> ## Documentation Index
> Fetch the complete documentation index at: https://clickhouse.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.

> Documentation for creating temporary tables

# CREATE TEMPORARY TABLE

<h2 id="temporary-table-support">
  Temporary table support
</h2>

<Note>
  Please note that temporary tables are not replicated. As a result, there is no guarantee that data inserted into a temporary table will be available in other replicas. The primary use case where temporary tables can be useful is for querying or joining small external datasets during a single session.
</Note>

ClickHouse supports temporary tables which have the following characteristics:

* Temporary tables disappear when the session ends, including if the connection is lost.
* A temporary table uses the Memory table engine when engine is not specified and it may use any table engine except Replicated and `KeeperMap` engines.
* The DB can't be specified for a temporary table. It is created outside of databases.
* Impossible to create a temporary table with distributed DDL query on all cluster servers (by using `ON CLUSTER`): this table exists only in the current session.
* If a temporary table has the same name as another one and a query specifies the table name without specifying the DB, the temporary table will be used.
* For distributed query processing, temporary tables with Memory engine used in a query are passed to remote servers.

<h2 id="syntax">
  Syntax
</h2>

To create a temporary table, use the following syntax:

```sql theme={null}
CREATE [OR REPLACE] TEMPORARY TABLE [IF NOT EXISTS] table_name
(
    name1 [type1] [DEFAULT|MATERIALIZED|ALIAS expr1],
    name2 [type2] [DEFAULT|MATERIALIZED|ALIAS expr2],
    ...
) [ENGINE = engine]
```

In most cases, temporary tables are not created manually, but when using external data for a query, or for distributed `(GLOBAL) IN`. For more information, see the appropriate sections

It's possible to use tables with [ENGINE = Memory](/docs/reference/engines/table-engines/special/memory) instead of temporary tables.