Prevent duplicate creation of the same table (#465)

* Prevent duplicate creation of the same table

* One thread is responsible for creating all the tables.

* Collect all table names.

* spotless:apply

* Each thread creates the table that it is responsible for.

* Each thread creates the table that it is responsible for.

iotdb-2.0/src/main/java/cn/edu/tsinghua/iot/benchmark/iotdb200/ModelStrategy/TableStrategy.java

@@ -96,11 +96,14 @@ public void registerDatabases(Session metaSession, List<TimeseriesSchema> schema
   private void registerTable(Session metaSession, List<TimeseriesSchema> timeseriesSchemas)
       throws TsdbException {
     try {
+      // get all tables
+      Set<String> tableNames = getAllTables(timeseriesSchemas);
+      // register tables
+      DeviceSchema deviceSchema = timeseriesSchemas.get(0).getDeviceSchema();
       HashMap<String, List<String>> tables = new HashMap<>();
-      for (TimeseriesSchema timeseriesSchema : timeseriesSchemas) {
-        DeviceSchema deviceSchema = timeseriesSchema.getDeviceSchema();
+      for (String tableName : tableNames) {
         StringBuilder builder = new StringBuilder();
-        builder.append("create table if not exists ").append(deviceSchema.getTable()).append("(");
+        builder.append("create table if not exists ").append(tableName).append("(");
         for (int i = 0; i < deviceSchema.getSensors().size(); i++) {
           if (i != 0) builder.append(", ");
           builder
@@ -143,6 +146,15 @@ private void registerTable(Session metaSession, List<TimeseriesSchema> timeserie
     }
   }
 
+  public Set<String> getAllTables(List<TimeseriesSchema> schemaList) {
+    Set<String> tableNames = new HashSet<>();
+    for (TimeseriesSchema timeseriesSchema : schemaList) {
+      DeviceSchema schema = timeseriesSchema.getDeviceSchema();
+      tableNames.add(schema.getTable());
+    }
+    return tableNames;
+  }
+
   // region select
 
   @Override