alterFileFormat

Last updated: January 27, 2026

Modifies properties of an existing file format in Snowflake, including comment and format-specific options.

Note: This change type does not support automatic rollback.

Available attributes

Attribute	Type	Description	Required
`catalogName`	String	Name of the catalog (database) containing the file format	No
`schemaName`	String	Name of the schema containing the file format	No
`fileFormatName`	String	Name of the file format to alter	Yes
`ifExists`	Boolean	Only alter if the file format exists using `IF EXISTS`	No
`newComment`	String	New comment text to set*	No
`unsetComment`	Boolean	Remove the existing comment*	No

* newComment and unsetComment are mutually exclusive

formatTypeOptions attributes

Attribute	Type	Description	Required
`key`	String	Format-specific option name (e.g., `COMPRESSION`)	Yes
`value`	String	Option value	Yes

<?xml version="1.0" encoding="UTF-8"?>
<databaseChangeLog
        xmlns="http://www.liquibase.org/xml/ns/dbchangelog"
        xmlns:pro-snowflake="http://www.liquibase.org/xml/ns/pro-snowflake"
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        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/pro-snowflake
        http://www.liquibase.org/xml/ns/pro-snowflake/liquibase-pro-snowflake-latest.xsd">

    <!-- Alter file format options and comment -->
    <changeSet id="alter-file-format-options" author="examples">
        <pro-snowflake:alterFileFormat
                fileFormatName="CSV_FORMAT"
                ifExists="true"
                newComment="Updated CSV format with new compression">
            <pro-snowflake:formatTypeOptions>
                <pro-snowflake:entry key="COMPRESSION" value="DEFLATE"/>
                <pro-snowflake:entry key="SKIP_HEADER" value="2"/>
            </pro-snowflake:formatTypeOptions>
        </pro-snowflake:alterFileFormat>
    </changeSet>

    <!-- Alter file format to change only comment -->
    <changeSet id="alter-file-format-comment" author="examples">
        <pro-snowflake:alterFileFormat
                fileFormatName="JSON_FORMAT"
                newComment="Production JSON format"/>
    </changeSet>

    <!-- Unset comment from file format -->
    <changeSet id="alter-file-format-unset-comment" author="examples">
        <pro-snowflake:alterFileFormat
                fileFormatName="PARQUET_FORMAT"
                unsetComment="true"/>
    </changeSet>

</databaseChangeLog>

{
  "databaseChangeLog": [
    {
      "changeSet": {
        "id": "alter-file-format-options",
        "author": "examples",
        "changes": [
          {
            "alterFileFormat": {
              "fileFormatName": "CSV_FORMAT",
              "ifExists": true,
              "newComment": "Updated CSV format with new compression",
              "formatTypeOptions": {
                "entries": [
                  { "entry": { "key": "COMPRESSION", "value": "DEFLATE" } },
                  { "entry": { "key": "SKIP_HEADER", "value": "2" } }
                ]
              }
            }
          }
        ]
      }
    },
    {
      "changeSet": {
        "id": "alter-file-format-comment",
        "author": "examples",
        "changes": [
          {
            "alterFileFormat": {
              "fileFormatName": "JSON_FORMAT",
              "newComment": "Production JSON format"
            }
          }
        ]
      }
    },
    {
      "changeSet": {
        "id": "alter-file-format-unset-comment",
        "author": "examples",
        "changes": [
          {
            "alterFileFormat": {
              "fileFormatName": "PARQUET_FORMAT",
              "unsetComment": true
            }
          }
        ]
      }
    }
  ]
}

databaseChangeLog:
  # Alter file format options and comment
  - changeSet:
      id: alter-file-format-options
      author: examples
      changes:
        - alterFileFormat:
            fileFormatName: CSV_FORMAT
            ifExists: true
            newComment: Updated CSV format with new compression
            formatTypeOptions:
              entries:
                - entry:
                    key: COMPRESSION
                    value: DEFLATE
                - entry:
                    key: SKIP_HEADER
                    value: "2"

  # Alter file format to change only comment
  - changeSet:
      id: alter-file-format-comment
      author: examples
      changes:
        - alterFileFormat:
            fileFormatName: JSON_FORMAT
            newComment: Production JSON format

  # Unset comment from file format
  - changeSet:
      id: alter-file-format-unset-comment
      author: examples
      changes:
        - alterFileFormat:
            fileFormatName: PARQUET_FORMAT
            unsetComment: true

--liquibase formatted sql

--changeset examples:alter-file-format-options-and-comment
-- Alter file format options and comment
ALTER FILE FORMAT IF EXISTS PUBLIC.CSV_FORMAT SET
    COMPRESSION = 'DEFLATE'
    SKIP_HEADER = 2
    COMMENT = 'Updated CSV format with new compression';

--changeset examples:alter-file-format-to-change-only-comment
-- Alter file format to change only comment
ALTER FILE FORMAT PUBLIC.JSON_FORMAT SET
    COMMENT = 'Production JSON format';

--changeset examples:unset-comment-from-file-format
-- Unset comment from file format
ALTER FILE FORMAT PUBLIC.PARQUET_FORMAT UNSET COMMENT;

<?xml version="1.0" encoding="UTF-8"?>
<databaseChangeLog
        xmlns="http://www.liquibase.org/xml/ns/dbchangelog"
        xmlns:pro-snowflake="http://www.liquibase.org/xml/ns/pro-snowflake"
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        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/pro-snowflake
        http://www.liquibase.org/xml/ns/pro-snowflake/liquibase-pro-snowflake-latest.xsd">

    <!-- Alter file format options and comment -->
    <changeSet id="alter-file-format-options" author="examples">
        <pro-snowflake:alterFileFormat
                fileFormatName="CSV_FORMAT"
                ifExists="true"
                newComment="Updated CSV format with new compression">
            <pro-snowflake:formatTypeOptions>
                <pro-snowflake:entry key="COMPRESSION" value="DEFLATE"/>
                <pro-snowflake:entry key="SKIP_HEADER" value="2"/>
            </pro-snowflake:formatTypeOptions>
        </pro-snowflake:alterFileFormat>
    </changeSet>

    <!-- Alter file format to change only comment -->
    <changeSet id="alter-file-format-comment" author="examples">
        <pro-snowflake:alterFileFormat
                fileFormatName="JSON_FORMAT"
                newComment="Production JSON format"/>
    </changeSet>

    <!-- Unset comment from file format -->
    <changeSet id="alter-file-format-unset-comment" author="examples">
        <pro-snowflake:alterFileFormat
                fileFormatName="PARQUET_FORMAT"
                unsetComment="true"/>
    </changeSet>

</databaseChangeLog>

{
  "databaseChangeLog": [
    {
      "changeSet": {
        "id": "alter-file-format-options",
        "author": "examples",
        "changes": [
          {
            "alterFileFormat": {
              "fileFormatName": "CSV_FORMAT",
              "ifExists": true,
              "newComment": "Updated CSV format with new compression",
              "formatTypeOptions": {
                "entries": [
                  { "entry": { "key": "COMPRESSION", "value": "DEFLATE" } },
                  { "entry": { "key": "SKIP_HEADER", "value": "2" } }
                ]
              }
            }
          }
        ]
      }
    },
    {
      "changeSet": {
        "id": "alter-file-format-comment",
        "author": "examples",
        "changes": [
          {
            "alterFileFormat": {
              "fileFormatName": "JSON_FORMAT",
              "newComment": "Production JSON format"
            }
          }
        ]
      }
    },
    {
      "changeSet": {
        "id": "alter-file-format-unset-comment",
        "author": "examples",
        "changes": [
          {
            "alterFileFormat": {
              "fileFormatName": "PARQUET_FORMAT",
              "unsetComment": true
            }
          }
        ]
      }
    }
  ]
}

databaseChangeLog:
  # Alter file format options and comment
  - changeSet:
      id: alter-file-format-options
      author: examples
      changes:
        - alterFileFormat:
            fileFormatName: CSV_FORMAT
            ifExists: true
            newComment: Updated CSV format with new compression
            formatTypeOptions:
              entries:
                - entry:
                    key: COMPRESSION
                    value: DEFLATE
                - entry:
                    key: SKIP_HEADER
                    value: "2"

  # Alter file format to change only comment
  - changeSet:
      id: alter-file-format-comment
      author: examples
      changes:
        - alterFileFormat:
            fileFormatName: JSON_FORMAT
            newComment: Production JSON format

  # Unset comment from file format
  - changeSet:
      id: alter-file-format-unset-comment
      author: examples
      changes:
        - alterFileFormat:
            fileFormatName: PARQUET_FORMAT
            unsetComment: true

--liquibase formatted sql

--changeset examples:alter-file-format-options-and-comment
-- Alter file format options and comment
ALTER FILE FORMAT IF EXISTS PUBLIC.CSV_FORMAT SET
    COMPRESSION = 'DEFLATE'
    SKIP_HEADER = 2
    COMMENT = 'Updated CSV format with new compression';

--changeset examples:alter-file-format-to-change-only-comment
-- Alter file format to change only comment
ALTER FILE FORMAT PUBLIC.JSON_FORMAT SET
    COMMENT = 'Production JSON format';

--changeset examples:unset-comment-from-file-format
-- Unset comment from file format
ALTER FILE FORMAT PUBLIC.PARQUET_FORMAT UNSET COMMENT;

alterFileFormat

Available attributes

formatTypeOptions attributes

XML

JSON

YAML

SQL

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