ALTER ICEBERG TABLE … CONVERT TO MANAGED

Converts an Apache Iceberg™ table that uses an external Iceberg catalog into a table that uses Snowflake as the catalog (a Snowflake-managed Iceberg table).

The converted table supports both read and write operations, and Snowflake handles all life-cycle maintenance, such as compaction, for the table. For more information, see Before and after table conversion.

See also:

CREATE ICEBERG TABLE , DROP ICEBERG TABLE , SHOW ICEBERG TABLES , DESCRIBE ICEBERG TABLE

Syntax

ALTER ICEBERG TABLE [ IF EXISTS ] <table_name> CONVERT TO MANAGED
  [ BASE_LOCATION = '<directory_for_table_files>' ]
  [ STORAGE_SERIALIZATION_POLICY = { COMPATIBLE | OPTIMIZED } ]
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Parameters

table_name

Identifier for the table to convert.

If the identifier contains spaces or special characters, the entire string must be enclosed in double quotes. Identifiers enclosed in double quotes are also case-sensitive.

For more information, see Identifier requirements.

[ BASE_LOCATION = 'directory_for_table_files' ]

The path to a directory where Snowflake can write data and metadata files for the table. Specify a relative path from the table’s EXTERNAL_VOLUME location. For more information, see Data and metadata directories.

You must specify a value for this property if the original CREATE ICEBERG TABLE statement did not allow or include a BASE_LOCATION.

This directory can’t be changed after you convert a table.

STORAGE_SERIALIZATION_POLICY = { COMPATIBLE | OPTIMIZED }

Specifies the storage serialization policy for the table. If not specified during conversion, the table inherits the value set at the schema, database, or account level. If the value isn’t specified at any level, the table uses the default value.

You can’t change the value of this parameter after you convert a table.

  • COMPATIBLE: Snowflake performs encoding and compression that ensures interoperability with third-party compute engines.

  • OPTIMIZED: Snowflake performs encoding and compression that ensures the best table performance within Snowflake.

Default: OPTIMIZED

Access control requirements

A role used to execute this SQL command must have the following privileges at a minimum:

Privilege

Object

Notes

OWNERSHIP

Iceberg table

OWNERSHIP is a special privilege on an object that is automatically granted to the role that created the object, but can also be transferred using the GRANT OWNERSHIP command to a different role by the owning role (or any role with the MANAGE GRANTS privilege).

USAGE

External volume

USAGE

Catalog integration

Note that operating on any object in a schema also requires the USAGE privilege on the parent database and schema.

For instructions on creating a custom role with a specified set of privileges, see Creating custom roles.

For general information about roles and privilege grants for performing SQL actions on securable objects, see Overview of Access Control.

Usage notes

  • Only the table owner (that is, the role with the OWNERSHIP privilege on the table) or higher can execute this command.

  • Regarding metadata:

    Attention

    Customers should ensure that no personal data (other than for a User object), sensitive data, export-controlled data, or other regulated data is entered as metadata when using the Snowflake service. For more information, see Metadata fields in Snowflake.

Examples

The following example uses the ALTER ICEBERG TABLE … CONVERT TO MANAGED statement to convert a table that Snowflake doesn’t manage into a table that uses Snowflake as the Iceberg catalog.

ALTER ICEBERG TABLE myTable CONVERT TO MANAGED
  BASE_LOCATION = 'my/relative/path/from/external_volume';
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