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Coral reads engine settings from config.toml in the local state directory. See Local state for the default location and the CORAL_CONFIG_DIR override.

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Dependent joins

Dependent joins let Coral rewrite eligible SQL joins into dependent predicate pushdown, so join-key values from one side can be sent as filters to an HTTP-backed source. The default settings live under [engine.dependent_join]. 
[engine.dependent_join]
enabled = true
max_bindings = 500
max_resolver_rows = 10000
max_rows_per_binding = 1000
max_resolver_rows_per_binding = 1000
max_concurrency = 8
KeyTypeDefaultDescription
enabledbooleantrueEnables the dependent-join optimizer rule globally.
max_bindingsinteger500Maximum distinct join-key combinations Coral will push to an upstream API.
max_resolver_rowsinteger10000Maximum rows read from the key-supplying side before Coral falls back.
max_rows_per_bindinginteger1000Maximum rows accepted from one dependent upstream request.
max_resolver_rows_per_bindinginteger1000Maximum key-supplying rows allowed for one join-key combination.
max_concurrencyinteger8Concurrent upstream requests issued by one dependent join.
All numeric limits must be greater than zero.

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Per-source overrides

Use [engine.dependent_join.per_source.<source>] to override any dependent-join setting for one source. Unspecified keys inherit the global value. 
[engine.dependent_join]
enabled = false
max_concurrency = 8
max_bindings = 500

[engine.dependent_join.per_source.github]
enabled = true
max_concurrency = 4
max_bindings = 200

[engine.dependent_join.per_source.linear]
enabled = false
Per-source overrides use the installed source name, which is the SQL schema name before the table. In the example above, github applies to joins that read from tables such as github.pull_requests. Precedence is:
  1. per-source override
  2. global [engine.dependent_join] value
  3. Coral’s built-in default
Table-level overrides are not supported.