# The `GC` Process
+ On compaction completed, update discardable size and calculate `GC` score
+ Select multiple `BLOB` files from the maximum score to minimum score as candidate files
+ Iterate all `KV` pairs in the candidate `BLOB` files, merge and sort all active values to a new `BLOB` file
+ Rewrite all valid `key-index` pairs to `LSM-Tree`
+ Physically delete the old `BLOB` files once no snapshot is referring to them

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