Add `used` memory size to `FairSpillPool`
Open
enhancement
- Dominant language
- Rust
- Stars
- 9.3k
- Forks
- 2.4k
- Avg merge
- 3d 7h
- Merged PRs (30d)
- 344
Description
### Is your feature request related to a problem or challenge?
Currently, both `GreedyMemoryPool` and `UnboundedMemoryPool` track `used` memory size in addition to `pool_size`. Adding used memory size to `FairSpillPool` can also be useful. This is follow-up effort for https://github.com/apache/datafusion/pull/20387#discussion_r3109645177.
### Describe the solution you'd like
To add `used` memory size to `FairSpillPool`.
### Describe alternatives you've considered
_No response_
### Additional context
_No response_
Contributor guide
Assessment
This issue has not been assessed yet.