Overview

You can use this Snap to output a list of tables in a database. The Snap will connect to the database, read its metadata, and output a document for each table found in the database. The table names are output in a topological order so that tables with the fewest dependencies are output first. In other words, if table A has a foreign key reference to table B, then table B will be output before A. The ordering is intended to ease the process of replicating a group of tables from one database to another.

Replicating a Subset of Tables

The output of the Table List Snap can be directly used to replicate an entire database. However, if you are only interested in a subset of tables, you can use a Filter Snap to select the table names you are interested in as well as the tables that they reference. For example, given the following diamond-shaped table graph where A depends on B and C and they both depend on D:

       A
               / \
              B   C
               \ /
                D 

The Table List will output the following documents:

name=D; dependents=[A, B, C, D]
name=C; dependents=[A, C]
name=B; dependents=[A, B]
name=A; dependents=[A]

So, if you wanted to copy just table 'A' and its dependencies, you can add a Filter Snap with the following expression:

 $.dependents.indexOf('A') != -1

The filter will then remove any extra tables that happen to be in the schema.

• Read-type Snap
• Works in Ultra Tasks. However, we recommend that you not use this Snap in an Ultra Pipeline

Prerequisites

You must have minimum permissions on the database to execute Snowflake Snaps. To understand if you already have them, you must retrieve the current set of permissions. The following commands enable you to retrieve those permissions:

SHOW GRANTS ON DATABASE <database_name>
        SHOW GRANTS ON SCHEMA <schema_name>
        SHOW GRANTS TO USER <user_name>

grant usage on database <database_name> to role <role_name>;
         grant usage on schema <database_name>.<schema_name>;

Known Issues

Because of performance issues, all Snowflake Snaps now ignore the Cancel queued queries when pipeline is stopped or if it fails option for Manage Queued Queries, even when selected. Snaps behave as though the default Continue to execute queued queries when the Pipeline is stopped or if it fails option were selected.

Snap views

Snap settings