column_id

BIGINT

Primary key

The column ID.

If the initial Parquet file contains the field_id value, it is used as the column_id value. The ID is not updated until the column is deleted.

column_id values must be unique.

begin_snapshot

BIGINT

Foreign key, NOT NULL

The snapshot associated with creating the column, from the pga_snapshot metadata table.

end_snapshot

BIGINT

Foreign key

The snapshot associated with deleting the column, from the pga_snapshot metadata table.

If the value is NULL, the column is not deleted.

table_id

BIGINT

Foreign key, NOT NULL

The ID of the analytical table that contains the column, from the pga_table metadata table.

column_order

BIGINT

NOT NULL

The sequence number of the column.

column_order values must be unique within the analytical table, but the ordered sequence can have gaps.

column_name

VARCHAR

NOT NULL

The column name, for example, my_column.

column_name values are not UNIQUE because pgpro_metastore does not delete the metadata of columns. Deleted columns are associated with end_snapshot values to indicate that these columns can no longer be used.

This allows you to create a new column with the same name as a previously deleted column.

column_type

VARCHAR

NOT NULL

The column type corresponding to one of the supported pgpro_metastore data types.

initial_default

VARCHAR

-

The initial column value after its creation, for example, after executing the ALTER TABLE command.

It can be NULL.

default_value

VARCHAR

-

The default column value used in upsert operations.

It can be NULL.

nulls_allowed

BOOLEAN

-

Specifies whether the column can contain NULL values.

is_uniq

BOOLEAN

-

Specifies whether the column can contain repeating values for different rows.