优化统计MySQL大表总数，改为系统表查询

dbsyncer-connector/dbsyncer-connector-mysql/src/main/java/org/dbsyncer/connector/mysql/MySQLConnector.java

@@ -9,13 +9,16 @@ import org.dbsyncer.connector.mysql.schema.MySQLDateValueMapper;
 import org.dbsyncer.connector.mysql.schema.MySQLSchemaResolver;
 import org.dbsyncer.connector.mysql.storage.MySQLStorageService;
 import org.dbsyncer.connector.mysql.validator.MySQLConfigValidator;
+import org.dbsyncer.sdk.config.CommandConfig;
 import org.dbsyncer.sdk.connector.ConfigValidator;
 import org.dbsyncer.sdk.connector.database.AbstractDatabaseConnector;
 import org.dbsyncer.sdk.constant.DatabaseConstant;
 import org.dbsyncer.sdk.enums.ListenerTypeEnum;
+import org.dbsyncer.sdk.enums.TableTypeEnum;
 import org.dbsyncer.sdk.listener.DatabaseQuartzListener;
 import org.dbsyncer.sdk.listener.Listener;
 import org.dbsyncer.sdk.model.PageSql;
+import org.dbsyncer.sdk.model.Table;
 import org.dbsyncer.sdk.plugin.ReaderContext;
 import org.dbsyncer.sdk.schema.SchemaResolver;
 import org.dbsyncer.sdk.storage.StorageService;
@@ -138,6 +141,17 @@ public final class MySQLConnector extends AbstractDatabaseConnector {
         return newCursors;
     }
 
+    @Override
+    protected String getQueryCountSql(CommandConfig commandConfig, List<String> primaryKeys, String schema, String queryFilterSql) {
+        final Table table = commandConfig.getTable();
+        if (StringUtil.isNotBlank(queryFilterSql) || TableTypeEnum.isView(table.getType())) {
+            return super.getQueryCountSql(commandConfig, primaryKeys, schema, queryFilterSql);
+        }
+
+        // 从系统表查询
+        return String.format("SELECT TABLE_ROWS FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_NAME = '%s' LIMIT 1", table.getName());
+    }
+
     @Override
     public boolean enableCursor() {
         return true;

dbsyncer-parser/src/main/java/org/dbsyncer/parser/model/Task.java

@@ -16,9 +16,6 @@ public class Task {
 
     private long endTime;
 
-    public Task() {
-    }
-
     public Task(String id) {
         this.id = id;
         this.state = StateEnum.RUNNING;