title_wip

- `uuid` ([UUID](/docs/sql-reference/data-types/uuid)) - The UUID of data part.
- `part_type` ([String](/docs/sql-reference/data-types/string)) — The data part storing format.

  Possible Values:

  - `Wide` — Each column is stored in a separate file in a filesystem.
  - `Compact` — All columns are stored in one file in a filesystem.

    Data storing format is controlled by the `min_bytes_for_wide_part` and `min_rows_for_wide_part` settings of the [MergeTree](/docs/engines/table-engines/mergetree-family/mergetree) table.
- `active` ([UInt8](/docs/sql-reference/data-types/int-uint)) – Flag that indicates whether the data part is active. If a data part is active, it's used in a table. Otherwise, it's deleted. Inactive data parts remain after merging.
- `marks` ([UInt64](/docs/sql-reference/data-types/int-uint)) – The number of marks. To get the approximate number of rows in a data part, multiply `marks` by the index granularity (usually 8192) (this hint does not work for adaptive granularity).
- `rows` ([UInt64](/docs/sql-reference/data-types/int-uint)) – The number of rows.
- `bytes_on_disk` ([UInt64](/docs/sql-reference/data-types/int-uint)) – Total size of all the data part files in bytes.
- `data_compressed_bytes` ([UInt64](/docs/sql-reference/data-types/int-uint)) – Total size of compressed data in the data part. All the auxiliary files (for example, files with marks) are not included.
- `data_uncompressed_bytes` ([UInt64](/docs/sql-reference/data-types/int-uint)) – Total size of uncompressed data in the data part. All the auxiliary files (for example, files with marks) are not included.
- `primary_key_size` ([UInt64](/docs/sql-reference/data-types/int-uint)) – The amount of memory (in bytes) used by primary key values in the primary.idx/cidx file on disk.
- `marks_bytes` ([UInt64](/docs/sql-reference/data-types/int-uint)) – The size of the file with marks.
- `files` ([UInt64](/docs/sql-reference/data-types/int-uint)) – The number of files in the data part.
- `secondary_indices_compressed_bytes` ([UInt64](/docs/sql-reference/data-types/int-uint)) – Total size of compressed data for secondary indices in the data part. All the auxiliary files (for example, files with marks) are not included.
- `secondary_indices_uncompressed_bytes` ([UInt64](/docs/sql-reference/data-types/int-uint)) – Total size of uncompressed data for secondary indices in the data part. All the auxiliary files (for example, files with marks) are not included.
- `secondary_indices_marks_bytes` ([UInt64](/docs/sql-reference/data-types/int-uint)) – The size of the file with marks for secondary indices.
- `modification_time` ([DateTime](/docs/sql-reference/data-types/datetime)) – The time the directory with the data part was modified. This usually corresponds to the time of data part creation.
- `remove_time` ([DateTime](/docs/sql-reference/data-types/datetime)) – The time when the data part became inactive.
- `refcount` ([UInt32](/docs/sql-reference/data-types/int-uint)) – The number of places where the data part is used. A value greater than 2 indicates that the data part is used in queries or merges.
- `min_date` ([Date](/docs/sql-reference/data-types/date)) – The minimum value of the date key in the data part.
- `max_date` ([Date](/docs/sql-reference/data-types/date)) – The maximum value of the date key in the data part.
- `min_time` ([DateTime](/docs/sql-reference/data-types/datetime)) – The minimum value of the date and time key in the data part.
- `max_time`([DateTime](/docs/sql-reference/data-types/datetime)) – The maximum value of the date and time key in the data part.
- `partition_id` ([String](/docs/sql-reference/data-types/string)) – ID of the partition.
- `min_block_number` ([UInt64](/docs/sql-reference/data-types/int-uint)) – The minimum data block number that makes up the current part after merging.
- `max_block_number` ([UInt64](/docs/sql-reference/data-types/int-uint)) – The maximum data block number that makes up the current part after merging.
- `level` ([UInt32](/docs/sql-reference/data-types/int-uint)) – Depth of the merge tree. Zero means that the current part was created by insert rather than by merging other parts.
- `data_version` ([UInt64](/docs/sql-reference/data-types/int-uint)) – Number that is used to determine which mutations should be applied to the data part (mutations with a version higher than `data_version`).
- `primary_key_bytes_in_memory` ([UInt64](/docs/sql-reference/data-types/int-uint)) – The amount of memory (in bytes) used by primary key values (will be `0` in case of `primary_key_lazy_load=1` and `use_primary_key_cache=1`).
- `primary_key_bytes_in_memory_allocated` ([UInt64](/docs/sql-reference/data-types/int-uint)) – The amount of memory (in bytes) reserved for primary key values (will be `0` in case of `primary_key_lazy_load=1` and `use_primary_key_cache=1`).
- `is_frozen` ([UInt8](/docs/sql-reference/data-types/int-uint)) – Flag that shows that a partition data backup exists. 1, the backup exists. 0, the backup does not exist. For more details, see [FREEZE PARTITION](/docs/sql-reference/statements/alter/partition#freeze-partition)
- `database` ([String](/docs/sql-reference/data-types/string)) – Name of the database.
- `table` ([String](/docs/sql-reference/data-types/string)) – Name of the table.
- `engine` ([String](/docs/sql-reference/data-types/string)) – Name of the table engine without parameters.
- `path` ([String](/docs/sql-reference/data-types/string)) – Absolute path to the folder with data part files.
- `disk_name` ([String](/docs/sql-reference/data-types/string)) – Name of a disk that stores the data part.
- `hash_of_all_files` ([String](/docs/sql-reference/data-types/string)) – [sipHash128](/docs/sql-reference/functions/hash-functions#sipHash128) of compressed files.
- `hash_of_uncompressed_files` ([String](/docs/sql-reference/data-types/string)) – [sipHash128](/docs/sql-reference/functions/hash-functions#sipHash128) of uncompressed files (files with marks, index file etc.).
- `uncompressed_hash_of_compressed_files` ([String](/docs/sql-reference/data-types/string)) – [sipHash128](/docs/sql-reference/functions/hash-functions#sipHash128) of data in the compressed files as if they were uncompressed.
- `delete_ttl_info_min` ([DateTime](/docs/sql-reference/data-types/datetime)) — The minimum value of the date and time key for [TTL DELETE rule](/docs/engines/table-engines/mergetree-family/mergetree#table_engine-mergetree-ttl).
- `delete_ttl_info_max` ([DateTime](/docs/sql-reference/data-types/datetime)) — The maximum value of the date and time key for [TTL DELETE rule](/docs/engines/table-engines/mergetree-family/mergetree#table_engine-mergetree-ttl).
- `move_ttl_info.expression` ([Array](/docs/sql-reference/data-types/array)([String](/docs/sql-reference/data-types/string))) — Array of expressions. Each expression defines a [TTL MOVE rule](/docs/engines/table-engines/mergetree-family/mergetree#table_engine-mergetree-ttl).

Note

The `move_ttl_info.expression` array is kept mostly for backward compatibility, now the simplest way to check `TTL MOVE` rule is to use the `move_ttl_info.min` and `move_ttl_info.max` fields.

- `move_ttl_info.min` ([Array](/docs/sql-reference/data-types/array)([DateTime](/docs/sql-reference/data-types/datetime))) — Array of date and time values. Each element describes the minimum key value for a [TTL MOVE rule](/docs/engines/table-engines/mergetree-family/mergetree#table_engine-mergetree-ttl).
- `move_ttl_info.max` ([Array](/docs/sql-reference/data-types/array)([DateTime](/docs/sql-reference/data-types/datetime))) — Array of date and time values. Each element describes the maximum key value for a [TTL MOVE rule](/docs/engines/table-engines/mergetree-family/mergetree#table_engine-mergetree-ttl).
- `bytes` ([UInt64](/docs/sql-reference/data-types/int-uint)) – Alias for `bytes_on_disk`.
- `marks_size` ([UInt64](/docs/sql-reference/data-types/int-uint)) – Alias for `marks_bytes`.

**Example**

```
SELECT * FROM system.parts LIMIT 1 FORMAT Vertical;
```