Tags
3 minute read
Introduction
Snowflake tags allow you to categorize and manage Snowflake objects by associating custom metadata with them. These tags support governance, cost tracking, and data lineage by enabling organizations to label resources with business-relevant information.
The Snowflake emulator supports tags, allowing you to apply these tags to the local Snowflake tables, views, and databases using the same commands and syntax as the Snowflake service. The following operations are supported:
Getting started
This guide is designed for users new to tagging in Snowflake and assumes basic knowledge of SQL and Snowflake. Start your Snowflake emulator and connect to it using an SQL client to execute the queries below.
The following sections guide you through an example of creating a database, adding a tag, and using the tag to track metadata in Snowflake.
Create a Database
The following SQL snippet demonstrates how to create a database named tag_test_db.
CREATE DATABASE IF NOT EXISTS tag_test_db;
The expected output is:
+--------------------------------------------+
| status |
|--------------------------------------------|
| Database TAG_TEST_DB successfully created. |
+--------------------------------------------+
0 Row(s) produced. Time Elapsed: 0.163s
Create a Tag
To create a tag, use the CREATE TAG statement. The following example demonstrates how to create a tag named tag1.
CREATE TAG tag1;
The expected output is:
+--------------------------------+
| ?COLUMN? |
|--------------------------------|
| Tag TAG1 successfully created. |
+--------------------------------+
0 Row(s) produced. Time Elapsed: 0.057s
Assign Tag to Database
To assign a tag to a database, use the ALTER DATABASE statement. The following example demonstrates how to assign the tag tag1 with the value 'test 123' to the tag_test_db database.
ALTER DATABASE tag_test_db SET TAG tag1 = 'test 123';
The expected output is:
+----------------------------------+
| ?column? |
|----------------------------------|
| Statement executed successfully. |
+----------------------------------+
0 Row(s) produced. Time Elapsed: 0.026s
Query Tag Value
To retrieve the value of a tag assigned to a database, use the SELECT SYSTEM$GET_TAG statement. The following example demonstrates how to query the value of tag1 assigned to the tag_test_db database.
SELECT SYSTEM$GET_TAG('tag1', 'tag_test_db', 'database');
The expected output is:
+----------------+
| SYSTEM$GET_TAG |
|----------------|
| test 123 |
+----------------+
1 Row(s) produced. Time Elapsed: 0.565s
Query Tag References
To view all references of a tag within a database, use the INFORMATION_SCHEMA.TAG_REFERENCES function. The following example demonstrates how to query the tag_test_db database for references to the tag1 tag.
SELECT *
FROM TABLE(tag_test_db.INFORMATION_SCHEMA.TAG_REFERENCES('tag_test_db', 'database'));
The expected output is:
+--------------+------------+----------+-----------+----------+-----------------+---------------+-------------+----------+-------------+
| TAG_DATABASE | TAG_SCHEMA | TAG_NAME | TAG_VALUE | LEVEL | OBJECT_DATABASE | OBJECT_SCHEMA | OBJECT_NAME | DOMAIN | COLUMN_NAME |
|--------------+------------+----------+-----------+----------+-----------------+---------------+-------------+----------+-------------|
| TAG_TEST_DB | PUBLIC | TAG1 | test 123 | DATABASE | NULL | NULL | TAG_TEST_DB | DATABASE | NULL |
+--------------+------------+----------+-----------+----------+-----------------+---------------+-------------+----------+-------------+
1 Row(s) produced. Time Elapsed: 0.528s