Adding indexes to improve performance of entity retrieval and fixing a sytax error in the SQL query used to retrieve activities

components/device-mgt/org.wso2.carbon.device.mgt.core/src/main/java/org/wso2/carbon/device/mgt/core/operation/mgt/dao/impl/GenericOperationDAOImpl.java

@@ -368,7 +368,7 @@ public class GenericOperationDAOImpl implements OperationDAO {
 //            }
 
             String sql = "SELECT dte.ENROLMENT_ID, oor.OPERATION_ID, oor.OP_RES_ID, oor.OPERATION_TYPE, " +
-                    "oor.OPERATION_CODE, oor.OPERATION_RESPONSE, oor.CREATED_TIMESTAMP dte.DEVICE_TYPE, dte.DEVICE_IDENTIFICATION, " +
+                    "oor.OPERATION_CODE, oor.OPERATION_RESPONSE, oor.CREATED_TIMESTAMP, dte.DEVICE_TYPE, dte.DEVICE_IDENTIFICATION, " +
                     "oor.RECEIVED_TIMESTAMP, eom.UPDATED_TIMESTAMP, eom.STATUS FROM (SELECT d.DEVICE_IDENTIFICATION, " +
                     "t.NAME AS DEVICE_TYPE, e.ID AS ENROLMENT_ID FROM DM_DEVICE d INNER JOIN DM_DEVICE_TYPE t " +
                     "ON d.DEVICE_TYPE_ID = t.ID INNER JOIN DM_ENROLMENT e ON d.ID = e.DEVICE_ID WHERE " +

features/device-mgt/org.wso2.carbon.device.mgt.server.feature/src/main/resources/dbscripts/cdm/mysql.sql

@@ -5,7 +5,8 @@ CREATE TABLE IF NOT EXISTS DM_DEVICE_TYPE (
      SHARED_WITH_ALL_TENANTS BOOLEAN NOT NULL DEFAULT FALSE,
      PRIMARY KEY (ID)
 )ENGINE = InnoDB;
-CREATE INDEX device_type_name ON DM_DEVICE_TYPE (NAME);
+
+CREATE INDEX IDX_DEVICE_TYPE ON DM_DEVICE_TYPE (NAME);
 
 CREATE TABLE IF NOT EXISTS DM_DEVICE (
      ID                    INTEGER AUTO_INCREMENT NOT NULL,
@@ -20,13 +21,14 @@ CREATE TABLE IF NOT EXISTS DM_DEVICE (
      REFERENCES DM_DEVICE_TYPE (ID) ON DELETE NO ACTION ON UPDATE NO ACTION
 )ENGINE = InnoDB;
 
+CREATE INDEX IDX_DM_DEVICE ON DM_DEVICE(TENANT_ID, DEVICE_TYPE_ID);
 
 CREATE TABLE IF NOT EXISTS DM_OPERATION (
     ID INTEGER AUTO_INCREMENT NOT NULL,
-    TYPE VARCHAR(50) NOT NULL,
+    TYPE VARCHAR(20) NOT NULL,
     CREATED_TIMESTAMP TIMESTAMP NOT NULL,
     RECEIVED_TIMESTAMP TIMESTAMP NULL,
-    OPERATION_CODE VARCHAR(1000) NOT NULL,
+    OPERATION_CODE VARCHAR(50) NOT NULL,
     PRIMARY KEY (ID)
 )ENGINE = InnoDB;
 
@@ -83,6 +85,8 @@ CREATE TABLE IF NOT EXISTS DM_ENROLMENT (
     DM_DEVICE (ID) ON DELETE NO ACTION ON UPDATE NO ACTION
 )ENGINE = InnoDB;
 
+CREATE INDEX IDX_ENROLMENT_FK_DEVICE_ID ON DM_ENROLMENT(DEVICE_ID);
+CREATE INDEX IDX_ENROLMENT_DEVICE_ID_TENANT_ID ON DM_ENROLMENT(DEVICE_ID, TENANT_ID);
 
 CREATE TABLE IF NOT EXISTS DM_ENROLMENT_OP_MAPPING (
     ID INTEGER AUTO_INCREMENT NOT NULL,
@@ -98,6 +102,9 @@ CREATE TABLE IF NOT EXISTS DM_ENROLMENT_OP_MAPPING (
     DM_OPERATION (ID) ON DELETE NO ACTION ON UPDATE NO ACTION
 )ENGINE = InnoDB;
 
+CREATE INDEX IDX_ENROLMENT_OP_MAPPING ON DM_ENROLMENT_OP_MAPPING (UPDATED_TIMESTAMP);
+CREATE INDEX IDX_EN_OP_MAPPING_EN_ID ON DM_ENROLMENT_OP_MAPPING(ENROLMENT_ID);
+CREATE INDEX IDX_EN_OP_MAPPING_OP_ID ON DM_ENROLMENT_OP_MAPPING(OPERATION_ID);
 
 CREATE TABLE IF NOT EXISTS DM_DEVICE_OPERATION_RESPONSE (
     ID INTEGER AUTO_INCREMENT NOT NULL,