Truncate large JSONs in psql

truncate_large_fields.sql

CREATE OR REPLACE FUNCTION truncate_large_fields(
    json_data jsonb,
    max_length int DEFAULT 100
) RETURNS jsonb AS $$
DECLARE
    key text;
    value jsonb;
    result jsonb := '{}';
BEGIN
    FOR key, value IN SELECT * FROM jsonb_each(json_data)
    LOOP
        IF jsonb_typeof(value) = 'string' AND length(value::text) > max_length THEN
            result := result || jsonb_build_object(key, substr(value::text, 1, max_length) || '...');
        ELSIF jsonb_typeof(value) = 'object' THEN
            result := result || jsonb_build_object(key, truncate_large_fields(value, max_length));
        ELSIF jsonb_typeof(value) = 'array' THEN
            result := result || jsonb_build_object(key, (
                SELECT jsonb_agg(truncate_large_fields(element, max_length))
                FROM jsonb_array_elements(value) AS element
            ));
        ELSE
            result := result || jsonb_build_object(key, value);
        END IF;
    END LOOP;
    RETURN result;
END;
$$ LANGUAGE plpgsql;