> ## Documentation Index > Fetch the complete documentation index at: https://help.lobyco.com/llms.txt > Use this file to discover all available pages before exploring further. # Read Change Data Feed from a Table > This is the API for clients to read change data feed from a table. The API supports a start parameter and and an end parameter. The start/end parameter can either be a version or a timestamp. The start parameter must be provided. If the end parameter is not provided, the API will use the latest table version for it. The parameter range is inclusive in the query. You can specify a version as a Long or a timestamp as a string in the Timestamp Format. The change data feed represents row-level changes between versions of a Delta table. It records change data for UPDATE, DELETE, and MERGE operations. If you leverage the connectors provided by this library to read change data feed, it results in three metadata columns that identify the type of change event, in addition to the data columns: _change_type (type: String): There are four values: insert, update_preimage, update_postimage, delete. preimage is the value before the udpate, postimage is the value after the update. _commit_version (type: Long): The table version containing the change. _commit_timestamp (type: Long): The unix timestamp associated when the commit of the change was created, in milliseconds. ## OpenAPI ````yaml openapi/delta-sharing-v0-2.yaml GET /shares/{share}/schemas/{schema}/tables/{table}/changes openapi: 3.0.2 info: description: | The Delta Sharing protocol is still very early in its development. version: '0.2' title: Delta Sharing Protocol license: name: AGPL v3.0 url: https://www.gnu.org/licenses/agpl-3.0.en.html servers: - url: http://localhost:8000/api/v1 description: Local dev server (APIv1) - url: https://sharing.delta.io/delta-sharing/ description: Demo Delta Sharing server security: [] tags: - name: shares description: Share discovery APIs - name: schemas description: Schema discovery APIs - name: tables description: Table query and inspection APIs - name: official description: APIs which are part of published official document - name: proposed description: APIs which are part proposed and may or may not be part of official paths: /shares/{share}/schemas/{schema}/tables/{table}/changes: get: tags: - tables - official summary: Read Change Data Feed from a Table description: > This is the API for clients to read change data feed from a table. The API supports a start parameter and and an end parameter. The start/end parameter can either be a version or a timestamp. The start parameter must be provided. If the end parameter is not provided, the API will use the latest table version for it. The parameter range is inclusive in the query. You can specify a version as a Long or a timestamp as a string in the Timestamp Format. The change data feed represents row-level changes between versions of a Delta table. It records change data for UPDATE, DELETE, and MERGE operations. If you leverage the connectors provided by this library to read change data feed, it results in three metadata columns that identify the type of change event, in addition to the data columns: _change_type (type: String): There are four values: insert, update_preimage, update_postimage, delete. preimage is the value before the udpate, postimage is the value after the update. _commit_version (type: Long): The table version containing the change. _commit_timestamp (type: Long): The unix timestamp associated when the commit of the change was created, in milliseconds. operationId: GetTableChanges parameters: - in: path name: share required: true description: Named share for finding the named schema schema: type: string - in: path name: schema required: true description: Named schema for finding the named table schema: type: string - in: path name: table required: true description: Named table schema: type: string - in: query name: startingTimestamp required: false description: >- The starting timestamp of the query, a string in the Timestamp Format, which will be converted to a version created greater or equal to this timestamp. schema: type: string - in: query name: startingVersion required: false description: The starting version of the query, inclusive. schema: type: integer - in: query name: endingVersion required: false description: The ending version of the query, inclusive. schema: type: integer - in: query name: endingTimestamp required: false description: >- The starting timestamp of the query, a string in the Timestamp Format, which will be converted to a version created greater or equal to this timestamp. schema: type: string - in: query name: includeHistoricalMetadata required: false description: >- If set to true, return the historical metadata if seen in the delta log. This is for the streaming client to check if the table schema is still read compatible. schema: type: boolean responses: '200': description: This is the API for clients to read change data feed from a table. content: application/x-ndjson: schema: $ref: '#/components/schemas/ChangeDataFeedResponse' '400': $ref: '#/components/responses/400' '401': $ref: '#/components/responses/401' '403': $ref: '#/components/responses/403' '404': $ref: '#/components/responses/404' '500': $ref: '#/components/responses/500' components: schemas: ChangeDataFeedResponse: type: string example: > {"protocol": {"minReaderVersion": 1}} {"metaData": {"id": "f8d5c169-3d01-4ca3-ad9e-7dc3355aedb2","format": {"provider": "parquet"},"schemaString": "{\"type\":\"struct\",\"fields\":[{\"name\":\"eventTime\",\"type\":\"timestamp\",\"nullable\":true,\"metadata\":{}},{\"name\":\"date\",\"type\":\"date\",\"nullable\":true,\"metadata\":{}}]}","partitionColumns": ["date"],"configuration": {"enableChangeDataFeed": "true"}}}{"add": {"url": "https://.s3.us-west-2.amazonaws.com/delta-exchange-test/table_cdf/date%3D2021-04-28/part-00000-8b0086f2-7b27-4935-ac5a-8ed6215a6640.c000.snappy.parquet?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Date=20210501T010516Z&X-Amz-SignedHeaders=host&X-Amz-Expires=900&X-Amz-Credential=AKIAISZRDL4Q4Q7AIONA%2F20210501%2Fus-west-2%2Fs3%2Faws4_request&X-Amz-Signature=97b6762cfd8e4d7e94b9d707eff3faf266974f6e7030095c1d4a66350cfd892e","id": "8b0086f2-7b27-4935-ac5a-8ed6215a6640","partitionValues": {"date": "2021-04-28"},"size":573,"stats": "{\"numRecords\":1,\"minValues\":{\"eventTime\":\"2021-04-28T23:33:57.955Z\"},\"maxValues\":{\"eventTime\":\"2021-04-28T23:33:57.955Z\"},\"nullCount\":{\"eventTime\":0}}","timestamp": 1652140000000,"version": 0}} {"cdf": {"url": "https://.s3.us-west-2.amazonaws.com/delta-exchange-test/table_cdf/_change_data/date%3D2021-04-28/part-00000-591723a8-6a27-4240-a90e-57426f4736d2.c000.snappy.parquet?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Date=20210501T010516Z&X-Amz-SignedHeaders=host&X-Amz-Expires=899&X-Amz-Credential=AKIAISZRDL4Q4Q7AIONA%2F20210501%2Fus-west-2%2Fs3%2Faws4_request&X-Amz-Signature=0f7acecba5df7652457164533a58004936586186c56425d9d53c52db574f6b62","id": "591723a8-6a27-4240-a90e-57426f4736d2","partitionValues": {"date": "2021-04-28"},"size": 689,"timestamp": 1652141000000,"version": 1}} {"remove": {"url": "https://.s3.us-west-2.amazonaws.com/delta-exchange-test/table_cdf/date%3D2021-04-28/part-00000-8b0086f2-7b27-4935-ac5a-8ed6215a6640.c000.snappy.parquet?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Date=20210501T010516Z&X-Amz-SignedHeaders=host&X-Amz-Expires=900&X-Amz-Credential=AKIAISZRDL4Q4Q7AIONA%2F20210501%2Fus-west-2%2Fs3%2Faws4_request&X-Amz-Signature=97b6762cfd8e4d7e94b9d707eff3faf266974f6e7030095c1d4a66350cfd892e","id": "8b0086f2-7b27-4935-ac5a-8ed6215a6640","partitionValues": {"date": "2021-04-28"},"size": 573,"timestamp": 1652142000000,"version": 2}} CommonErrorResponse: type: object properties: errorCode: type: string message: type: string responses: '400': description: The request is malformed content: application/json: schema: $ref: '#/components/schemas/CommonErrorResponse' '401': description: The request is unauthenticated. The bearer token is missing or incorrect content: application/json: schema: $ref: '#/components/schemas/CommonErrorResponse' '403': description: The request is forbidden from being fulfilled content: application/json: schema: $ref: '#/components/schemas/CommonErrorResponse' '404': description: The specified resource was not found content: application/json: schema: $ref: '#/components/schemas/CommonErrorResponse' '500': description: The request is not handled correctly due to a server error content: application/json: schema: $ref: '#/components/schemas/CommonErrorResponse' ````