The Delta Lake connector allows ingestion from a Delta Lake data platform hosted in S3 and GCS into Pinot. The ingestion is done as a periodic pull based system that is executed by the Pinot Minion framework. You specify the period that you want the ingestion task to follow and on each trigger Minion will check if there has been a change to the Delta Lake since the last execution and, if there has, it will ingest the new data. StarTree’s Delta Lake connector supports both the older Standalone Delta Lake API and the new Delta Kernel API. With the Delta Kernel API, the StarTree Delta Lake connector also supports the use of Deletion Vectors.

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Prerequisites

  • Delta Lake ingestion can only be enabled for offline Pinot tables
  • This connector supports Delta tables hosted on Amazon S3 and Google Cloud Storage(GCS).
  • This connector supports only sync mode, meaning each file in Delta Lake maps to a single segment in Pinot. Therefore, it is recommended to size the files appropriately to avoid creating an excessive number of segments. Find the official documentation on how to tune the size of files in your Delta table.

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Limitations

  • Support for ADLS is not yet available.
  • Support for Delta column mapping is not yet available. Column Mapping feature should be kept disabled.
  • Delta tasks do not utilize checkpoints. Consequently, no table entry is created at the ZK path PROPERTYSTORE→MINION_TASK_METADATA. This limitation applies to both Delta Standalone mode and Delta Kernel mode. Tasks will fail if not completed within one day, as Delta does not track progress. Subsequent triggers will generate new tasks to resume processing.

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Pinot Table Configuration

The offline table task configs can be manually set with the following connection and ingestion parameters.

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Connection Parameters

All the following properties are required to establish connection with Delta Tables.
Property NameRequiredDescription
delta.ingestion.table.fsYesMust be set to “S3” or “GCS”
delta.ingestion.table.uriYesIt is the source location of the Delta Lake table.
For Amazon S3, the URI should start with: s3a://<bucket-name>/path/to/delta-table.
For GCS, the URI should start with: gs://<bucket-name>/path/to/delta-table.
delta.ingestion.useDeltaKernelNoWhen set to "true" this will make the Delta Lake connector use the Delta Kernel API. When not provided this will default to false. It should be set to true, when delta table is hosted on GCS
tableMaxNumTasksNoThis is used to determine how to partition ingestion jobs across Minion workers
scheduleYesThis sets the schedule for execution and uses the Quartz schedule format for setting the schedule
segmentIngestionTypeYesIt should be set to REFRESH. As the complete segment is replaced every time during ingestion for a particular file. This configuration is part of ingestionConfig.batchIngestionConfig

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Authentication Parameters

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Delta Tables hosted on S3 via Basic Authentication

Use the following JSON configuration when Delta is set up on S3 with Basic Authentication 
"ingestionConfig": {
    "batchIngestionConfig": {
      "segmentIngestionType": "REFRESH"
    }
  }

"task": {
      "taskTypeConfigsMap": {
        "DeltaTableIngestionTask": {
          "delta.ingestion.table.fs": "S3",
          "delta.ingestion.useDeltaKernel": "true",
          "delta.ingestion.table.uri": "s3a://bucket-name/path/to/delta-table",
          "delta.ingestion.table.s3.accessKey": "myAccessKey",
          "delta.ingestion.table.s3.secretKey": "mySecretKey",
          "delta.ingestion.table.s3.region": "us-west-2",
          "schedule": "0 20 * ? * * *",
          "tableMaxNumTasks": "1000"
        }
      }
    }

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Property Descriptions

Property NameRequiredDescription
delta.ingestion.table.s3.regionYesThe AWS region that houses the Delta Lake.
delta.ingestion.table.s3.accessKeyNoIf you are using Access Key based authorization then this is for the AWS access key. You will also need the AWS Secret Key below.
delta.ingestion.table.s3.secretKeyNoThe AWS Secret Key.

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Delta Tables hosted on S3 via IAM based Authentication

"ingestionConfig": {
    "batchIngestionConfig": {
      "segmentIngestionType": "REFRESH"
    }
  }

"task": {
      "taskTypeConfigsMap": {
        "DeltaTableIngestionTask": {
          {
                  "tableMaxNumTasks": "1000",
                  "schedule": "0 20 * ? * * *",
                  "delta.ingestion.useDeltaKernel": "true",
                  "delta.ingestion.table.fs": "S3",
                  "delta.ingestion.table.uri": "s3a://my-bucket/my-data-directory/",
                  "delta.ingestion.table.s3.role.arn": "arn:aws:iam::123456789012:role/PinotS3AccessRole",
                  "delta.ingestion.table.s3.region": "s3_region",
                  "fs.s3a.assumed.role.arn": "arn:aws:iam::123456789012:role/PinotS3AccessRole",
                  "fs.s3a.assumed.role.sts.endpoint": "https://sts.region.amazonaws.com",
                  "fs.s3a.assumed.role.sts.endpoint.region": "s3_region",
                  "fs.s3a.aws.credentials.provider": "ai.startree.connectors.auth.AssumedRoleCredentialsProvider",
                  "fs.s3a.assumed.role.credentials.provider": "com.amazonaws.auth.InstanceProfileCredentialsProvider"
          }
        }
      }
    }

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Property Descriptions

If you are using IAM to managed access to your S3 bucket then, use the following parameters:
Property NameRequiredDescription
delta.ingestion.table.s3.regionYesThe AWS region that houses the Delta Lake.
delta.ingestion.table.s3.role.arnYes"arn:aws:iam::REPLACE_WITH_AWS_ACCOUNT_ID_WHERE_DATA_RESIDES:role/DataManagerDeltaLakeS3IAMRole"
fs.s3a.aws.credentials.providerYesMust be "org.apache.hadoop.fs.s3a.auth.AssumedRoleCredentialProvider" on StarTree Pinot versions 1.2.0* and "ai.startree.connectors.auth.AssumedRoleCredentialsProvider" on StarTree Pinot versions 1.3.0*.
fs.s3a.assumed.role.sts.endpointYesThe STS endpoint for your account (e.g., https://sts.us-west-2.amazonaws.com)
fs.s3a.assumed.role.sts.endpoint.regionYesThe Region for your account (e.g, us-west-2)
fs.s3a.assumed.role.arnYesThe ARN For the Role that will be assumed to get access ("arn:aws:iam::REPLACE_WITH_AWS_ACCOUNT_ID_WHERE_DATA_RESIDES:role/DataManagerDeltaLakeS3IAMRole")
fs.s3a.assumed.role.credentials.providerYesMust be com.amazonaws.auth.InstanceProfileCredentialsProvider. Used to gain a set of temporary security credentials to access an ARN that is in an account outside of the StarTree cluster.

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Delta Tables hosted on GCS

Use the following JSON configuration when Delta is set up on GCS 
"ingestionConfig": {
    "batchIngestionConfig": {
      "segmentIngestionType": "REFRESH"
    }
  }

"task": {
      "taskTypeConfigsMap": {
        "DeltaTableIngestionTask": {
          "delta.ingestion.table.fs": "GCS",
          "delta.ingestion.useDeltaKernel": "true",
          "delta.ingestion.table.uri": "gs://bucket-name/path/to/delta-table",
          "delta.ingestion.table.gcs.projectId": "project_id_123",
          "delta.ingestion.table.gcs.keyContentBase64": "hraUc5dzBCQVFFRkFBU0NCS2d3Z2dTa=",
          "schedule": "0 20 * ? * * *",
          "tableMaxNumTasks": "1000"
        }
      }
    }

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Property Descriptions

Property NameRequiredDescription
delta.ingestion.table.gcs.projectIdYesIt is the GCP project ID associated with the bucket that stores Delta Lake data.
delta.ingestion.table.gcs.keyContentBase64NoIt is used to specify the Google Cloud Service Account key in Base64-encoded format for authentication when accessing Delta Lake data stored in GCS. delta.ingestion.table.gcs.keyFile can be alternatively used instead of this parameter. See Google documentation on how to create a service account key.
delta.ingestion.table.gcs.keyFileNoIt specifies the path to the Google Cloud Service Account key file used for authentication when accessing Delta Lake data stored in a GCS bucket. It should be available locally in all minions. delta.ingestion.table.gcs.keyContentBase64 can be alternatively used instead of this parameter.

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Frequently Asked Questions

StarTree uses Delta Kernel Library to get the updated list of files and uses the Minion framework to manage data segments. Every time a row is added, updated, or deleted in Delta, the underlying files change, which updates the table version. Pinot detects these changes and updates its corresponding table segments accordingly — ensuring the latest state is always reflected.If there are 1M rows in a table and only one row is updated. This will result into update in one segment only since file and segment has 1:1 mapping. In other words,
  • If all 1M rows are stored in a single file and hence one single segment, the entire segment will be replaced even if just one row changes.
  • If the 1M rows are split across 10 files, only the relevant segment (1 out of 10) mapped to the particular file containing the updated rowz will be replaced.
Pinot processes Delta’s transaction logs and uses the Minion framework to manage data segments. Every time a row is added, updated, or deleted in Delta, the underlying files change, which updates the table version. Pinot detects these changes and updates its corresponding table segments accordingly — ensuring the latest state is always reflected.The key impact is at the segment level in Pinot:
  • If all 1M rows are stored in a single segment, the entire segment will be replaced even if just one row changes.
  • If the 1M rows are split across 10 segments, only the relevant segment (1 out of 10) containing the updated row will be replaced.
This ensures Pinot always reflects the latest state while maintaining efficient resource usage, depending on how the segments are structured.
Yes, you can. Pinot supports high-frequency scheduling, including a 1-minute refresh. This will create one ingestion task per minute. However, if you’re targeting sub-minute or near real-time updates, a streaming ingestion approach may be more efficient.
Not at the moment. Unity Catalog support is currently not available in the Delta Kernel libraries, so Pinot doesn’t support it either. As a workaround, you can filter out restricted columns while creating the Pinot table.
No. Pinot uses an internal watermark system via Zookeeper to avoid scanning all files every time. It only checks for new files added after the watermark. DeltaIngestionTask (Delta ingestion) relies on Delta’s transaction logs. Starting from version 1.3.0, it no longer uses a watermark — it simply applies the differences between versions.
No, Column Mapping is not supported. Column Mapping feature should be kept disabled to ensure smooth ingestion.