Quickstart
Three minutes, no cloud account. The repo ships a runnable demo and a small real table.
On a real table (no setup)
The repo includes fixtures/taxi-nyc, a small Delta table written from public
NYC TLC
yellow-taxi data, partitioned by pickup date:
# date is the partition column: directory-level pruning, exact
delta-explain fixtures/taxi-nyc -w "pickup_date = '2024-01-03'"
# date prunes partitions, fare prunes on min/max stats within them
delta-explain fixtures/taxi-nyc -w "pickup_date = '2024-01-03' AND fare_amount > 50"
# a predicate that does NOT prune - and the tool tells you why
delta-explain fixtures/taxi-nyc -w "PULocationID = 132" --explain-why
That last command is the point of the tool: the pickup-zone column is not
clustered, so data skipping cannot help, and --explain-why says so with a fix.
See Why isn't it pruning?.
The guided tour
examples/quickstart/quickstart.sh walks five beats against the tables
committed in the repo, with no Docker and no cloud account: partition
pruning, data skipping, a predicate that degrades instead of failing, the CI
gate with its JSON, and a table feature the report declares. Its README
explains each beat:
examples/quickstart/quickstart.sh
It uses the delta-explain on your PATH, or DX_BIN=/path/to/binary.
Next
- Reading a report: what every line means.
- Gating pruning in CI: turn it into a build check.