around name collisions, part of the > name may contain `'%(app_label)s'` and `'%(class)s'`, which are > replaced, respectively, by the lowercased app label and class name of the > concrete model. For example `Index(fields=['title'], > name='%(app_label)s_%(class)s_title_index')`. ### `db_tablespace` #### `Index.db_tablespace` The name of the [database tablespace](/id/6.0/topics/db/tablespaces/) to use for this index. For single field indexes, if `db_tablespace` isn't provided, the index is created in the `db_tablespace` of the field. If [`Field.db_tablespace`](/id/6.0/ref/models/fields/#django.db.models.Field.db_tablespace) isn't specified (or if the index uses multiple fields), the index is created in tablespace specified in the [`db_tablespace`](/id/6.0/ref/models/options/#django.db.models.Options.db_tablespace) option inside the model's `class Meta`. If neither of those tablespaces are set, the index is created in the same tablespace as the table. > **See also** > > Untuk daftar dari index khusus-PostgreSQL, lihat [`django.contrib.postgres.indexes`](/id/6.0/ref/contrib/postgres/indexes/#module-django.contrib.postgres.indexes). ### `opclasses` #### `Index.opclasses` The names of the [PostgreSQL operator classes](https://www.postgresql.org/docs/current/indexes-opclass.html) to use for this index. If you require a custom operator class, you must provide one for each field in the index. For example, `GinIndex(name='json_index', fields=['jsonfield'], opclasses=['jsonb_path_ops'])` creates a gin index on `jsonfield` using `jsonb_path_ops`. `opclasses` are ignored for databases besides PostgreSQL. [`Index.name`](#django.db.models.Index.name) is required when using `opclasses`. ### `condition` #### `Index.condition` If the table is very large and your queries mostly target a subset of rows, it may be useful to restrict an index to that subset. Specify a condition as a [`Q`](/id/6.0/ref/models/querysets/#django.db.models.Q). For example, `condition=Q(pages__gt=400)` indexes records with more than 400 pages. [`Index.name`](#django.db.models.Index.name) is required when using `condition`. > **Restrictions on PostgreSQL** > > PostgreSQL requires functions referenced in the condition to be marked as > IMMUTABLE. Django doesn't validate this but PostgreSQL will error. This > means that functions such as [Fungsi tanggal](/id/6.0/ref/models/database-functions/#date-functions) and > [`Concat`](/id/6.0/ref/models/database-functions/#django.db.models.functions.Concat) aren't accepted. If you store > dates in [`DateTimeField`](/id/6.0/ref/models/fields/#django.db.models.DateTimeField), comparison to > [`datetime`](https://docs.python.org/3/library/datetime.html#datetime.datetime) objects may require the `tzinfo` argument > to be provided because otherwise the comparison could result in a mutable > function due to the casting Django does for [lookups](/id/6.0/ref/models/querysets/#field-lookups). > **Restrictions on SQLite** > > SQLite [imposes restrictions](https://www.sqlite.org/partialindex.html) > on how a partial index can be constructed. > **Oracle** > > Oracle does not support partial indexes. Instead, partial indexes can be > emulated by using functional indexes together with > [`Case`](/id/6.0/ref/models/conditional-expressions/#django.db.models.expressions.Case) expressions. > **MySQL dan MariaDB** > > The `condition` argument is ignored with MySQL and MariaDB as neither > supports conditional indexes. ### `include` #### `Index.include` A list or tuple of the names of the fields to be included in the covering index as non-key columns. This allows index-only scans to be used for queries that select only included fields ([`include`](#django.db.models.Index.include)) and filter only by indexed fields ([`fields`](#django.db.models.Index.fields)). Sebagai contoh: ``` Index(name="covering_index", fields=["headline"], include=["pub_date"]) ``` will allow filtering on `headline`, also selecting `pub_date`, while fetching data only from the index. Using `include` will produce a smaller index than using a multiple column index but with the drawback that non-key columns can not be used for sorting or filtering. `include` is ignored for databases besides PostgreSQL. [`Index.name`](#django.db.models.Index.name) is required when using `include`. See the PostgreSQL documentation for more details about [covering indexes](https://www.postgresql.org/docs/current/indexes-index-only-scans.html). > **Restrictions on PostgreSQL** > > PostgreSQL supports covering B-Tree and [`GiST indexes`](/id/6.0/ref/contrib/postgres/indexes/#django.contrib.postgres.indexes.GistIndex). PostgreSQL 14+ also supports > covering [`SP-GiST indexes`](/id/6.0/ref/contrib/postgres/indexes/#django.contrib.postgres.indexes.SpGistIndex).