Fix PostgreSQL migration script for v5

Resolves #4260

Author: AlbericMartel

spring-batch-core/src/main/resources/org/springframework/batch/core/migration/5.0/migration-postgresql.sql

@@ -1,10 +1,21 @@
 ALTER TABLE BATCH_STEP_EXECUTION ADD CREATE_TIME TIMESTAMP NOT NULL DEFAULT '1970-01-01 00:00:00';
+
 ALTER TABLE BATCH_STEP_EXECUTION ALTER COLUMN START_TIME DROP NOT NULL;
 
 ALTER TABLE BATCH_JOB_EXECUTION_PARAMS DROP COLUMN DATE_VAL;
+
 ALTER TABLE BATCH_JOB_EXECUTION_PARAMS DROP COLUMN LONG_VAL;
+
 ALTER TABLE BATCH_JOB_EXECUTION_PARAMS DROP COLUMN DOUBLE_VAL;
 
-ALTER TABLE BATCH_JOB_EXECUTION_PARAMS MODIFY COLUMN TYPE_CD PARAMETER_TYPE VARCHAR(100);
-ALTER TABLE BATCH_JOB_EXECUTION_PARAMS MODIFY COLUMN KEY_NAME PARAMETER_NAME VARCHAR(100);
-ALTER TABLE BATCH_JOB_EXECUTION_PARAMS MODIFY COLUMN STRING_VAL PARAMETER_VALUE VARCHAR(2500);
+ALTER TABLE BATCH_JOB_EXECUTION_PARAMS ALTER COLUMN TYPE_CD TYPE VARCHAR(100);
+
+ALTER TABLE BATCH_JOB_EXECUTION_PARAMS RENAME TYPE_CD TO PARAMETER_TYPE;
+
+ALTER TABLE BATCH_JOB_EXECUTION_PARAMS ALTER COLUMN KEY_NAME TYPE VARCHAR(100);
+
+ALTER TABLE BATCH_JOB_EXECUTION_PARAMS RENAME KEY_NAME TO PARAMETER_NAME;
+
+ALTER TABLE BATCH_JOB_EXECUTION_PARAMS ALTER COLUMN STRING_VAL TYPE VARCHAR(2500);
+
+ALTER TABLE BATCH_JOB_EXECUTION_PARAMS RENAME STRING_VAL TO PARAMETER_VALUE;