Implementation:Apache Shardingsphere StatisticsPersistService Persist

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

Overview

StatisticsPersistService manages the persistence lifecycle of ShardingSphere statistics data at database, schema, and table levels through a hierarchical repository.

Description

StatisticsPersistService is a final class in the mode/core module responsible for loading, persisting, updating, and deleting ShardingSphereStatistics. It delegates table-level row data operations to TableRowDataPersistService and uses NodePathGenerator to resolve hierarchical statistics paths in the underlying PersistRepository. The class traverses database/schema/table hierarchies when loading statistics, filtering against existing metadata to ensure consistency.

Usage

Use this service when you need to load statistics from the persist repository on startup, persist schema-level statistics after collection, apply incremental updates (adds, updates, deletes) via AlteredDatabaseStatistics, or remove all statistics for a dropped database.

Code Reference

Source Location

• Repository: Apache_Shardingsphere
• File: StatisticsPersistService.java
• Lines: 1-146

Signature

public final class StatisticsPersistService {

    public StatisticsPersistService(final PersistRepository repository)

    public ShardingSphereStatistics load(final ShardingSphereMetaData metaData)

    public void persist(final ShardingSphereDatabase database, final String schemaName,
                        final SchemaStatistics schemaStatistics)

    public void update(final AlteredDatabaseStatistics alteredDatabaseStatistics)

    public void delete(final String databaseName)
}

Import

import org.apache.shardingsphere.mode.metadata.persist.statistics.StatisticsPersistService;

I/O Contract

Inputs

Name	Type	Required	Description
repository	PersistRepository	Yes	The underlying persist repository for reading/writing data
metaData	ShardingSphereMetaData	Yes	Metadata used to filter and validate statistics during load
database	ShardingSphereDatabase	Yes	Database context for persist operations
schemaName	String	Yes	Schema name for persist operations
schemaStatistics	SchemaStatistics	Yes	Schema-level statistics to persist
alteredDatabaseStatistics	AlteredDatabaseStatistics	Yes	Diff-based statistics containing added, updated, and deleted rows
databaseName	String	Yes	Database name for delete operations

Outputs

Name	Type	Description
statistics	ShardingSphereStatistics	Loaded statistics hierarchy containing database/schema/table data

Usage Examples

// Load statistics from repository
StatisticsPersistService service = new StatisticsPersistService(repository);
ShardingSphereStatistics statistics = service.load(metaData);

// Persist schema statistics
service.persist(database, "public", schemaStatistics);

// Apply incremental updates
service.update(alteredDatabaseStatistics);

// Delete all statistics for a database
service.delete("my_database");

Related Pages

• Principle:Apache_Shardingsphere_Metadata_Repository_Persistence