Update README.md

README.md

@@ -34,3 +34,23 @@ There are 2 main scenarios:
 
 - opendb loads stored rocksdb configuration and starts with it
 - opendb overrides options which explicitly specified in appOpts (app.toml)
+
+### List of reported rocksdb metrics:
+
+#### Key Subsystem
+
+| Name                | Subsystem | Docs |
+| ------------------- | --------- | ---- |
+| number_keys_written | Key       |      |
+| number_keys_read    | Key       |      |
+| number_keys_updated | Key       |      |
+| estimate_num_keys   | Key       | estimated number of total keys in the active and unflushed immutable memtables and storage |
+| estimate_num_keys   | File      |      |
+| estimate_num_keys   | File      |      |
+
+#### File Subsystem
+
+| Name                | Docs    |
+| --------            | ------- |
+| number_file_opens   |         |
+| number_file_errors  |         |