markUnused

Note: This is a Liquibase Pro Change Type, so you need a Liquibase Pro License Key to use it.

The markUnused Change Type is an Oracle-specific Change Type that marks a column as unused. The markUnused Change Type helps to avoid database slowdowns caused by dropping a populated column.

Uses

You can typically use the markUnused Change Type to mark columns as unused rather than dropping them immediately, which allows you to decide the best time to drop those columns.

Run `markUnused`

To run this Change Type, follow these steps:

Add the Change Type to your changeset, as shown in the examples on this page.
Specify any required attributes. Use the table on this page to see which ones your database requires.
Deploy your changeset by running the update command:

liquibase update

Available attributes

Name	Description	Required for	Supports
`catalogName`	Name of the catalog		all
`columnName`	Name of the column	all	all
`schemaName`	Name of the schema		all
`tableName`	Name of the table	all	all

Examples

--liquibase formatted sql

--changeset liquibase-docs:markUnused-example
ALTER  TABLE  cat.person  SET  UNUSED  COLUMN  id;

databaseChangeLog:
-  changeSet:
    id:  markUnused-example
    author:  liquibase-docs
    changes:
    -  markUnused:
        catalogName:  cat
        columnName:  id
        schemaName:  public
        tableName:  person

{
    "databaseChangeLog": [
        {
            "changeSet": {
                "id": "markUnused-example",
                "author": "liquibase-docs",
                "changes": [
                    {
                        "markUnused": {
                            "catalogName": "cat",
                            "columnName": "id",
                            "schemaName": "public",
                            "tableName": "person"
                        }
                    }
                ]
            }
        }
    ]
}

<databaseChangeLog
    xmlns="http://www.liquibase.org/xml/ns/dbchangelog"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:ext="http://www.liquibase.org/xml/ns/dbchangelog-ext"
    xmlns:pro="http://www.liquibase.org/xml/ns/pro"
    xsi:schemaLocation="http://www.liquibase.org/xml/ns/dbchangelog
        http://www.liquibase.org/xml/ns/dbchangelog/dbchangelog-latest.xsd
        http://www.liquibase.org/xml/ns/dbchangelog-ext
        http://www.liquibase.org/xml/ns/dbchangelog/dbchangelog-ext.xsd
        http://www.liquibase.org/xml/ns/pro
        http://www.liquibase.org/xml/ns/pro/liquibase-pro-latest.xsd">

    <changeSet  author="liquibase-docs"  id="markUnused-example">
        <pro:markUnused  catalogName="cat"
            columnName="id"
            schemaName="public"
            tableName="person"/>
    </changeSet>

</databaseChangeLog>

Database support