Orca API Reference

The Orca platform is a real-time computing framework built on DolphinDB's streaming infrastructure. It provides declarative APIs that abstract away low-level complexities (e.g., parallel scheduling, subscription mechanisms, and resource management), allowing developers to focus on business logic.

Category Interface Description
Definition createStreamGraph Create a StreamGraph object
StreamGraph::setConfigMap Configure private stream tables and subscriptions in the graph
StreamGraph::source / keyedSource / latestKeyedSource / haSource / haKeyedSource Define an input source stream table
StreamGraph::sourceByName Retrieve an Orca public stream table
DStream::anomalyDetectionEngine Define an anomaly detection engine
DStream::asofJoinEngine Define an asof join engine
DStream::crossSectionalEngine Define a cross-sectional engine
DStream::cryptoOrderBookEngine Define a real-time crypto order book engine
DStream::dailyTimeSeriesEngine Define a daily time-series engine
DStream::dualOwnershipReactiveStateEngine Define a dual-ownership reactive state engine
DStream::narrowReactiveStateEngine Define a reactive state engine that outputs narrow tables
DStream::pricingEngine Define a pricing engine
DStream::reactiveStateEngine Define a reactive state engine
DStream::reactiveStatelessEngine Define a reactive stateless engine
DStream::ruleEngine Define a rule engine
DStream::sessionWindowEngine Define a session window engine
DStream::timeBucketEngine Define a time series aggregation engine with custom bucket sizes
DStream::timeSeriesEngine Define a time series aggregation engine
DStream::equalJoinEngine Define an equi join engine
DStream::leftSemiJoinEngine Define a left semi join engine
DStream::lookupJoinEngine Define a lookup join engine
DStream::snapshotJoinEngine Define a snapshot join engine
DStream::windowJoinEngine Define a window join engine
DStream::buffer / keyedBuffer / latestKeyedBuffer Define a stream table for immediate output
DStream::sink / keyedSink / latestKeySink / haSink / haKeyedSink Define an output stream table
DStream::map Define data transformation logic
DStream::fork Branch the stream graph
DStream::parallelize Set the parallelism of the stream graph
DStream::sync Aggregate the results of upstream parallel tasks
DStream::setEngineName Set name for a streaming engine
DStream::getOutputSchema Retrieve the table schema for downstream definition
Graph Management StreamGraph::submit Submit the stream graph to start execution
getStreamGraph Retrieve the stream graph object
dropStreamGraph Destroy the stream graph
purgeStreamGraphRecords Delete stream graph records
Stream Table Operations appendOrcaStreamTable Insert data into stream tables
useOrcaStreamTable Operate on the specified stream table from a remote node
select * from orca_table. or select * from .orca_table. Query a stream table
Streaming Engine Operations warmupOrcaStreamEngine Warm up streaming engine to improve initial computation performance
useOrcaStreamEngine Operate on the specified streaming engine from a remote node
Status Monitoring getStreamGraphInfo / getStreamGraphMeta Retrieve stream graph metadata
getOrcaStreamTableMeta Retrieve stream table metadata
getOrcaStreamEngineMeta Retrieve streaming engine metadata
getOrcaStreamTaskSubscriptionMeta Retrieve subscription metadata
getOrcaStateMachineEventTaskStatus Get state machine task status
StreamGraph::toGraphviz / str Output the topology structure
Checkpoint Management setOrcaCheckpointConfig Configure checkpoint parameters
getOrcaCheckpointConfig View checkpoint configuration
getOrcaCheckpointJobInfo View checkpoint job execution info
getOrcaCheckpointSubjobInfo View checkpoint subjob execution info