mirror of https://gitee.com/bigwinds/arangodb
21 lines
904 B
Markdown
21 lines
904 B
Markdown
Index {#GlossaryIndex}
|
|
======================
|
|
|
|
@GE{Index}: Indexes are used to allow fast access to documents. For
|
|
each collection there is always the primary index which is a hash
|
|
index for the document key (`_key` attribute). This index cannot be
|
|
dropped or changed.
|
|
|
|
Edge collections will also have an automatically created edges index,
|
|
which cannot be modified. This index provides quick access to documents
|
|
via the `_from` and `_to` attributes.
|
|
|
|
Most user-land indexes can be created by defining the names of the
|
|
attributes which should be indexed. Some index types allow indexing
|
|
just one attribute (e.g. fulltext index) whereas other index types
|
|
allow indexing multiple attributes.
|
|
|
|
Indexing system attributes such as `_id`, `_key`, `_from`, and `_to`
|
|
in user-defined indexes is not supported by any index type. Manually
|
|
creating an index that relies on any of these attributes is unsupported.
|