New Features¶ ↑

• The timed_queue and sharded_timed_queue connection pools (the default on Ruby 3.2+) now implement a num_waiting method, which will return now many threads or fibers are waiting to checkout a connection. This can be used for metrics on how loaded the connection pool is, which can help provide information on whether the connection pool max size should be modified.

• A class_table_inheritance_constraint_validations plugin has been added, which will allow subclasses using the class_table_inheritance plugin to respect constraint validations for all of the class’s tables.

• On PostgreSQL 18+, primary key and unique constraints now support a :without_overlaps option to use WITHOUT OVERLAPS, turning the constraint into an exclusion constraint on the last column.

• On PostgreSQL 18+, foreign keys now support a :period option to use PERIOD, which makes it so the final column in the constraint must be covered in the referenced table (potentially covered by a combination of rows).

• On PostgreSQL 15+, unique constraints now support a :nulls_not_distinct option, to use NULLS NOT DISTINCT, which will treat NULL values as separate values when determining uniqueness.

• On PostgreSQL 11+, primary key, unique, and exclude constraints now support an :include option to used INCLUDE, which includes additional columns in the related index, to increase opportunities for index-only scans.

• On PostgreSQL 9.2+, check constraints now support a :no_inherit option to prevent inheritance of the constraint.

• In addition to null: false to specify NOT NULL for columns, you can now specify not_null: true, and you can use a hash value for the :not_null option to provide constraint-specific options. On PostgreSQL 18+, you can provide a :name option inside the hash to name the related NOT NULL constraint, which allows for altering the constraint and dropping the constraint by name. You can also provide the :no_inherit option in the hash to prevent inheritance of the constraint.