@Override
    public synchronized void close() {
        // close open iterators
        final HashSet<KeyValueIterator<Bytes, byte[]>> iterators;
        synchronized (openIterators) {
            iterators = new HashSet<>(openIterators);
            openIterators.clear();
        }
        if (iterators.size() != 0) {
            log.warn("Closing {} open iterators for store {}", iterators.size(), name);
            for (final KeyValueIterator<Bytes, byte[]> iterator : iterators) {
                iterator.close();
            }
        }
    }
This "logical segment" is a segment which shares its underlying physical store with other
logical segments. Each segment uses a unique, fixed-length key prefix derived from the
segment ID when writing to the shared physical store. In other words, a logical segment
stores a key into a shared physical store by prepending the key with a prefix (unique to
the specific logical segment), and storing the combined key into the physical store.
streams/src/main/java/org/apache/kafka/streams/state/internals/LogicalKeyValueSegment.java