diff --git a/README.md b/README.md
index 381e7e2..12fbf64 100644
--- a/README.md
+++ b/README.md
@@ -93,6 +93,7 @@ A proper list contains:
 * `auth`:  authentication options,  `{auth, {basic, #{username => <<"greptime_user">>, password => <<"greptime_pwd">>}}}` for example.
 
 ### Write and datatypes
+The metric name can be a string or binary. If you want to set the database, the metric name can be set in the form of `{dbname, metric}`. The data will be written into `greptime-public` by default.
 
 Write each row by `greptimedb:write/3` function. Every row contains:
 
diff --git a/src/greptimedb.erl b/src/greptimedb.erl
index 3ee35fb..c3e7b25 100644
--- a/src/greptimedb.erl
+++ b/src/greptimedb.erl
@@ -37,13 +37,10 @@ start_client(Options0) ->
             {error, Reason}
     end.
 
-write(#{protocol := Protocol} = Client, Metric, Points) ->
+write(Client, Metric, Points) ->
     try
-        case Protocol of
-            http ->
-                Request = greptimedb_encoder:insert_request(Client, Metric, Points),
-                rpc_call(Client, Request)
-        end
+        Request = greptimedb_encoder:insert_request(Client, Metric, Points),
+        rpc_call(Client, Request)
     catch
         E:R:S ->
             logger:error("[GreptimeDB] write ~0p failed: ~0p ~0p ~0p ~p",
@@ -51,12 +48,9 @@ write(#{protocol := Protocol} = Client, Metric, Points) ->
             {error, R}
     end.
 
-write_stream(#{protocol := Protocol} = Client) ->
+write_stream(Client) ->
     try
-        case Protocol of
-            http ->
-                rpc_write_stream(Client)
-        end
+        rpc_write_stream(Client)
     catch
         E:R:S ->
             logger:error("[GreptimeDB] create write stream failed: ~0p ~0p ~p", [E, R, S]),
@@ -67,11 +61,8 @@ ddl(_Client) ->
     todo.
 
 -spec stop_client(Client :: map()) -> ok | term().
-stop_client(#{pool := Pool, protocol := Protocol}) ->
-    case Protocol of
-        http ->
-            ecpool:stop_sup_pool(Pool)
-    end.
+stop_client(#{pool := Pool}) ->
+    ecpool:stop_sup_pool(Pool).
 
 %%%===================================================================
 %%% Internal functions
diff --git a/src/greptimedb_encoder.erl b/src/greptimedb_encoder.erl
index ba9cbf4..a5a6771 100644
--- a/src/greptimedb_encoder.erl
+++ b/src/greptimedb_encoder.erl
@@ -17,10 +17,9 @@
 -export([insert_request/3]).
 
 -define(TS_COLUMN, <<"greptime_timestamp">>).
--define(DEFAULT_CATALOG, "greptime").
--define(DEFAULT_SCHEMA, "public").
+-define(DEFAULT_DBNAME, "greptime-public").
 
-insert_request(#{cli_opts := Options} = _Client, {Catalog, Schema, Table}, Points) ->
+insert_request(#{cli_opts := Options} = _Client, {DbName, Table}, Points) ->
     RowCount = length(Points),
     Columns =
         lists:map(fun(Column) -> pad_null_mask(Column, RowCount) end, collect_columns(Points)),
@@ -28,10 +27,9 @@ insert_request(#{cli_opts := Options} = _Client, {Catalog, Schema, Table}, Point
     Header =
         case AuthHeader of
             {} ->
-                #{catalog => Catalog, schema => Schema};
+                #{dbname => DbName};
             Scheme ->
-                #{catalog => Catalog,
-                  schema => Schema,
+                #{dbname => DbName,
                   authorization => #{auth_scheme => Scheme}}
         end,
 
@@ -42,7 +40,7 @@ insert_request(#{cli_opts := Options} = _Client, {Catalog, Schema, Table}, Point
            row_count => RowCount}},
     #{header => Header, request => Request};
 insert_request(Client, Table, Points) ->
-    insert_request(Client, {?DEFAULT_CATALOG, ?DEFAULT_SCHEMA, Table}, Points).
+    insert_request(Client, {?DEFAULT_DBNAME, Table}, Points).
 
 %%%===================================================================
 %%% Internal functions
diff --git a/test/greptimedb_SUITE.erl b/test/greptimedb_SUITE.erl
index d120683..22a443e 100644
--- a/test/greptimedb_SUITE.erl
+++ b/test/greptimedb_SUITE.erl
@@ -52,12 +52,10 @@ t_collect_columns(_) ->
     Request = greptimedb_encoder:insert_request(Client, Metric, Points),
     case Request of
         #{header :=
-              #{catalog := Catalog,
-                schema := Schema,
+              #{dbname := DbName,
                 authorization := Auth},
           request := {insert, #{columns := Columns}}} ->
-            ?assertEqual(Catalog, "greptime"),
-            ?assertEqual(Schema, "public"),
+            ?assertEqual(DbName, "greptime-public"),
             ?assertEqual(8, length(Columns)),
             ?assertEqual(Auth, #{auth_scheme => AuthInfo}),