mirror of https://github.com/apache/druid.git
61 lines
2.6 KiB
Markdown
61 lines
2.6 KiB
Markdown
---
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id: delta-lake
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title: "Delta Lake extension"
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---
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<!--
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~ Licensed to the Apache Software Foundation (ASF) under one
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~ or more contributor license agreements. See the NOTICE file
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~ regarding copyright ownership. The ASF licenses this file
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~ to you under the Apache License, Version 2.0 (the
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~ "License"); you may not use this file except in compliance
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~ with the License. You may obtain a copy of the License at
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~ http://www.apache.org/licenses/LICENSE-2.0
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## Delta Lake extension
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Delta Lake is an open source storage framework that enables building a
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Lakehouse architecture with various compute engines. [DeltaLakeInputSource](../../ingestion/input-sources.md#delta-lake-input-source) lets
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you ingest data stored in a Delta Lake table into Apache Druid. To use the Delta Lake extension, add the `druid-deltalake-extensions` to the list of loaded extensions.
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See [Loading extensions](../../configuration/extensions.md#loading-extensions) for more information.
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The Delta input source reads the configured Delta Lake table and extracts all the underlying delta files in the table's latest snapshot.
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These Delta Lake files are versioned Parquet files.
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## Version support
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The Delta Lake extension uses the Delta Kernel introduced in Delta Lake 3.0.0, which is compatible with Apache Spark 3.5.x.
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Older versions are unsupported, so consider upgrading to Delta Lake 3.0.x or higher to use this extension.
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## Downloading Delta Lake extension
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To download `druid-deltalake-extensions`, run the following command after replacing `<VERSION>` with the desired
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Druid version:
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```shell
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java \
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-cp "lib/*" \
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-Ddruid.extensions.directory="extensions" \
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-Ddruid.extensions.hadoopDependenciesDir="hadoop-dependencies" \
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org.apache.druid.cli.Main tools pull-deps \
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--no-default-hadoop \
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-c "org.apache.druid.extensions.contrib:druid-deltalake-extensions:<VERSION>"
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```
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See [Loading community extensions](../../configuration/extensions.md#loading-community-extensions) for more information.
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## Known limitations
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- This extension relies on the Delta Kernel API and can only read from the latest Delta table snapshot.
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- Column filtering isn't supported. The extension reads all columns in the configured table. |