Implementation:Apache Shardingsphere StatisticsManager Manage

Knowledge Sources	Apache_Shardingsphere
Domains	Mode_Management, Statistics
Last Updated	2026-02-10 00:00 GMT

Overview

Synchronized manager for in-memory statistics data at database, schema, table, and row levels.

Description

StatisticsManager manages the lifecycle of statistics data held in ShardingSphereStatistics. It provides synchronized methods to add and drop database, schema, and table statistics, as well as alter and delete individual row statistics using YamlRowStatistics. All operations atomically update the statistics within MetaDataContexts.

Usage

Accessed via MetaDataContextManager.getStatisticsManager() to apply statistics changes triggered by cluster events or local operations.

Code Reference

Source Location

• Repository: Apache_Shardingsphere
• File: StatisticsManager.java
• Lines: 1-160

Signature

@RequiredArgsConstructor
public final class StatisticsManager {

    private final MetaDataContexts metaDataContexts;

    public synchronized void addDatabase(String databaseName);
    public synchronized void dropDatabase(String databaseName);
    public synchronized void addSchema(String databaseName, String schemaName);
    public synchronized void dropSchema(String databaseName, String schemaName);
    public synchronized void addTable(String databaseName, String schemaName, String tableName);
    public synchronized void dropTable(String databaseName, String schemaName, String tableName);
    public synchronized void alterRowData(String databaseName, String schemaName, String tableName,
        String uniqueKey, YamlRowStatistics yamlRowStatistics);
    public synchronized void deleteRowData(String databaseName, String schemaName, String tableName,
        String uniqueKey);
}

Import

import org.apache.shardingsphere.mode.metadata.manager.statistics.StatisticsManager;

I/O Contract

Inputs

Name	Type	Required	Description
databaseName	String	Yes	Target database
schemaName	String	Varies	Target schema
tableName	String	Varies	Target table
uniqueKey	String	Varies	Row unique identifier
yamlRowStatistics	YamlRowStatistics	Varies	Row data to alter

Outputs

Name	Type	Description
void	—	Side effect: updates in-memory statistics

Usage Examples

StatisticsManager manager = metaDataContextManager.getStatisticsManager();

// Track a new database in statistics
manager.addDatabase("my_database");
manager.addSchema("my_database", "public");
manager.addTable("my_database", "public", "t_order");

// Alter row data
manager.alterRowData("my_database", "public", "t_order", "row_1", yamlRow);

Related Pages

• Principle:Apache_Shardingsphere_Cluster_Metadata_Synchronization