trino-config-properties.md

paths	**/*Config.java **/*SessionProperties.java

Trino — configuration and session properties

Naming:

• Config property names use dashes, e.g. hive.max-partitions-per-scan.
• Session property names use snake_case, e.g. max_partitions_per_scan.

Adding a property:

• Every @Config setter gets an @ConfigDescription("…").
• Every session property registration includes a description.
• Credentials and other secrets get @ConfigSecuritySensitive so values are redacted in logs and info endpoints.

Renaming a config:

• Add a @Deprecated setter with @LegacyConfig(value = "old.name", replacedBy = "new.name") that writes to the same field as the new @Config("new.name") setter. The old name keeps working as a backward-compatible alias.

Removing a config:

• Add the current name and any @LegacyConfig names to @DefunctConfig on the class so startup fails loudly if the config is still set.
• Remove the matching session property from SystemSessionProperties.java (or the connector's session-properties class) if one exists.

Testing a new config:

• Add a matching TestMyConfig using Airlift's ConfigAssertions — see existing Test*Config classes for the testDefaults() / testExplicitPropertyMappings() pattern.

Other conventions:

• Validation annotations (@NotNull, @Min, @MinDuration, etc.) go on setters, not fields.
• Don't store the config object as a field — read values in the constructor and keep those instead.