38.1. pga_snapshot #

This metadata table contains information about snapshots.

Column Name

Column Type

Constraint

Description

snapshot_id

BIGINT

Primary key

The snapshot ID.

It is referenced by most metadata tables. The value increases by 1 for each created snapshot.

snapshot_time

TIMESTAMP

NOT NULL

The snapshot creation date and time.

schema_version

BIGINT

NOT NULL

The metadata catalog version.

The value increases by 1 each time the catalog metadata changes, for example, when a new analytical table is created.

This allows caching the catalog metadata.

next_catalog_id

BIGINT

NOT NULL

The ID assigned to the next metadata catalog object.

The value increases by 1 each time a catalog object is created, for example, when a new analytical table is created.

next_file_id

BIGINT

NOT NULL

The ID assigned to the next Parquet file.

The value increases by 1 each time a Parquet file is created or deleted.

is_visible

BOOLEAN

NOT NULL

Specifies whether metadata catalog objects associated with the snapshot are visible.

When an stored procedure, such as metastore.add_table, creates multiple catalog objects associated with the same snapshot, the is_visible value is set to false. Catalog objects become visible only after the operation completes successfully and the is_visible value is set to true.

You can use the is_visible value to temporarily hide a catalog object without deleting it and then make it visible again later.