Druid answers OLAP queries in under a second from time-partitioned segments. DbSchema connects to the Broker over the Avatica JDBC protocol and diagrams the datasources behind those queries — columns, types, and structure on one canvas.
TIME_FLOOR and approximate aggregations with completionTrusted by teams at
In Druid, each datasource's shape is buried in JSON — a dimensionsSpec here,
a metricsSpec there, rollup changing what actually lands. Analysts see only
the query side and guess at the rest.
DbSchema introspects the Broker's catalog and draws the result: real datasources, real columns, real types — the model as it exists, not as the spec intended.
The analytics model — drawn, queried, and documented from one desktop app.
Arrange datasources into annotated layouts per pipeline or domain, so the analytics estate reads as a map instead of a flat list of names.
Compose TIME_FLOOR() buckets and APPROX_COUNT_DISTINCT() aggregations with datasource and column completion, then hand the verified query to your BI tool.
Publish documentation that captures column names, types, and the relationships modeled in your ingestion specs — readable without ever opening a spec file.
The design model is a local file, so a datasource can be drafted, discussed, and corrected on the canvas before the first segment is ever built.
Lay out columns and types for a new datasource before writing its ingestion spec.
A wrong column caught in review costs a redraw — not another ingestion cycle.
Commit the model next to your ingestion JSON and diff schema changes over time.
Sample fresh rows in the data explorer and compare against what the spec promised.
Druid speaks JDBC through Apache Calcite Avatica: load the Avatica standalone JAR — see the
Druid JDBC driver page — into DbSchema's driver
manager and use the remote driver class org.apache.calcite.avatica.remote.Driver.
The URL points at the Broker node:
jdbc:avatica:remote:url=http://broker:8082/druid/v2/sql/avatica/, with
8082 as the default Broker port. On secured clusters, switch the scheme to
https and enter credentials in the connection dialog.
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Teams working with Apache Druid often use these engines too. Explore dedicated guides and JDBC setup for each.