Change default to recalc

priv/riak_kv.schema

@@ -1471,23 +1471,30 @@
     {commented, 900}
 ]}.
 
-%% @doc Enable the `recalc` compaction strategy within the leveled backend in
-%% riak.  The default (when disabled) is `retain`, but this will leave
-%% uncollected garbage within the, journal. 
-%% It is now recommended from Riak KV 2.9.2 to consider the `recalc` strategy.
+%% @doc Enable the `recalc` compaction strategy
+%% This is relevant only to the leveled backend.  If disabled the `retain`
+%% strategy will be used, but this will leave uncollected garbage within the
+%% journal.
+%%
+%% The default `retain` strategy retains a history of key changes in the
+%% journal, whereas the `recalc` strategy discards that history, but will redo
+%% a diff_index_specs calculation when reloading each object.
+%%
+%% It is recommended to use the `recalc` strategy.
+%%
 %% This strategy has a side effect of slower startups, and slower recovery
 %% from a wiped ledger - but it will not keep an overhead of garbage within
 %% the Journal.
+%%
 %% It should be possible to move from `retain` to `recalc` via configuration
 %% change.  However, it is not possible to switch from `recalc` back to
-%% `retain`.  This switch can only be made for new nodes receiving data
-%% through riak transfers (not inheriting data on disk).
-%% The default `retain` strategy retains a history of key changes in the
-%% journal, whereas the `recalc` strategy discards that history, but will redo
-%% a diff_index_specs calculation when reloading each object.
+%% `retain` just by reverting the config.  This switch can only be made for
+%% new nodes receiving data through riak transfers (not inheriting data on
+%% disk) - so a rolling `riak admin cluster replace` would be required to
+%% revert to `retain`.
 {mapping, "leveled_reload_recalc", "riak_kv.leveled_reload_recalc", [
     {datatype, {flag, enabled, disabled}},
-    {default, disabled},
+    {default, enabled},
     {commented, enabled}
 ]}.