The following are PostgreSQL specific indexes
available from the django.contrib.postgres.indexes
module.
BloomIndex
¶Creates a bloom index.
To use this index access you need to activate the bloom extension on
PostgreSQL. You can install it using the
BloomExtension
migration
operation.
Provide an integer number of bits from 1 to 4096 to the length
parameter to specify the length of each index entry. PostgreSQL's default
is 80.
The columns
argument takes a tuple or list of up to 32 values that are
integer number of bits from 1 to 4095.
BrinIndex
¶Creates a BRIN index.
Set the autosummarize
parameter to True
to enable automatic
summarization to be performed by autovacuum.
The pages_per_range
argument takes a positive integer.
BTreeIndex
¶Creates a B-Tree index.
Provide an integer value from 10 to 100 to the fillfactor parameter to tune how packed the index pages will be. PostgreSQL's default is 90.
Provide a boolean value to the deduplicate_items parameter to control whether deduplication is enabled. PostgreSQL enables deduplication by default.
The deduplicate_items
parameter was added.
GinIndex
¶Creates a gin index.
To use this index on data types not in the built-in operator classes,
you need to activate the btree_gin extension on
PostgreSQL. You can install it using the
BtreeGinExtension
migration
operation.
Set the fastupdate
parameter to False
to disable the GIN Fast
Update Technique that's enabled by default in PostgreSQL.
Provide an integer number of kilobytes to the gin_pending_list_limit
parameter to tune the maximum size of the GIN pending list which is used
when fastupdate
is enabled.
GistIndex
¶Creates a GiST index. These indexes are
automatically created on spatial fields with spatial_index=True
. They're
also useful on other types, such as
HStoreField
or the range
fields.
To use this index on data types not in the built-in gist operator classes,
you need to activate the btree_gist extension on PostgreSQL.
You can install it using the
BtreeGistExtension
migration
operation.
Set the buffering
parameter to True
or False
to manually enable
or disable buffering build of the index.
Provide an integer value from 10 to 100 to the fillfactor parameter to tune how packed the index pages will be. PostgreSQL's default is 90.
HashIndex
¶Creates a hash index.
Provide an integer value from 10 to 100 to the fillfactor parameter to tune how packed the index pages will be. PostgreSQL's default is 90.
SpGistIndex
¶Creates an SP-GiST index.
Provide an integer value from 10 to 100 to the fillfactor parameter to tune how packed the index pages will be. PostgreSQL's default is 90.
OpClass()
expressions¶An OpClass()
expression represents the expression
with a custom
operator class that can be used to define functional indexes, functional
unique constraints, or exclusion constraints. To use it, you need to add
'django.contrib.postgres'
in your INSTALLED_APPS
. Set the
name
parameter to the name of the operator class.
For example:
Index(
OpClass(Lower("username"), name="varchar_pattern_ops"),
name="lower_username_idx",
)
creates an index on Lower('username')
using varchar_pattern_ops
.
UniqueConstraint(
OpClass(Upper("description"), name="text_pattern_ops"),
name="upper_description_unique",
)
creates a unique constraint on Upper('description')
using
text_pattern_ops
.
ExclusionConstraint(
name="exclude_overlapping_ops",
expressions=[
(OpClass("circle", name="circle_ops"), RangeOperators.OVERLAPS),
],
)
creates an exclusion constraint on circle
using circle_ops
.
Jan 15, 2024