reference/sql/ALTER-DATABASE.html.md.erb

---
title: ALTER DATABASE
---

Changes the attributes of a database.

## Synopsis<a id="alterrole__section2"></a>

``` pre
ALTER DATABASE name SET parameter { TO | + } { value | DEFAULT } 

ALTER DATABASE name RESET parameter 
```

## Description<a id="desc"></a>

`ALTER DATABASE` changes the attributes of a HAWQ database.

`SET` and `RESET` *parameter* changes the session default for a configuration parameter for a HAWQ database. Whenever a new session is subsequently started in that database, the specified value becomes the session default value. The database-specific default overrides whatever setting is present in the server configuration file (`hawq-site.xml`). Only the database owner or a superuser can change the session defaults for a database. Certain parameters cannot be set this way, or can only be set by a superuser.

## Parameters<a id="alterrole__section4"></a>

 *name*   
The name of the database whose attributes are to be altered.

**Note:** HAWQ reserves the database "hcatalog" for system use. You cannot connect to or alter the system "hcatalog" database.

 *parameter*   
Set this database's session default for the specified configuration parameter to the given value. If value is `DEFAULT` or if `RESET` is used, the database-specific setting is removed, so the system-wide default setting will be inherited in new sessions. Use `RESET ALL` to clear all database-specific settings. See [About Server Configuration Parameters](../guc/guc_config.html#topic1) for information about user-settable configuration parameters.

## Notes<a id="notes"></a>

It is also possible to set a configuration parameter session default for a specific role (user) rather than to a database. Role-specific settings override database-specific ones if there is a conflict. See [ALTER ROLE](ALTER-ROLE.html).

## Examples<a id="examples"></a>

To set the default schema search path for the `mydatabase` database:

``` pre
ALTER DATABASE mydatabase SET search_path TO myschema, 
public, pg_catalog;
```

## Compatibility<a id="compat"></a>

The `ALTER DATABASE` statement is a HAWQ extension.

## See Also<a id="see"></a>

[CREATE DATABASE](CREATE-DATABASE.html#topic1), [DROP DATABASE](DROP-DATABASE.html#topic1), [SET](SET.html)