SQL Query Management

Cancelling Active Sessions Retrieve the running session list and terminate the target statement using its unique identifier.

SHOW FULL PROCESSLIST;
KILL QUERY <process_identifier>;

Alternatively, invoke the management REST endpoint directly:

curl -X POST -u "<username>:<password>" http://<backend_host>:9050/rest/v2/manager/query/kill/<query_id>

Configuring Dynamic Timestamp Defaults The standard NOW() function is unsupported as a static default value. Instead, utilize CURRENT_TIMESTAMP. When defining tables, assign it explicitly with precision specifications:

CREATE TABLE metric_logs (
  record_id INT PRIMARY KEY,
  payload STRING REPLACE NOT NULL,
  aggregation_key BIGINT SUM DEFAULT '1',
  event_time DATETIME(6) DEFAULT CURRENT_TIMESTAMP(6) ON UPDATE CURRENT_TIMESTAMP(6)
) DISTRIBUTED BY HASH(record_id);

Verifying Software Release Inspect the compiled version through multiple diagnostic paths:

1. Execute SHOW BACKENDS; to view cluster nodes and their software labels.
2. Run SHOW VARIABLES LIKE '%version_comment%'; within the SQL interface.
3. Invoke the binary directly from the command line: <doris_home>/be/lib/doris_be -v

Schema & Data Handling

External JDBC Catalog Connectivity Establish links to relational databases by explicitly declaring both the logical catalog name and the target database namespace in the connection string:

jdbc:mysql://<ip_address>:3306/<logical_catalog>.<target_database>

Integrated Analytics Pipelines For machine learning workloads resembling Apache Spark ML workflows, leverage the official connector library to export datasets into Spark clusters. Once ingested, standard MLlib modules can execute feature engineering and model training. Reference the connector documentation for dependency setup and configuration parameters.

Materialized View Schema Evolution Asynchronous materialized views in version 2.1.0 do not natively handle structural alterations. To adjust the underlying schema, construct a replacement view with the required columns and metrics, then apply a rename operation to swap it with the existing instance. This approach maintains query continuity without downtime.

Architecture & Deployment

Tablet Distribution Calculation The aggregate tablet count per table is derived from three primary parameters:

Total Tablets = Partition Count × Bucket Allocation Per Partition × Replication Factor

Network Initialization Failures Encountering NoRouteToHostException during service bootstrapping typically indicates two root causes:

1. Host-level firewall rules are actively filtering internal ports.
2. Underlying network infrastructure prevents direct routing between cluster nodes. Verify port accessibility and routing tables across all Backend (BE) and Frontend (FE) hosts.

Frontend Leader Selection Mechanism High availability for the Coordinator layer relies on an embedded consensus protocol within BDBJE. The selection logic mirrors distributed voting schemes akin to Paxos, ensuring a single active leader maintains state consistency.

Ecosystem Compatibility

The platform supports a broad range of visualization and business intelligence frontends. Proven integrations include:

• Open-source frameworks: Apache Superset, DataEase, Datart
• Enterprise solutions: SmartBI, Microsoft Power BI, Tableau, FineBI

Connection protocols generally follow standard ODBC/JDBC standards for seamless dashboard rendering.