diff --git a/wasm/wasm_executor--1.0.sql b/wasm/wasm_executor--1.0.sql
index f5fc82220c99dc3e17f4a29ea12956c2aa8cd3e1..5215aa7d31c30c6237815775c87056183ed46f0c 100644
--- a/wasm/wasm_executor--1.0.sql
+++ b/wasm/wasm_executor--1.0.sql
@@ -47,6 +47,11 @@ RETURNS int8
 AS 'MODULE_PATHNAME', 'wasm_create_instance_wat'
 LANGUAGE C STRICT;
 
+CREATE FUNCTION wasm_drop_instance(int8)
+RETURNS text
+AS 'MODULE_PATHNAME', 'wasm_drop_instance'
+LANGUAGE C STRICT;
+
 CREATE FUNCTION wasm_invoke_function_0(text, text)
 RETURNS int8
 AS 'MODULE_PATHNAME', 'wasm_invoke_function_0'
@@ -183,7 +188,7 @@ BEGIN
    
     -- Insert the wasm information to gloable table 
     INSERT INTO wasm.instances SELECT id, wasm_file FROM wasm_get_instances() WHERE id = current_instance_id;
-    INSERT INTO wasm.exported_functions SELECT current_instance_id, funcname, inputs, outputs FROM wasm_get_exported_functions(current_instance_id);
+    INSERT INTO wasm.exported_functions SELECT current_instance_id, namespace, funcname, inputs, outputs FROM wasm_get_exported_functions(current_instance_id);
     
     -- Generate functions for each exported functions from the WebAssembly instance.
     FOR
@@ -238,4 +243,40 @@ BEGIN
 
     RETURN current_instance_id;
 END;
+$$ LANGUAGE plpgsql;
+
+
+CREATE OR REPLACE FUNCTION wasm_delete_instance(delete_instance int8) RETURNS text AS $$
+DECLARE
+    instance_module_path text;
+    exported_function RECORD;
+BEGIN
+    -- Create a new instance, and stores its ID in `current_instance_id`.
+    SELECT wasm_drop_instance(delete_instance) INTO STRICT instance_module_path;
+   
+    -- Generate functions for each exported functions from the WebAssembly instance.
+    FOR
+        exported_function
+    IN
+        SELECT
+            namespace,
+            funcname,
+            inputs
+        FROM
+            wasm.exported_functions WHERE instanceid = delete_instance
+    LOOP
+
+        EXECUTE format(
+            'DROP FUNCTION %I_%I(%3$s)',
+            exported_function.namespace, -- 1
+            exported_function.funcname, -- 2
+            exported_function.inputs
+        );
+    END LOOP;
+
+    DELETE FROM wasm.instances WHERE id = delete_instance;
+    DELETE FROM wasm.exported_functions WHERE instanceid = delete_instance;
+
+    RETURN instance_module_path;
+END;
 $$ LANGUAGE plpgsql;
\ No newline at end of file
diff --git a/wasm/wasm_executor.cpp b/wasm/wasm_executor.cpp
index 73b412698929010ec6e0b8c7757048e48294a970..838e406744b3aa7e995411409c560a6453ce7494 100644
--- a/wasm/wasm_executor.cpp
+++ b/wasm/wasm_executor.cpp
@@ -15,6 +15,7 @@ PG_MODULE_MAGIC;
 
 extern "C" Datum wasm_create_instance_wat(PG_FUNCTION_ARGS);
 extern "C" Datum wasm_create_instance(PG_FUNCTION_ARGS);
+extern "C" Datum wasm_drop_instance(PG_FUNCTION_ARGS);
 extern "C" Datum wasm_get_instances(PG_FUNCTION_ARGS);
 extern "C" Datum wasm_get_exported_functions(PG_FUNCTION_ARGS);
 extern "C" Datum wasm_invoke_function_0(PG_FUNCTION_ARGS);
@@ -376,6 +377,34 @@ Datum wasm_create_instance(PG_FUNCTION_ARGS)
     return Int64GetDatum(uuid);
 }
 
+PG_FUNCTION_INFO_V1(wasm_drop_instance);
+Datum wasm_drop_instance(PG_FUNCTION_ARGS) 
+{
+    int64 instanceid = PG_GETARG_INT64(0);
+    Datum module_path;
+    
+    if (!superuser())
+        ereport(ERROR,
+            (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE), (errmsg("wasm_executor: must be system admin to delete wasm instance"))));
+
+    std::map<int64, WasmInstInfo*>::iterator institor = instances.begin();
+    while (institor != instances.end() && institor->first != instanceid) {
+        institor++;
+    }
+    if (institor == instances.end()) {
+        ereport(ERROR, (errmsg("wasm_executor:instance with id=%ld not exist", instanceid)));
+    }
+    module_path = CStringGetTextDatum(institor->second->wasm_file.c_str());
+    instances.erase(institor);
+
+    std::map<int64, std::vector<WasmFuncInfo*>*>::iterator funcitor = exported_functions.begin();
+    while (funcitor != exported_functions.end() && funcitor->first == instanceid) {
+        exported_functions.erase(funcitor++);
+    }
+    
+    return module_path;
+}
+
 PG_FUNCTION_INFO_V1(wasm_get_instances);
 Datum wasm_get_instances(PG_FUNCTION_ARGS) 
 {