roller

    CREATE TYPE school_type AS ENUM ('college', 'high_school');
    CREATE TABLE schools (
      id SERIAL PRIMARY KEY,
      type school_type,
      unique (id, type)
    );
    CREATE TABLE colleges (
      id INTEGER NOT NULL,
      type school_type default 'college',
      check (type='college'),
      foreign key (id, type) references school(id, type)
    );

    foreign key (id, 'college') references school(id, type)

  Because table partitioning is less general than table inheritance, it
  is hoped that it will be easier to reason about properties of
  partitions, and therefore that this will serve as a better foundation
  for a variety of possible optimizations, including query planner
  optimizations.

    { "mrow": [
        { "mi": "x" },
        { "mo": "=" },
        { "mfrac": [
            { "mrow": [
                { "mo": "-" },
                { "mi": "b" },
                { "mo": "±" },
                { "sqrt": {
                    { "mrow": [
                        {"mi": "b"},
                        {"msup": { "mi": 2 }},
                        {"mo": "-"},
                        {"mi", "4ac"}
                    ]}
                }}
            },
            { "mrow": [
                {"mi": "2a"}
            ]}
        ]}
    }