Logical relation functions produce relations from a function call in FROM. Spiral uses them for metadata surfaces today and will use the same registry for extension packages that produce logical relation expansions.

Use the built-in metadata table function to list what is registered:

SELECT *
FROM spql.meta.table_functions();

The result includes:

Filter to public table functions:

SELECT function_set, parameters, summary
FROM spql.meta.table_functions()
WHERE visibility = 'public'
ORDER BY function_set;

The current built-in surface includes metadata functions and registered logical extension table functions. Source functions such as local file readers are a separate catalog category and are not listed by spql.meta.table_functions().

List source functions separately:

SELECT function_set, parameters, summary
FROM spql.meta.source_functions()
WHERE visibility = 'public'
ORDER BY function_set;

This surface lists static registration metadata only. It does not include output schemas, because source-function schemas can depend on concrete arguments and may require source resolution.

List SpiralDB tables in a project:

SELECT project_id, dataset, table_name, table_id, escaped
FROM spiraldb.meta.tables(project_id => 'my_project')
ORDER BY dataset, table_name;

Filter to one dataset or table name:

SELECT *
FROM spiraldb.meta.tables(
  project_id => 'my_project',
  dataset => 'my_dataset',
  table_name => 'events'
);

This is a SpiralDB-specific metadata surface. It does not expose a full SQL information_schema yet. The relation_name column is a display-oriented spiraldb.<project>.<dataset>.<table> relation name. The escaped column quotes project ids, datasets, and table names when needed, so it can be used in a follow-up query:

SELECT *
FROM spiraldb.my_project.my_dataset.events
LIMIT 10;

The SQL REPL also starts with the SpiralDB catalog selected. Use a current project and dataset to make single-part names resolve into SpiralDB:

USE PROJECT damp-unit-976647;
USE DATASET default;
 
SELECT *
FROM "cell-painting-cpg0001"
LIMIT 10;

List registered scalar functions:

SELECT function_set, overload, parameters, summary
FROM spql.meta.scalar_functions()
WHERE visibility = 'public'
ORDER BY function_set, overload;

List registered aggregate functions:

SELECT function_set, parameters, summary
FROM spql.meta.aggregate_functions()
ORDER BY function_set;

List registered extension dtypes:

SELECT *
FROM spql.meta.extension_types();

The result includes:

Filter to dtypes whose storage shape or semantic contract may change:

SELECT id, summary
FROM spql.meta.extension_types()
WHERE stability = 'unstable'
ORDER BY id;

List registered COPY TO formats:

SELECT format, aliases
FROM spql.meta.copy_formats()
ORDER BY format;