# ExportedDataPropertyDef

Location: [gRPC API](https://developer.m-files.com/APIs/gRPC-API/index.md) > [Reference](https://developer.m-files.com/APIs/gRPC-API/Reference/index.md) > [Messages](https://developer.m-files.com/APIs/gRPC-API/Reference/Messages/index.md)

HTML version: https://developer.m-files.com/APIs/gRPC-API/Reference/Messages/MFiles.ExportedDataPropertyDef/

Property definition node for extracted data schema.

- **Full name:** `MFiles.ExportedDataPropertyDef`
- **Proto file:** [`mfiles/structs.proto`](https://developer.m-files.com/APIs/gRPC-API/downloads/proto/mfiles/structs.proto)

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## Fields

| Field | Type | Number | Description |
|---|---|---|---|
| <a id="f-property_def"></a>`property_def` | `int32` | 1 | Property definition ID. |
| <a id="f-export_history_as_changes"></a>`export_history_as_changes` | `bool` | 2 | True to export historical data as change events. |
| <a id="f-export_history_as_timeline"></a>`export_history_as_timeline` | `bool` | 3 | True to export historical data as sampled timeline. |
| <a id="f-sampling_interval"></a>`sampling_interval` | [`ExportedDataHistoryInterval`](https://developer.m-files.com/APIs/gRPC-API/Reference/Enums/MFiles.ExportedDataHistoryInterval/index.md) | 4 | Timeline sampling interval Values: `EXPORTED_DATA_HISTORY_INTERVAL_DAY` (0), `EXPORTED_DATA_HISTORY_INTERVAL_WEEK` (1), `EXPORTED_DATA_HISTORY_INTERVAL_MONTH` (2), `EXPORTED_DATA_HISTORY_INTERVAL_YEAR` (3). |
| <a id="f-history_mode"></a>`history_mode` | [`ExportedDataHistoryStartDateMode`](https://developer.m-files.com/APIs/gRPC-API/Reference/Enums/MFiles.ExportedDataHistoryStartDateMode/index.md) | 5 | The mode how the history start date is expressed. Values: `EXPORTED_DATA_HISTORY_START_DATE_MODE_FULL_HISTORY` (0), `EXPORTED_DATA_HISTORY_START_DATE_MODE_FIXED_PERIOD` (1), `EXPORTED_DATA_HISTORY_START_DATE_MODE_STARTING_FROM` (2). |
| <a id="f-fixed_period_length"></a>`fixed_period_length` | `uint32` | 6 | Length of the period. Valid only if the start date is a fixed period. |
| <a id="f-fixed_period_unit"></a>`fixed_period_unit` | [`ExportedDataHistoryInterval`](https://developer.m-files.com/APIs/gRPC-API/Reference/Enums/MFiles.ExportedDataHistoryInterval/index.md) | 7 | The period unit for fixed period. Values: `EXPORTED_DATA_HISTORY_INTERVAL_DAY` (0), `EXPORTED_DATA_HISTORY_INTERVAL_WEEK` (1), `EXPORTED_DATA_HISTORY_INTERVAL_MONTH` (2), `EXPORTED_DATA_HISTORY_INTERVAL_YEAR` (3). |
| <a id="f-starting_from_date"></a>`starting_from_date` | [`google.protobuf.Timestamp`](https://protobuf.dev/reference/protobuf/google.protobuf/#timestamp) | 8 | Exact start date. Valid only if the eedtstmStartDate is eedhsdmExactDate. |
| <a id="f-child_nodes"></a>`child_nodes` | repeated [`ExportedDataPropertyDef`](https://developer.m-files.com/APIs/gRPC-API/Reference/Messages/MFiles.ExportedDataPropertyDef/index.md) | 9 | Hierarchical child property definition nodes. |

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## Used in fields

- [`ExportedDataObjectType.property_defs`](https://developer.m-files.com/APIs/gRPC-API/Reference/Messages/MFiles.ExportedDataObjectType/index.md#f-property_defs): Child property definition nodes.
- [`ExportedDataPropertyDef.child_nodes`](https://developer.m-files.com/APIs/gRPC-API/Reference/Messages/MFiles.ExportedDataPropertyDef/index.md#f-child_nodes): Hierarchical child property definition nodes.