> ## Documentation Index
> Fetch the complete documentation index at: https://private-7c7dfe99-fix-nav-issues.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

> System table containing information about normal and aggregate functions.

# system.functions

<h2 id="description">
  Description
</h2>

Contains information about normal and aggregate functions.

<h2 id="columns">
  Columns
</h2>

* `name` ([String](/reference/data-types/index)) — The name of the function.
* `is_aggregate` ([UInt8](/reference/data-types/index)) — Whether the function is an aggregate function.
* `case_insensitive` ([UInt8](/reference/data-types/index)) — Whether the function name can be used case-insensitively.
* `alias_to` ([String](/reference/data-types/index)) — The original function name, if the function name is an alias.
* `create_query` ([String](/reference/data-types/index)) — Obsolete.
* `origin` ([Enum8('System' = 0, 'SQLUserDefined' = 1, 'ExecutableUserDefined' = 2, 'WasmUserDefined' = 3)](/reference/data-types/index)) — Obsolete.
* `description` ([String](/reference/data-types/index)) — A high-level description what the function does.
* `syntax` ([String](/reference/data-types/index)) — Signature of the function.
* `arguments` ([String](/reference/data-types/index)) — The function arguments.
* `parameters` ([String](/reference/data-types/index)) — The function parameters (only for aggregate function).
* `returned_value` ([String](/reference/data-types/index)) — What does the function return.
* `examples` ([String](/reference/data-types/index)) — Usage example.
* `introduced_in` ([String](/reference/data-types/index)) — ClickHouse version in which the function was first introduced.
* `categories` ([String](/reference/data-types/index)) — The category of the function.
* `deterministic` ([Nullable(UInt8)](/reference/data-types/index)) — Whether the function returns the same result for the same arguments. NULL when unknown (e.g. aggregate or user-defined functions).
* `higher_order` ([Nullable(UInt8)](/reference/data-types/index)) — Whether the function is higher-order — i.e. accepts at least one lambda expression as an argument (e.g. arrayMap, arrayFilter, mapApply). NULL when unknown.

<h2 id="example">
  Example
</h2>

```sql title="Query" theme={null}
 SELECT name, is_aggregate, deterministic, case_insensitive, alias_to FROM system.functions LIMIT 5;
```

```text title="Response" theme={null}
┌─name─────────────────────┬─is_aggregate─┬─deterministic─┬─case_insensitive─┬─alias_to─┐
│ BLAKE3                   │            0 │                1 │                0 │          │
│ sipHash128Reference      │            0 │                1 │                0 │          │
│ mapExtractKeyLike        │            0 │                1 │                0 │          │
│ sipHash128ReferenceKeyed │            0 │                1 │                0 │          │
│ mapPartialSort           │            0 │                1 │                0 │          │
└──────────────────────────┴──────────────┴──────────────────┴──────────────────┴──────────┘

5 rows in set. Elapsed: 0.002 sec.
```