Comment on page
Step 2 in the execution pipeline for many bulk read endpoints.
Many bulk read endpoints support an optional grouping parameter, using which results can be grouped together on some attribute. Common grouping attributes include:
- 2.Collection: Group by the collection of the node represented by an entity in the result set.
- 3.Type: Group by the type (vertex or edge) of node represented by an entity in the result set.
- 4.Event: Group by the type (created/updated/deleted) of event that the entity in a result set represents.
It is not necessary that all of the above grouping attributes are available for all endpoints. It depends on the core structure of the data requested.
If a grouping attribute is specified, an additional set of sub-parameters can be optionally specified that determine how the entries within a group are arranged. These are:
- 1.Group Sort: Sorts entries within a group by a specific attribute. The attribute choice depends on the specific endpoint. See API docs for more details.
- 2.Group Slice: Skip and/or limit entries within a group, post group-sort.
- 3.Aggregation (Count): Rather than return an entity list within a group, return their count (group-wise totals). If this sub-parameter is specified, the other sub-parameters are ignored.
There is a special case of aggregation, wherein counts are requested, but the grouping attribute is absent. In this case, the API returns the total count of ALL entities, rather than group-wise totals. In this case, the upper level sorting and slicing parameters are ignored.
Grouping clauses are applied within the DB query that is used to fetch intermediate results.