SQL WITH clause → inlines CTE filters into main query descriptor. 3 parser tests + 5 integration tests.
Worker middleware that injects row-level filters and strips column-level projections based on JWT. Example in examples/rbac-middleware.ts.
TCP server implementing pg wire v3 Simple Query protocol. Connect with psql, Tableau, Metabase, Grafana, dbt. 17 tests. src/pg-wire/.
addColumn(name, dtype, default) and dropColumn(name) — no data rewrite. Works on MaterializedExecutor, same pattern for Lance manifests. 5 tests.
Fan out writes by partition key to separate MasterDOs. Each DO handles its own CAS loop — no contention across partitions. Bio-cell model: more write pressure → more cells.
One-command project scaffold: generates wrangler.toml + src/worker.ts. Idempotent. Prints next steps.
Tree merge when fragment count exceeds threshold (default 50). Leaf Fragment DOs scan → reducer Fragment DOs merge groups of 25 → QueryDO merges final set. Keeps QueryDO memory bounded at any scale. reduceRpc on Fragment DO, hierarchicalReduce on Query DO. Explain output shows hierarchicalReduction and reducerTiers.
df.materializeAs("table_name") executes stage, writes results to a named table, returns new DataFrame for next stage. TypeScript is the DAG scheduler — chain stages through the executor's write path. 2 tests.
Build on materializeAs(): automatic intermediate table naming, cleanup after pipeline completion, lineage tracking via AppendOptions.metadata. TypeScript orchestrates the DAG — no Spark/YARN needed.