ClickHouse/docs/en/system_tables/system.parts.md

system.parts

Contains information about parts of a table in the MergeTree family.

Each row describes one part of the data.

Columns:

• partition (String) – The partition name. YYYYMM format. To learn what a partition is, see the description of the ALTER query.
• name (String) – Name of the data part.
• active (UInt8) – Indicates whether the part is active. If a part is active, it is used in a table; otherwise, it will be deleted. Inactive data parts remain after merging.
• marks (UInt64) – The number of marks. To get the approximate number of rows in a data part, multiply marks by the index granularity (usually 8192).
• marks_size (UInt64) – The size of the file with marks.
• rows (UInt64) – The number of rows.
• bytes (UInt64) – The number of bytes when compressed.
• modification_time (DateTime) – The modification time of the directory with the data part. This usually corresponds to the time of data part creation.|
• remove_time (DateTime) – The time when the data part became inactive.
• refcount (UInt32) – 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) – The minimum value of the date key in the data part.
• max_date (Date) – The maximum value of the date key in the data part.
• min_block_number (UInt64) – The minimum number of data parts that make up the current part after merging.
• max_block_number (UInt64) – The maximum number of data parts that make up the current part after merging.
• level (UInt32) – Depth of the merge tree. If a merge was not performed, level=0.
• primary_key_bytes_in_memory (UInt64) – The amount of memory (in bytes) used by primary key values.
• primary_key_bytes_in_memory_allocated (UInt64) – The amount of memory (in bytes) reserved for primary key values.
• database (String) – Name of the database.
• table (String) – Name of the table.
• engine (String) – Name of the table engine without parameters.