message: SystemStorage does not need to much memory
diff: use std::sync::Arc;
  +use rocksdb::ColumnFamilyDescriptor;
  use serde::{Deserialize, Serialize};
  use crypto::hash::ChainId;
  -use crate::persistent::{BincodeEncoded, KeyValueSchema, KeyValueStoreWithSchema};
  +use crate::persistent::{BincodeEncoded, default_table_options, KeyValueSchema, KeyValueStoreWithSchema};
  use crate::StorageError;
  pub type SystemStorageKv = dyn KeyValueStoreWithSchema<SystemStorage> + Sync + Send;
  @@ -80,11 +81,17 @@ impl SystemStorage {
  }
  }
  -
  impl KeyValueSchema for SystemStorage {
  type Key = String;
  type Value = SystemValue;
  + fn descriptor() -> ColumnFamilyDescriptor {
  + let mut cf_opts = default_table_options();
  + // 1 MB
  + cf_opts.set_write_buffer_size(1024 * 1024);
  + ColumnFamilyDescriptor::new(Self::name(), cf_opts)
  + }
  +
  #[inline]
  fn name() -> &'static str {
  "system_storage"
  