HTTP interface for indexes
The HTTP API for indexes lets you create, delete, and list indexes
All indexes in ArangoDB have a unique identifier. It identifies an
index within a collection and is managed by ArangoDB. The full identifier
is prefixed with a collection name and a forward slash (
/) to identify an
index within a database.
For example, assume that the full index identifier is
demo/63563528, then the
URL of that index is as follows:
indexes attribute containing an array of all
index descriptions for the given collection. The same information is also
available in the
identifiers attribute as an object with the index identifiers
as object keys.
Return information about all indexes
curl --header 'accept: application/json' --dump - http://localhost:8529/_api/index?collection=products
The result is an object describing the index. It has at least the following attributes:
id: the identifier of the index
type: the index type
All other attributes are type-dependent. For example, some indexes provide
sparse flags, whereas others don’t. Some indexes also provide
a selectivity estimate in the
selectivityEstimate attribute of the result.
curl --header 'accept: application/json' --dump - http://localhost:8529/_api/index/products/0
Creates a new index in the collection
an object containing the index details.
The type of the index to be created must specified in the type attribute of the index details. Depending on the index type, additional other attributes may need to specified in the request in order to create the index.
Indexes require the to be indexed attribute(s) in the fields attribute of the index details. Depending on the index type, a single attribute or multiple attributes can be indexed. In the latter case, an array of strings is expected.
. character denotes sub-attributes in attribute paths. Attributes with
. in their name cannot be indexed. Attributes with the name
cannot be indexed either, neither as a top-level attribute nor as a sub-attribute.
Optionally, an index name may be specified as a string in the name attribute. Index names have the same restrictions as collection names. If no value is specified, one will be auto-generated.
Persistent indexes (including vertex-centric indexes) can be created as unique
or non-unique variants. Uniqueness can be controlled by specifying the
unique option for the index definition. Setting it to
true creates a
unique index. Setting it to
false or omitting the
unique attribute creates a
Persistent indexes can optionally be created in a sparse
variant. A sparse index will be created if the sparse attribute in
the index details is set to
true. Sparse indexes do not index documents
for which any of the index attributes is either not set or is
The optional deduplicate attribute is supported by persistent array indexes.
It controls whether inserting duplicate index values
from the same document into a unique array index will lead to a unique constraint
error or not. The default value is
true, so only a single instance of each
non-unique index value will be inserted into the index per document. Trying to
insert a value into the index that already exists in the index always fails,
regardless of the value of this attribute.
The optional estimates attribute is supported by persistent indexes.
This attribute controls whether index selectivity estimates are
maintained for the index. Not maintaining index selectivity estimates can have
a slightly positive impact on write performance.
The downside of turning off index selectivity estimates will be that
the query optimizer will not be able to determine the usefulness of different
competing indexes in AQL queries when there are multiple candidate indexes to
estimates attribute is optional and defaults to
true if not set. It will
have no effect on indexes other than persistent indexes.
The optional attribute cacheEnabled is supported by indexes of type
persistent. This attribute controls whether an extra in-memory hash cache is
created for the index. The hash cache can be used to speed up index lookups.
The cache can only be used for queries that look up all index attributes via
an equality lookup (
==). The hash cache cannot be used for range scans,
partial lookups or sorting.
The cache will be populated lazily upon reading data from the index. Writing data
into the collection or updating existing data will invalidate entries in the
cache. The cache may have a negative effect on performance in case index values
are updated more often than they are read.
The maximum size of cache entries that can be stored is currently 4 MB, i.e.
the cumulated size of all index entries for any index lookup value must be
less than 4 MB. This limitation is there to avoid storing the index entries
of “super nodes” in the cache.
cacheEnabled defaults to
false and should only be used for indexes that
are known to benefit from an extra layer of caching.
The optional attribute inBackground can be set to
true to create the index
in the background, which will not write-lock the underlying collection for
as long as if the index is built in the foreground.
curl -X DELETE --header 'accept: application/json' --dump - http://localhost:8529/_api/index/products/82788