[Java] Implement converter between Arrow record batches and Avro records
- Dominant language
- Java
- Stars
- 94
- Forks
- 152
- Avg merge
- 3d 16h
- Merged PRs (30d)
- 11
Description
It would be useful for applications which need convert Avro data to Arrow data.
This is an adapter which convert data with existing API (like JDBC adapter) rather than a native reader (like orc).
We implement this function through Avro java project, receiving param like Decoder/Schema/DatumReader of Avro and return VectorSchemaRoot. For each data type we have a consumer class as below to get Avro data and write it into vector to avoid boxing/unboxing (e.g. GenericRecord#get returns Object)
```java
public class AvroIntConsumer implements Consumer {
private final IntWriter writer;
public AvroIntConsumer(IntVector vector)
{ this.writer = new IntWriterImpl(vector); }
@Override
public void consume(Decoder decoder) throws IOException
{ writer.writeInt(decoder.readInt()); writer.setPosition(writer.getPosition() + 1); }
```
We intended to support primitive and complex types (null value represented via unions type with null type), size limit and field selection could be optional for users.
**Reporter**: [Ji Liu](https://issues.apache.org/jira/browse/ARROW-5845) / @tianchen92
#### Subtasks:
- [X] [[Java] Create Avro adapter module and add dependencies](https://github.com/apache/arrow/issues/22265)
- [X] [[Java] Initial implement to convert Avro record with primitive types](https://github.com/apache/arrow/issues/22278)
- [X] [[Java] Avro adapter implement simple Record type ](https://github.com/apache/arrow/issues/22396)
- [X] [[Java] Avro adapter support convert nullable value](https://github.com/apache/arrow/issues/22439)
- [X] [[Java] Avro adapter implement unions type](https://github.com/apache/arrow/issues/22496)
- [X] [[Java] Avro adapter avoid potential resource leak.](https://github.com/apache/arrow/issues/22590)
- [X] [[Java] Add API to avro adapter to limit number of rows returned at a time.](https://github.com/apache/arrow/issues/22608)
- [X] [[Java] Avro adapter implement Array/Map/Fixed type](https://github.com/apache/arrow/issues/22649)
- [X] [[Java] Avro adapter implement Enum type and nested Record type](https://github.com/apache/arrow/issues/16862)
- [X] [[Java] Add benchmark and large fake data UT for avro adapter](https://github.com/apache/arrow/issues/22830)
- [X] [[Java] Add support for skipping decoding of columns/field in Avro converter](https://github.com/apache/arrow/issues/22949)
- [ ] [[Java] Experiment with performance difference of avoiding the use of Avro Decoder](https://github.com/apache/arrow-java/issues/281)
- [X] [[Java] Support logical type encodings from Avro](https://github.com/apache/arrow/issues/22950)
- [ ] [[Java] Avro - Experiment with "compiled" consumer delegates for performance.](https://github.com/apache/arrow-java/issues/280)
- [X] [[JAVA] Avro adapter benchmark only runs once in JMH](https://github.com/apache/arrow/issues/23064)
- [X] [[Java] Extract a common base class for avro converter consumers](https://github.com/apache/arrow/issues/23236)
- [X] [[Java] Avro converter should convert attributes and props to FieldType metadata](https://github.com/apache/arrow/issues/23755)
**Note**: *This issue was originally created as [ARROW-5845](https://issues.apache.org/jira/browse/ARROW-5845). Please see the [migration documentation](https://github.com/apache/arrow/issues/14542) for further details.*
Contributor guide
Research direction
Review the completed subtasks to understand the existing Avro adapter, then inspect the two remaining performance experiments: avoiding the Avro Decoder and using compiled consumer delegates. The issue does not name implementation files, tests, or acceptance criteria for those experiments, so confirm the intended scope with maintainers before starting.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- java
- Domain
- data
- Issue type
- Feature
- Difficulty
- 5/5
- Estimated time
- Over a week
- Activity status
- Stale
- Clarity
- Needs clarification
- Newbie friendliness
- 15/100