Query Capabilities#

Dash Platform allows applications to retrieve data in a structured and deterministic manner. Clients query the latest committed state of identities, data contracts, documents, and other Platform data similar to traditional databases while retaining decentralized trust benefits.

Querying the State#

Queries operate on the finalized data stored within Platform’s state tree. Responses reflect the most recently committed block and do not include pending or historical intermediate changes.

This means:

  • Query results are consistent across nodes

  • Clients do not need to process blockchain history

  • Data retrieval is deterministic and efficient

Note

Queries return the current finalized state, not the sequence of events that created it.

Deterministic Results#

All queries produce deterministic results. The same query executed on two honest and up-to-date Platform nodes will always produce the same result. This ensures consistent application behavior regardless of which node provides the response.

Data Proofs#

Queries can return locally verifiable cryptographic proofs, allowing clients to verify response accuracy without trusting the responding node.

Two types of proofs exist:

Proof Type

Purpose

Inclusion Proof

Confirms that specific data exists and has not been modified

Non-Inclusion Proof

Confirms that specific data does not exist (useful for uniqueness checks such as usernames)

Proofs are especially valuable for:

  • Light clients

  • Browser-based and serverless environments

  • Trust-minimized applications

Indexed Queries#

Dash Platform requires queries to use indexes defined in the data contract for the relevant document type. If a field is not indexed, it cannot be used for filtering or sorting.

System fields are recognized by the query engine without being declared as normal schema properties. $id is implicitly queryable as the primary key. Other system fields like $ownerId, $createdAt, $updatedAt, and $transferredAt are built-in field names, but document queries still need to match an appropriate contract index. Querying and sorting on indexed fields also follows compound-index prefix and range/orderBy rules - see the query syntax reference for details.

Benefits of indexed querying include:

  • Predictable performance

  • Consistent execution across nodes

Important

Indexes should be planned during contract design since there are limited index update options for already registered contracts.