aokolnychyi commented on code in PR #7105: URL: https://github.com/apache/iceberg/pull/7105#discussion_r1351007189
########## format/spec.md: ########## @@ -702,6 +703,58 @@ Blob metadata is a struct with the following fields: | _optional_ | _optional_ | **`properties`** | `map<string, string>` | Additional properties associated with the statistic. Subset of Blob properties in the Puffin file. | +#### Partition statistics + +Partition statistics files are based on [Partition Statistics file spec](#partition-statistics-file). +Partition statistics are not required for reading or planning and readers may ignore them. +Each table snapshot may be associated with at most one partition statistic file. +A writer can optionally write the partition statistics file during each write operation, and +it must be registered in the table metadata file to be considered as a valid statistics file for the reader. + +`partition-statistics` field of table metadata is an optional list of struct with the following fields: + +| v1 | v2 | Field name | Type | Description | +|----|----|------------|------|-------------| +| _required_ | _required_ | **`snapshot-id`** | `long` | ID of the Iceberg table's snapshot the partition statistics file is associated with. | +| _required_ | _required_ | **`statistics-file-path`** | `string` | Path of the partition statistics file. See [Partition Statistics file](#partition-statistics-file). | +| _required_ | _required_ | **`file-size-in-bytes`** | `long` | Size of the partition statistics file. | + +#### Partition Statistics file Review Comment: Question: Shall `file` be `File` since it is a header? ########## format/spec.md: ########## @@ -702,6 +703,58 @@ Blob metadata is a struct with the following fields: | _optional_ | _optional_ | **`properties`** | `map<string, string>` | Additional properties associated with the statistic. Subset of Blob properties in the Puffin file. | +#### Partition statistics + +Partition statistics files are based on [Partition Statistics file spec](#partition-statistics-file). Review Comment: Question: Is there a particular reason to use capital letters for `Partition Statistics`? It seems inconsistent with other places. ########## format/spec.md: ########## @@ -702,6 +703,58 @@ Blob metadata is a struct with the following fields: | _optional_ | _optional_ | **`properties`** | `map<string, string>` | Additional properties associated with the statistic. Subset of Blob properties in the Puffin file. | +#### Partition statistics + +Partition statistics files are based on [Partition Statistics file spec](#partition-statistics-file). +Partition statistics are not required for reading or planning and readers may ignore them. +Each table snapshot may be associated with at most one partition statistic file. +A writer can optionally write the partition statistics file during each write operation, and +it must be registered in the table metadata file to be considered as a valid statistics file for the reader. + +`partition-statistics` field of table metadata is an optional list of struct with the following fields: + +| v1 | v2 | Field name | Type | Description | +|----|----|------------|------|-------------| +| _required_ | _required_ | **`snapshot-id`** | `long` | ID of the Iceberg table's snapshot the partition statistics file is associated with. | +| _required_ | _required_ | **`statistics-file-path`** | `string` | Path of the partition statistics file. See [Partition Statistics file](#partition-statistics-file). | Review Comment: I see your point but isn't it also a path to a single file in case of table stats? I would align the naming to be consistent if it indicates a path to a single file in both cases. ########## format/spec.md: ########## @@ -702,6 +703,58 @@ Blob metadata is a struct with the following fields: | _optional_ | _optional_ | **`properties`** | `map<string, string>` | Additional properties associated with the statistic. Subset of Blob properties in the Puffin file. | +#### Partition statistics + +Partition statistics files are based on [Partition Statistics file spec](#partition-statistics-file). +Partition statistics are not required for reading or planning and readers may ignore them. +Each table snapshot may be associated with at most one partition statistic file. +A writer can optionally write the partition statistics file during each write operation, and Review Comment: Shall we add a note that it can be also computed on demand rather that in each write? ########## format/spec.md: ########## @@ -702,6 +703,58 @@ Blob metadata is a struct with the following fields: | _optional_ | _optional_ | **`properties`** | `map<string, string>` | Additional properties associated with the statistic. Subset of Blob properties in the Puffin file. | +#### Partition statistics + +Partition statistics files are based on [Partition Statistics file spec](#partition-statistics-file). +Partition statistics are not required for reading or planning and readers may ignore them. +Each table snapshot may be associated with at most one partition statistic file. +A writer can optionally write the partition statistics file during each write operation, and +it must be registered in the table metadata file to be considered as a valid statistics file for the reader. + +`partition-statistics` field of table metadata is an optional list of struct with the following fields: + +| v1 | v2 | Field name | Type | Description | +|----|----|------------|------|-------------| +| _required_ | _required_ | **`snapshot-id`** | `long` | ID of the Iceberg table's snapshot the partition statistics file is associated with. | +| _required_ | _required_ | **`statistics-file-path`** | `string` | Path of the partition statistics file. See [Partition Statistics file](#partition-statistics-file). | +| _required_ | _required_ | **`file-size-in-bytes`** | `long` | Size of the partition statistics file. | + +#### Partition Statistics file + +Statistics information for each unique partition tuple is stored as a row in the default data file format of the table (for example, Parquet or ORC). +These rows must be sorted (in ascending manner with NULL FIRST) by `partition` field to optimize filtering rows while scanning. + +The schema of the partition statistics file is as follows: + +| v1 | v2 | Field id, name | Type | Description | +|----|----|----------------|------|-------------| +| _required_ | _required_ | **`1 partition`** | `struct<..>` | Partition data tuple, schema based on the unified partition type considering all specs in a table | +| _required_ | _required_ | **`2 spec_id`** | `int` | Partition spec id | +| _required_ | _required_ | **`3 data_record_count`** | `long` | Count of records in data files | +| _required_ | _required_ | **`4 data_file_count`** | `int` | Count of data files | +| _required_ | _required_ | **`5 total_data_file_size_in_bytes`** | `long` | Total size of data files in bytes | +| _optional_ | _optional_ | **`6 position_delete_record_count`** | `long` | Count of records in position delete files | +| _optional_ | _optional_ | **`7 position_delete_file_count`** | `int` | Count of position delete files | +| _optional_ | _optional_ | **`8 equality_delete_record_count`** | `long` | Count of records in equality delete files | +| _optional_ | _optional_ | **`9 equality_delete_file_count`** | `int` | Count of equality delete files | +| _optional_ | _optional_ | **`10 total_record_count`** | `long` | Accurate count of records in a partition after applying the delete files if any | Review Comment: Am I right this would only be possible to compute by reading data and applying deletes? If so, are we planning to make this optional and not populate by default? ########## format/spec.md: ########## @@ -702,6 +703,58 @@ Blob metadata is a struct with the following fields: | _optional_ | _optional_ | **`properties`** | `map<string, string>` | Additional properties associated with the statistic. Subset of Blob properties in the Puffin file. | +#### Partition statistics + +Partition statistics files are based on [Partition Statistics file spec](#partition-statistics-file). +Partition statistics are not required for reading or planning and readers may ignore them. +Each table snapshot may be associated with at most one partition statistic file. +A writer can optionally write the partition statistics file during each write operation, and +it must be registered in the table metadata file to be considered as a valid statistics file for the reader. + +`partition-statistics` field of table metadata is an optional list of struct with the following fields: + +| v1 | v2 | Field name | Type | Description | Review Comment: This seems reasonable, we can add it later. ########## format/spec.md: ########## @@ -702,6 +703,58 @@ Blob metadata is a struct with the following fields: | _optional_ | _optional_ | **`properties`** | `map<string, string>` | Additional properties associated with the statistic. Subset of Blob properties in the Puffin file. | +#### Partition statistics + +Partition statistics files are based on [Partition Statistics file spec](#partition-statistics-file). +Partition statistics are not required for reading or planning and readers may ignore them. +Each table snapshot may be associated with at most one partition statistic file. +A writer can optionally write the partition statistics file during each write operation, and +it must be registered in the table metadata file to be considered as a valid statistics file for the reader. + +`partition-statistics` field of table metadata is an optional list of struct with the following fields: + +| v1 | v2 | Field name | Type | Description | +|----|----|------------|------|-------------| +| _required_ | _required_ | **`snapshot-id`** | `long` | ID of the Iceberg table's snapshot the partition statistics file is associated with. | +| _required_ | _required_ | **`statistics-file-path`** | `string` | Path of the partition statistics file. See [Partition Statistics file](#partition-statistics-file). | +| _required_ | _required_ | **`file-size-in-bytes`** | `long` | Size of the partition statistics file. | + +#### Partition Statistics file + +Statistics information for each unique partition tuple is stored as a row in the default data file format of the table (for example, Parquet or ORC). Review Comment: I am not sure it is a good idea for the spec to make this assumption. I can see this being configurable even for tables that store Avro data to use Parquet or ORC for partition stats. Why can't we just default this in the implementation? -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: issues-unsubscr...@iceberg.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: issues-unsubscr...@iceberg.apache.org For additional commands, e-mail: issues-h...@iceberg.apache.org
