27.9. pga_data_file Metadata Table #

This metadata table contains information about Parquet files.

Column Name

Column Type

Constraint

Description

data_file_id

BIGINT

Primary key

The Parquet file ID assigned by increasing the next_file_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 Parquet file creation date and time.

end_snapshot

BIGINT

Foreign key

The snapshot from the pga_snapshot metadata table associated with the Parquet file deletion date and time.

If the value is NULL, the Parquet file is not deleted.

table_id

BIGINT

Foreign key, NOT NULL

The ID of the analytical table from the pga_table metadata table associated with the Parquet file.

file_order

BIGINT

NOT NULL

The vertical position of the Parquet file.

file_order values must be unique. However, their sequence can be interrupted, i.e., empty values are possible.

path

VARCHAR

NOT NULL, UNIQUE

The path to the Parquet file, for example, my_file.parquet.

path_is_relative

BOOLEAN

NOT NULL

Specifies whether the path to the Parquet file is relative to the path to the analytical table or absolute.

Possible values:

  • true

  • false

Default value: false.

file_format

VARCHAR

NOT NULL

The file format.

Currently, only the Parquet format is supported.

record_count

BIGINT

NOT NULL

The number of rows in the Parquet file.

file_size_bytes

BIGINT

NOT NULL

The Parquet file size, in bytes.

row_id_start

BIGINT

NOT NULL

The row_id value for the first row corresponding to the Parquet file. Indicates where rows corresponding to the Parquet file start.

checksum_crc32

BIGINT

NOT NULL

The current checksum value of the Parquet file.

It is used for data integrity checks.