14.1. Creating a Storage (metastore.add_storage) #
Before creating an S3 storage, create a simple secret. You can create only one S3 storage.
Required privileges: Postgres Pro AXE administrator only. For a full list of stored procedures and privileges, refer to Section 12.1.
Execute the following command on the Postgres Pro AXE server:
SELECT metastore.add_storage('storage_name', 'root_directory_URI', 'temporary_directory_URI') ON CONFLICT DO NOTHING;
Where:
storage_name: The unique storage name.root_directory_URI: The URI of the root directory of the storage.temporary_directory_URI: The URI of the temporary storage directory for Parquet files created by themetastore.copy_tablestored procedure. This directory must exist before storage creation.
Local storages have simple URIs (e.g., file:///home/j.doe/workspace/axe/).
S3 storages have URIs with more complicated structures and parsing (e.g., s3://premdb/team01.csv?versionId=w_B5qT8s5MkiT09.IRHay0lW.PycsHTS). These URIs are generated using third-party libraries.
Postgres Pro AXE performs the following actions:
Checks input parameters and user privileges.
Ensures that there is enough free space for the storage. By default, 10 GB is required.
Ensures that the specified directories exist.
Creates a new entry in the
pga_storagemetadata table.
Example 14.1. Executing the metastore.add_storage Stored Procedure (Local Storage)
SELECT metastore.add_storage('local_storage_example', 'file:///tmp/local_storage_example/', 'file:///tmp/local_storage_example/tmp_dir/') ON CONFLICT DO NOTHING;
Example 14.2. Executing the metastore.add_storage Stored Procedure (S3 Storage)
SELECT metastore.add_storage('s3_storage_example', 's3://demo/s3_storage_example/','s3://demo/s3_storage_example/tmp/') ON CONFLICT DO NOTHING;
For an S3 storage connection scenario, refer to Section 30.2.