system.functions
A read-only descriptive catalog of functions. It includes syntax and behavior text for registered descriptive entries; some callable legacy functions do not have a row.
Use the function reference for the complete documented public interface. A missing catalog row is not proof that the function is unavailable.
Columns
| Name | Meaning |
|---|---|
| name | Function name. |
| is_aggregate | Whether this row describes an aggregate overload. |
| case_insensitive | Whether name matching ignores case. |
| alias_to | Alias target, when present. |
| create_query | Creation definition, when applicable. |
| origin | Function origin metadata. |
| description | Behavior summary. |
| syntax | Calling syntax. |
| arguments | Argument descriptions. |
| parameters | Parameter metadata. |
| returned_value | Result description. |
| examples | Example SQL text. |
| introduced_in | Available version metadata. |
| categories | Descriptive categories. |
| deterministic | Nullable determinism flag. |
| higher_order | Nullable higher-order-function flag. |
Example
sql
SELECT name, is_aggregate, syntax
FROM system.functions
WHERE name = 'count'
FORMAT csv;text
"count",1,"count(), count(*), count(value), count(DISTINCT value)"The relation is server-provided and can be read before USE. Always qualify it with system. See functions.