Materialize/misc/mzexplore

Copyright Materialize, Inc. and contributors. All rights reserved.

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Use of this software is governed by the Business Source License

included in the LICENSE file at the root of this repository.

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As of the Change Date specified in that file, in accordance with

the Business Source License, use of this software will be governed

by the Apache License, Version 2.0.

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mzexplore — tools for analyzing query plans

bin/mzexplore can extract plans from environments running Materialize. By running:

mzexplore extract plans ... \
          --explainee-type catalog_item \
          --with arity --with humanized_exprs --with join_impls \
          --format json \
          --stage optimized_plan

you can extract JSON files corresponding to the optimized MIR plan of a catalog item.

This directory contains jq scripts for extracting information from these JSON outputs.

• filters.jq: finds all predicates used in filters and returns a list, sorted by number of occurrences descending

• leftjoins.jq: finds unreduced left joins (particularly shaped unions of antijoins and an inner join)

• defs.jq: utility functions

Note that the ASTs we produce in JSON are quite deeply nested, so you can't use stock jq. As of 2024-03-12, there is a PR open to jq to allow you to specify unbounded depth on the command-line, i.e., --depth 0.

If you have multiple JSON files you'd like to analyze together, you can run:

find ~/mz-support/tmpfs/ -name \*.json |
  xargs jq --slurp --depth 0 -f filters.jq