cube-js/cube · error

Explain is not supported

Error message

Explain is not supported

What it means

The same EQ-graph converter panics on LogicalPlan::Explain: EXPLAIN statements are not supported in the logical-plan-to-graph translation, so an Explain plan reaching the converter aborts instead of producing a graph.

Source

Thrown at rust/cubesql/cubesql/src/compile/rewrite/converter.rs:814

                ]))
            }
            LogicalPlan::Limit(limit) => {
                let skip = add_data_node!(self, limit.skip, LimitSkip);
                let fetch = add_data_node!(self, limit.fetch, LimitFetch);
                let input =
                    self.add_logical_plan_replace_params(limit.input.as_ref(), query_params, ctx)?;
                self.graph
                    .add(LogicalPlanLanguage::Limit([skip, fetch, input]))
            }
            LogicalPlan::Values(values) => {
                let values = add_data_node!(self, values.values, ValuesValues);
                self.graph.add(LogicalPlanLanguage::Values([values]))
            }
            LogicalPlan::CreateExternalTable { .. } => {
                panic!("CreateExternalTable is not supported");
            }
            LogicalPlan::Explain { .. } => {
                panic!("Explain is not supported");
            }
            LogicalPlan::Analyze { .. } => {
                panic!("Analyze is not supported");
            }
            // TODO
            LogicalPlan::Extension(ext) => {
                panic!("Unsupported extension node: {}", ext.node.schema());
            }
            LogicalPlan::Distinct(distinct) => {
                let input = self.add_logical_plan_replace_params(
                    distinct.input.as_ref(),
                    query_params,
                    ctx,
                )?;
                self.graph.add(LogicalPlanLanguage::Distinct([input]))
            }
            // TODO: Support all
            _ => unimplemented!("Unsupported node type: {:?}", plan),

View on GitHub (pinned to 7d981676b3)

Solutions

1. Remove the EXPLAIN prefix and run the underlying query; use Cube's own query-inspection/logging for plan details.
2. Intercept EXPLAIN statements at the SQL gateway before they reach the converter.
3. Guard code that converts plans with a variant check for Explain/Analyze.

Example fix

// before
EXPLAIN SELECT count(*) FROM orders;
// after
SELECT count(*) FROM orders;

When it happens

Trigger: Sending EXPLAIN <query> (or EXPLAIN ANALYZE, which similarly panics) through CubeSQL so its plan converts via add_logical_plan_replace_params.

Common situations: Debugging queries by prefixing EXPLAIN out of habit from Postgres workflows, ORM/BI tools that auto-generate EXPLAIN for query analysis.

Related errors

• CreateExternalTable is not supported
• This query doesnt have a plan, because it already has values
• Should be rewritten with UtcTimestamp function
• Analyze is not supported
• Unsupported extension node: {}

AI-assisted analysis of cube-js/cube@7d981676b3 (2026-09-02). Data as JSON: /api/errors/36aace92b9848594. Report an issue: GitHub.