Version: 1.3.0

Manage Statistics

Introduction

Starting from 1.0.0, Gravitino introduces statistics of tables and partitions.

This document provides a brief introduction using both Gravitino Java client and REST APIs. If you want to know more about the statistics system in Gravitino, refer to the Javadoc and REST API documentation.

Statistics only support the custom statistics, which names must start with custom-. Gravitino will support built-in statistics in the future.

The query engine uses statistics for cost-based optimization (CBO). Meanwhile, statistics can also be used for metadata action systems to trigger some jobs, such as compaction, data archiving, etc.

Create statistics. And then you can create policies based on statistics. Users can analyze the statistics and policies to decide the next action. For example, you can create a statistic named custom-tableLastModifiedTime to record the last modified time of a table. Then you can create a policy to check if the table hasn't been modified for a long time, and archive the table data to cold storage.

Gravitino doesn't handle the computation of the statistics, you need to compute the statistics and update them to Gravitino. Gravitino can't judge the expiration of the statistics, Ensure the statistics are up-to-date.

Metadata Object Statistic Operations

Update Statistics of Metadata Objects

Update the statistics of a metadata object by providing the statistics key and value. Now only table statistics can be updated.

The request path for REST API is /api/metalakes/{metalake}/objects/{metadataObjectType}/{metadataObjectName}/statistics.

Shell
Java

curl -X PUT -H "Accept: application/vnd.gravitino.v1+json" \
-H "Content-Type: application/json" -d '{
  "updates" : {
      "custom-tableLastModifiedTime": "20250128",
  }
}' http://localhost:8090/api/metalakes/metalake/objects/table/catalog.schema.table/statistics

Table table = ...
Map<String, StatisticValue<?>> updateStatistics = Maps.newHashMap();
updateStatistics.put("custom-k1", StatisticValues.stringValue("v1"));
updateStatistics.put("custom-k2", StatisticValues.stringValue("v2"));
table.updateStatistics(updateStatistics);

List Statistics of Metadata Objects

List all the statistics of a metadata object. Now only table statistics can be listed.

The request path for REST API is /api/metalakes/{metalake}/objects/{metadataObjectType}/{metadataObjectName}/statistics.

Shell
Java

curl -X GET -H "Accept: application/vnd.gravitino.v1+json" \
 -H "Content-Type: application/json" \
 http://localhost:8090/api/metalakes/metalake/objects/table/catalog.schema.table/statistics

Table table = ...
table.listStatistics();

Drop Statistics of Metadata Objects

Drop the statistics of a metadata object by providing the statistics keys. Now only table statistics can be dropped.

The request path for REST API is /api/metalakes/{metalake}/objects/{metadataObjectType}/{metadataObjectName}/statistics.

Shell
Java

curl -X POST -H "Accept: application/vnd.gravitino.v1+json" \
 -H "Content-Type: application/json" -d '{
 "names":["custom-k1"]
}' http://localhost:8090/api/metalakes/metalake/objects/table/catalog.schema.table/statistics

Table table = ...
List<String> statisticsToDrop = Lists.newArrayList("custom-k1");
table.dropStatistics(statisticsToDrop);

Partition Statistics Operations

Update Statistics of Partitions

Update the statistics of a partition by providing the statistics key and value. If the statistics already exist, it will be updated; otherwise, a new statistic will be created.

The request path for REST API is /api/metalakes/{metalake}/objects/table/{metadataObjectName}/statistics/partitions.

Shell
Java

curl -X PUT -H "Accept: application/vnd.gravitino.v1+json" \
-H "Content-Type: application/json" -d '{
  "updates":[{
  "partitionName" : "p0" ,
  "statistics" : {
    "custom-k1" : "v1"
  }
  }]
}' http://localhost:8090/api/metalakes/metalake/objects/table/catalog.schema.table/statistics/partitions

Table table = ...
List<PartitionStatisticsUpdate> statisticsToUpdate = Lists.newArrayList();
Map<String, StatisticValue<?>> stats = Maps.newHashMap();
stats.put("custom-k1", StatisticValues.stringValue("v1"));
stats.put("custom-k2", StatisticValues.stringValue("v2"));
statisticsToUpdate.add(PartitionStatisticsModification.update("p1", stats));
table.updatePartitionStatistics(statisticsToUpdate);

List Statistics of Partitions

List the statistics of specified partitions. Specify a range of partitions by providing the from and to parameters, and whether the range is inclusive using fromInclusive and toInclusive parameters.

The request path for REST API is /api/metalakes/{metalake}/objects/table/{metadataObjectName}/statistics/partitions.

Shell
Java

curl -X GET -H "Accept: application/vnd.gravitino.v1+json" \
 -H "Content-Type: application/json" \
 'http://localhost:8090/api/metalakes/metalake/objects/table/catalog.schema.table/statistics/partitions?from=p0&to=p1&fromInclusive=true&toInclusive=false'

Table table = ...
PartitionRange range = PartitionRange.downTo("p0", PartitionRange.BoundType.CLOSED);
table.listPartitionStatistics(range);

Drop Statistics of Partitions

Drop the statistics of specified partitions by providing the statistics keys.

The request path for REST API is /api/metalakes/{metalake}/objects/table/{metadataObjectName}/statistics/partitions.

Shell
Java

curl -X POST -H "Accept: application/vnd.gravitino.v1+json" \
-H "Content-Type: application/json" -d '{
  "drops" : [{
  "partitionName" : "p0",
  "statisticNames": ["custom-k1"]
  }]
}' http://localhost:8090/api/metalakes/metalake/objects/table/catalog.schema.table/statistics/partitions 

List<PartitionStatisticsDrop> statisticsToDrop = Lists.newArrayList();
statisticsToDrop.add(
    PartitionStatisticsModification.drop("p0", Lists.newArrayList("custom-k1")));

table.dropPartitionStatistics(statisticsToDrop);

Server Configuration

Configuration item	Description	Default value	Required	Since version
`gravitino.stats.partition.storageFactoryClass`	The storage factory class for partition statistics, which is used to store partition statistics in the different storage. The `org.apache.gravitino.stats.storage.MemoryPartitionStatsStorageFactory` can only be used for testing.	`org.apache.gravitino.stats.storage.JdbcPartitionStatisticStorageFactory`	No	1.0.0

JDBC Storage (Default)

Starting from version 1.2.0, Gravitino uses JDBC-based storage as the default partition statistics storage backend. This provides a reliable, production-ready solution that supports multiple database backends:

MySQL (recommended for production)
PostgreSQL
H2 (suitable for testing and development)

To use JDBC storage, configure the following options by adding the prefix gravitino.stats.partition.storageOption.:

Configuration item	Description	Default value	Required	Since version
`gravitino.stats.partition.storageOption.jdbcUrl`	JDBC connection URL (e.g., jdbc:mysql://localhost:3306/gravitino)	None	Yes	1.2.0
`gravitino.stats.partition.storageOption.jdbcUser`	Database username	None	Yes	1.2.0
`gravitino.stats.partition.storageOption.jdbcPassword`	Database password	None	Yes	1.2.0
`gravitino.stats.partition.storageOption.jdbcDriver`	JDBC driver class name	`com.mysql.cj.jdbc.Driver`	No	1.2.0
`gravitino.stats.partition.storageOption.poolMaxSize`	Maximum connection pool size	`10`	No	1.2.0
`gravitino.stats.partition.storageOption.poolMinIdle`	Minimum idle connections in pool	`2`	No	1.2.0
`gravitino.stats.partition.storageOption.connectionTimeoutMs`	Connection timeout in milliseconds	`30000`	No	1.2.0
`gravitino.stats.partition.storageOption.testOnBorrow`	Test connections before use	`true`	No	1.2.0

Example MySQL Configuration:

gravitino.stats.partition.storageFactoryClass = org.apache.gravitino.stats.storage.JdbcPartitionStatisticStorageFactory
gravitino.stats.partition.storageOption.jdbcUrl = jdbc:mysql://localhost:3306/gravitino
gravitino.stats.partition.storageOption.jdbcUser = gravitino
gravitino.stats.partition.storageOption.jdbcPassword = gravitino123
gravitino.stats.partition.storageOption.poolMaxSize = 20

Example PostgreSQL Configuration:

gravitino.stats.partition.storageFactoryClass = org.apache.gravitino.stats.storage.JdbcPartitionStatisticStorageFactory
gravitino.stats.partition.storageOption.jdbcUrl = jdbc:postgresql://localhost:5432/gravitino
gravitino.stats.partition.storageOption.jdbcUser = gravitino
gravitino.stats.partition.storageOption.jdbcPassword = gravitino123
gravitino.stats.partition.storageOption.jdbcDriver = org.postgresql.Driver

Database Schema Setup:

Before using JDBC storage, you need to create the database schema. Schema files are provided for all supported databases:

MySQL: scripts/mysql/schema-${GRAVITINO_VERSION}-mysql.sql
PostgreSQL: scripts/postgresql/schema-${GRAVITINO_VERSION}-postgresql.sql
H2: scripts/h2/schema-${GRAVITINO_VERSION}-h2.sql

For MySQL:

mysql -u root -p < scripts/mysql/schema-${GRAVITINO_VERSION}-mysql.sql

For PostgreSQL:

psql -U postgres -d gravitino -f scripts/postgresql/schema-${GRAVITINO_VERSION}-postgresql.sql

Lance Storage (Alternative)

If you use Lance as the partition statistics storage, you can set the options below, if you have other lance storage options, you can pass it by adding prefix gravitino.stats.partition.storageOption.. For example, if you set an extra property foo to bar for Lance storage option, you can add a configuration item gravitino.stats.partition.storageOption.foo with value bar.

For Lance remote storage, you can refer to the document here.

Configuration item	Description	Default value	Required	Since version
`gravitino.stats.partition.storageOption.location`	The location of Lance files	`${GRAVITINO_HOME}/data/lance`	No	1.0.0
`gravitino.stats.partition.storageOption.maxRowsPerFile`	The maximum rows per file	`1000000`	No	1.0.0
`gravitino.stats.partition.storageOption.maxBytesPerFile`	The maximum bytes per file	`104857600`	No	1.0.0
`gravitino.stats.partition.storageOption.maxRowsPerGroup`	The maximum rows per group	`1000000`	No	1.0.0
`gravitino.stats.partition.storageOption.readBatchSize`	The batch record number when reading	`10000`	No	1.0.0
`gravitino.stats.partition.storageOption.datasetCacheSize`	size of dataset cache for Lance	`0`, It means we don't use the cache	No	1.0.0
`gravitino.stats.partition.storageOption.metadataFileCacheSizeBytes`	The Lance's metadata file cache size	`102400`	No	1.0.0
`gravitino.stats.partition.storageOption.indexCacheSizeBytes`	The Lance's index cache size	`102400`	No	1.0.0
`gravitino.stats.partition.storageOption.maxStatisticsPerUpdate`	Maximum number of statistics allowed per update operation	`100`	No	1.2.0

If you have many tables with a small number of partitions, you should set a smaller metadataFileCacheSizeBytes and indexCacheSizeBytes.

To use Lance storage, configure:

gravitino.stats.partition.storageFactoryClass = org.apache.gravitino.stats.storage.LancePartitionStatisticStorageFactory
gravitino.stats.partition.storageOption.location = /data/lance

Implement a Custom Partition Storage

Implement a custom partition storage by implementing the interface org.apache.gravitino.stats.storage.PartitionStatisticStorageFactory and setting the configuration item gravitino.stats.partition.storageFactoryClass to your class name.

For example:

public class MyPartitionStatsStorageFactory implements PartitionStatisticStorageFactory {
    @Override
    public PartitionStatisticStorage create(Map<String, String> options) {
        // Create your custom PartitionStatsStorage here
        return new MyPartitionStatsStorage(...);
    }
}

public class MyPartitionStatsStorage implements PartitionStatisticStorage {


    @Override
    public void close() {
        // Close your storage here
    }

    @Override
    public void updateStatistics(String metalake, List<MetadataObjectStatisticsUpdate> updates) {
        // Update partition statistics in your storage here
    }

    @Override
    public List<PersistedPartitionStatistics> listStatistics(
            String metalake, MetadataObject metadataObject, PartitionRange range) {
        // List partition statistics from your storage here
        return Maps.newHashMap();
    }

    @Override
    public int dropStatistics(String metalake, List<MetadataObjectStatisticsDrop> drops) {    
        // Drop partition statistics from your storage here
    }
}

Introduction​

Metadata Object Statistic Operations​

Update Statistics of Metadata Objects​

List Statistics of Metadata Objects​

Drop Statistics of Metadata Objects​

Partition Statistics Operations​

Update Statistics of Partitions​

List Statistics of Partitions​

Drop Statistics of Partitions​

Server Configuration​

JDBC Storage (Default)​

Lance Storage (Alternative)​

Implement a Custom Partition Storage​

Introduction

Metadata Object Statistic Operations

Update Statistics of Metadata Objects

List Statistics of Metadata Objects

Drop Statistics of Metadata Objects

Partition Statistics Operations

Update Statistics of Partitions

List Statistics of Partitions

Drop Statistics of Partitions

Server Configuration

JDBC Storage (Default)

Lance Storage (Alternative)

Implement a Custom Partition Storage