ajayky-os opened a new issue, #16283:
URL: https://github.com/apache/iceberg/issues/16283
### Apache Iceberg version
main (development)
### Query engine
Spark
### Please describe the bug 🐞
**Description**
When executing Spark queries on Iceberg tables stored in cloud storage
(specifically GCS and S3). The root cause is that SerializableFileIOWithSize
fails to override the newInputFile(String path, long length) method, causing
the file length property to be dropped during Spark execution.
**Root Cause**
When an Iceberg reader on an executor attempts to open a file using a
DataFile object or an explicit length, the Java runtime falls back to the
default implementation in the FileIO interface:
```
// api/src/main/java/org/apache/iceberg/io/FileIO.java
default InputFile newInputFile(String path, long length) {
return newInputFile(path); // <--- Length property is discarded here!
}
```
Because SerializableFileIOWithSize does not override this, the length is
lost before the call reaches the underlying IO implementation (e.g.,
GCSFileIO).
**Impact**
When the length is dropped, IO implementations like GCSFileIO instantiate
GCSInputStream with a null file size.
When reading columnar formats (Parquet/ORC), Iceberg needs the file size to
locate the footer (readTail). If the size is unknown, the IO driver is forced
to execute a synchronous, blocking metadata API call (e.g., storage.get() in
GCS) to determine the size.
This results in tens of thousands of unnecessary GetObjectMetadata calls,
significantly degrading query performance and increases cost as well. In local
testing, fixing this restored performance gap.
### Willingness to contribute
- [ ] I can contribute a fix for this bug independently
- [x] I would be willing to contribute a fix for this bug with guidance from
the Iceberg community
- [ ] I cannot contribute a fix for this bug at this time
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