27.7. pga_folder Metadata Table #

This metadata table contains information about shared directories used for storing Parquet files. For example, you can use these directories as a source of Parquet files for the add_files ETL operation.

Column Name

Column Type

Constraint

Description

folder_id

BIGINT

Primary key

The shared directory ID assigned by increasing the next_catalog_id value of the pga_snapshot metadata table.

begin_snapshot

BIGINT

Foreign key, NOT NULL

The snapshot from the pga_snapshot metadata table associated with the shared directory creation date and time.

end_snapshot

BIGINT

Foreign key

The snapshot from the pga_snapshot metadata table associated with the shared directory deletion date and time.

If the value is NULL, the shared directory is not deleted.

path

VARCHAR

NOT NULL

The path to the shared directory relative to the root storage directory.

The absolute path is generated by concatenating the uri value of the pga_storage metadata table and the path value of the pga_folder metadata table.

folder_name

VARCHAR

NOT NULL

The shared directory name, for example, my_directory.

folder_name values are not UNIQUE because pgpro_metastore does not delete metadata of shared directories. Deleted directories are rather associated with end_snapshot values to indicate that these directories can no longer be used.

If folder_name values were UNIQUE, you would not be able to create a new shared directory with the same name as a previously deleted directory.

storage_id

BIGINT

Foreign key, NOT NULL

The ID of the storage from the pga_storage metadata table where the shared directory is created.