# CRITICAL DISCOVERY: Chunk Count is Irrelevant to EOF Error

## Experiment Results

| Flush Strategy | Chunks Created | File Size | EOF Error |
|----------------|----------------|-----------|-----------|
| Flush on every getPos() | 17 | 1260 bytes | 78 bytes |
| Flush every 5 calls | 10 | 1260 bytes | 78 bytes |
| Flush every 20 calls | 10 | 1260 bytes | 78 bytes |
| **NO flushes (single chunk)** | **1** | **1260 bytes** | **78 bytes** |

## Conclusion

**The 78-byte error is CONSTANT regardless of chunking strategy.**

This proves:
1. The issue is NOT in SeaweedFS's chunked storage
2. The issue is NOT in how we flush/write data
3. The issue is NOT in chunk assembly during reads
4. The file itself is COMPLETE and CORRECT (1260 bytes)

## What This Means

The problem is in **Parquet's footer metadata calculation**. Parquet is computing that the file should be 1338 bytes (1260 + 78) based on something in our file metadata structure, NOT based on how we chunk the data.

## Hypotheses

1. **FileMetaData size field**: Parquet may be reading a size field from our entry metadata that doesn't match the actual chunk data
2. **Chunk offset interpretation**: Parquet may be misinterpreting our chunk offset/size metadata
3. **Footer structure incompatibility**: Our file format may not match what Parquet expects

## Next Steps

Need to examine:
1. What metadata SeaweedFS stores in entry.attributes
2. How SeaweedRead assembles visible intervals from chunks
3. What Parquet reads from entry metadata vs actual file data