Catalog Integration

/**
 * Catalog implementation for Hive metastore integration
 * Provides unified metadata management for databases, tables, partitions, and functions
 */
public class HiveCatalog extends AbstractCatalog {
    
    /**
     * Creates a new HiveCatalog instance
     * @param catalogName Name of the catalog in Flink
     * @param defaultDatabase Default database name (typically "default")
     * @param hiveConfDir Path to directory containing hive-site.xml
     * @param hiveVersion Hive version for compatibility (e.g., "3.1.2")
     */
    public HiveCatalog(String catalogName, String defaultDatabase, 
                       String hiveConfDir, String hiveVersion);
    
    /**
     * Creates HiveCatalog with additional Hadoop configuration
     * @param catalogName Name of the catalog in Flink
     * @param defaultDatabase Default database name  
     * @param hiveConfDir Path to Hive configuration directory
     * @param hadoopConfDir Path to Hadoop configuration directory
     * @param hiveVersion Hive version for compatibility
     */
    public HiveCatalog(String catalogName, String defaultDatabase,
                       String hiveConfDir, String hadoopConfDir, String hiveVersion);
    
    /**
     * Opens the catalog and establishes metastore connection
     * @throws CatalogException if connection fails
     */
    public void open() throws CatalogException;
    
    /**
     * Closes the catalog and releases resources
     * @throws CatalogException if close operation fails
     */
    public void close() throws CatalogException;
    
    // Database Operations
    
    /**
     * Lists all databases in the catalog
     * @return List of database names
     * @throws CatalogException if operation fails
     */
    public List<String> listDatabases() throws CatalogException;
    
    /**
     * Checks if a database exists
     * @param databaseName Name of the database
     * @return True if database exists, false otherwise
     * @throws CatalogException if operation fails
     */
    public boolean databaseExists(String databaseName) throws CatalogException;
    
    /**
     * Gets database metadata
     * @param databaseName Name of the database
     * @return CatalogDatabase containing metadata
     * @throws DatabaseNotExistException if database doesn't exist
     * @throws CatalogException if operation fails
     */
    public CatalogDatabase getDatabase(String databaseName) 
        throws DatabaseNotExistException, CatalogException;
    
    /**
     * Creates a new database
     * @param databaseName Name of the database to create
     * @param database Database metadata
     * @param ignoreIfExists Whether to ignore if database already exists
     * @throws DatabaseAlreadyExistException if database exists and ignoreIfExists is false
     * @throws CatalogException if operation fails
     */
    public void createDatabase(String databaseName, CatalogDatabase database, boolean ignoreIfExists)
        throws DatabaseAlreadyExistException, CatalogException;
    
    /**
     * Drops an existing database
     * @param databaseName Name of the database to drop
     * @param ignoreIfNotExists Whether to ignore if database doesn't exist
     * @param cascade Whether to drop tables in the database
     * @throws DatabaseNotExistException if database doesn't exist and ignoreIfNotExists is false
     * @throws DatabaseNotEmptyException if database is not empty and cascade is false
     * @throws CatalogException if operation fails
     */
    public void dropDatabase(String databaseName, boolean ignoreIfNotExists, boolean cascade)
        throws DatabaseNotExistException, DatabaseNotEmptyException, CatalogException;
    
    // Table Operations
    
    /**
     * Lists all tables in a database
     * @param databaseName Name of the database
     * @return List of table names
     * @throws DatabaseNotExistException if database doesn't exist
     * @throws CatalogException if operation fails
     */
    public List<String> listTables(String databaseName) 
        throws DatabaseNotExistException, CatalogException;
    
    /**
     * Checks if a table exists
     * @param tablePath Path identifying the table (database.table)
     * @return True if table exists, false otherwise
     * @throws CatalogException if operation fails
     */
    public boolean tableExists(ObjectPath tablePath) throws CatalogException;
    
    /**
     * Gets table metadata
     * @param tablePath Path identifying the table
     * @return CatalogBaseTable containing metadata
     * @throws TableNotExistException if table doesn't exist
     * @throws CatalogException if operation fails
     */
    public CatalogBaseTable getTable(ObjectPath tablePath) 
        throws TableNotExistException, CatalogException;
    
    /**
     * Creates a new table
     * @param tablePath Path identifying the table
     * @param table Table metadata
     * @param ignoreIfExists Whether to ignore if table already exists
     * @throws TableAlreadyExistException if table exists and ignoreIfExists is false
     * @throws DatabaseNotExistException if database doesn't exist
     * @throws CatalogException if operation fails
     */
    public void createTable(ObjectPath tablePath, CatalogBaseTable table, boolean ignoreIfExists)
        throws TableAlreadyExistException, DatabaseNotExistException, CatalogException;
    
    /**
     * Drops an existing table
     * @param tablePath Path identifying the table
     * @param ignoreIfNotExists Whether to ignore if table doesn't exist
     * @throws TableNotExistException if table doesn't exist and ignoreIfNotExists is false
     * @throws CatalogException if operation fails
     */
    public void dropTable(ObjectPath tablePath, boolean ignoreIfNotExists)
        throws TableNotExistException, CatalogException;
    
    // Partition Operations
    
    /**
     * Lists all partitions of a table
     * @param tablePath Path identifying the table
     * @return List of partition specifications
     * @throws TableNotExistException if table doesn't exist
     * @throws TableNotPartitionedException if table is not partitioned
     * @throws CatalogException if operation fails
     */
    public List<CatalogPartitionSpec> listPartitions(ObjectPath tablePath)
        throws TableNotExistException, TableNotPartitionedException, CatalogException;
    
    /**
     * Gets partition metadata
     * @param tablePath Path identifying the table
     * @param partitionSpec Partition specification
     * @return CatalogPartition containing metadata
     * @throws PartitionNotExistException if partition doesn't exist
     * @throws CatalogException if operation fails
     */
    public CatalogPartition getPartition(ObjectPath tablePath, CatalogPartitionSpec partitionSpec)
        throws PartitionNotExistException, CatalogException;
    
    /**
     * Checks if a partition exists
     * @param tablePath Path identifying the table
     * @param partitionSpec Partition specification
     * @return True if partition exists, false otherwise
     * @throws CatalogException if operation fails
     */
    public boolean partitionExists(ObjectPath tablePath, CatalogPartitionSpec partitionSpec)
        throws CatalogException;
    
    // Function Operations
    
    /**
     * Lists all functions in a database
     * @param databaseName Name of the database
     * @return List of function names
     * @throws DatabaseNotExistException if database doesn't exist
     * @throws CatalogException if operation fails
     */
    public List<String> listFunctions(String databaseName) 
        throws DatabaseNotExistException, CatalogException;
    
    /**
     * Gets function metadata
     * @param functionPath Path identifying the function
     * @return CatalogFunction containing metadata
     * @throws FunctionNotExistException if function doesn't exist
     * @throws CatalogException if operation fails
     */
    public CatalogFunction getFunction(ObjectPath functionPath)
        throws FunctionNotExistException, CatalogException;
    
    /**
     * Checks if a function exists
     * @param functionPath Path identifying the function
     * @return True if function exists, false otherwise
     * @throws CatalogException if operation fails
     */
    public boolean functionExists(ObjectPath functionPath) throws CatalogException;
    
    /**
     * Creates a new function
     * @param functionPath Path identifying the function
     * @param function Function metadata
     * @param ignoreIfExists Whether to ignore if function already exists
     * @throws FunctionAlreadyExistException if function exists and ignoreIfExists is false
     * @throws DatabaseNotExistException if database doesn't exist
     * @throws CatalogException if operation fails
     */
    public void createFunction(ObjectPath functionPath, CatalogFunction function, boolean ignoreIfExists)
        throws FunctionAlreadyExistException, DatabaseNotExistException, CatalogException;
    
    /**
     * Drops an existing function
     * @param functionPath Path identifying the function
     * @param ignoreIfNotExists Whether to ignore if function doesn't exist
     * @throws FunctionNotExistException if function doesn't exist and ignoreIfNotExists is false
     * @throws CatalogException if operation fails
     */
    public void dropFunction(ObjectPath functionPath, boolean ignoreIfNotExists)
        throws FunctionNotExistException, CatalogException;
    
    /**
     * Alters an existing function
     * @param functionPath Path identifying the function
     * @param newFunction New function metadata
     * @param ignoreIfNotExists Whether to ignore if function doesn't exist
     * @throws FunctionNotExistException if function doesn't exist and ignoreIfNotExists is false
     * @throws CatalogException if operation fails
     */
    public void alterFunction(ObjectPath functionPath, CatalogFunction newFunction, boolean ignoreIfNotExists)
        throws FunctionNotExistException, CatalogException;
    
    // Additional Table Operations
    
    /**
     * Lists all views in a database
     * @param databaseName Name of the database
     * @return List of view names
     * @throws DatabaseNotExistException if database doesn't exist
     * @throws CatalogException if operation fails
     */
    public List<String> listViews(String databaseName) 
        throws DatabaseNotExistException, CatalogException;
    
    /**
     * Renames an existing table
     * @param tablePath Current path of the table
     * @param newTableName New name for the table
     * @param ignoreIfNotExists Whether to ignore if table doesn't exist
     * @throws TableNotExistException if table doesn't exist and ignoreIfNotExists is false
     * @throws TableAlreadyExistException if new table name already exists
     * @throws CatalogException if operation fails
     */
    public void renameTable(ObjectPath tablePath, String newTableName, boolean ignoreIfNotExists)
        throws TableNotExistException, TableAlreadyExistException, CatalogException;
    
    /**
     * Alters an existing table
     * @param tablePath Path identifying the table
     * @param newCatalogTable New table metadata
     * @param ignoreIfNotExists Whether to ignore if table doesn't exist
     * @throws TableNotExistException if table doesn't exist and ignoreIfNotExists is false
     * @throws CatalogException if operation fails
     */
    public void alterTable(ObjectPath tablePath, CatalogBaseTable newCatalogTable, boolean ignoreIfNotExists)
        throws TableNotExistException, CatalogException;
    
    /**
     * Alters an existing database
     * @param databaseName Name of the database
     * @param newDatabase New database metadata
     * @param ignoreIfNotExists Whether to ignore if database doesn't exist
     * @throws DatabaseNotExistException if database doesn't exist and ignoreIfNotExists is false
     * @throws CatalogException if operation fails
     */
    public void alterDatabase(String databaseName, CatalogDatabase newDatabase, boolean ignoreIfNotExists)
        throws DatabaseNotExistException, CatalogException;
    
    // Additional Partition Operations
    
    /**
     * Lists partitions matching a partial partition specification
     * @param tablePath Path identifying the table
     * @param partitionSpec Partial partition specification
     * @return List of matching partition specifications
     * @throws TableNotExistException if table doesn't exist
     * @throws TableNotPartitionedException if table is not partitioned
     * @throws PartitionSpecInvalidException if partition spec is invalid
     * @throws CatalogException if operation fails
     */
    public List<CatalogPartitionSpec> listPartitions(ObjectPath tablePath, CatalogPartitionSpec partitionSpec)
        throws TableNotExistException, TableNotPartitionedException, PartitionSpecInvalidException, CatalogException;
    
    /**
     * Lists partitions matching filter expressions
     * @param tablePath Path identifying the table
     * @param expressions Filter expressions
     * @return List of matching partition specifications
     * @throws TableNotExistException if table doesn't exist
     * @throws TableNotPartitionedException if table is not partitioned
     * @throws CatalogException if operation fails
     */
    public List<CatalogPartitionSpec> listPartitionsByFilter(ObjectPath tablePath, List<Expression> expressions)
        throws TableNotExistException, TableNotPartitionedException, CatalogException;
    
    /**
     * Creates a new partition
     * @param tablePath Path identifying the table
     * @param partitionSpec Partition specification
     * @param partition Partition metadata
     * @param ignoreIfExists Whether to ignore if partition already exists
     * @throws TableNotExistException if table doesn't exist
     * @throws TableNotPartitionedException if table is not partitioned
     * @throws PartitionSpecInvalidException if partition spec is invalid
     * @throws PartitionAlreadyExistsException if partition exists and ignoreIfExists is false
     * @throws CatalogException if operation fails
     */
    public void createPartition(ObjectPath tablePath, CatalogPartitionSpec partitionSpec, 
                               CatalogPartition partition, boolean ignoreIfExists)
        throws TableNotExistException, TableNotPartitionedException, PartitionSpecInvalidException,
               PartitionAlreadyExistsException, CatalogException;
    
    /**
     * Drops an existing partition
     * @param tablePath Path identifying the table
     * @param partitionSpec Partition specification
     * @param ignoreIfNotExists Whether to ignore if partition doesn't exist
     * @throws PartitionNotExistException if partition doesn't exist and ignoreIfNotExists is false
     * @throws CatalogException if operation fails
     */
    public void dropPartition(ObjectPath tablePath, CatalogPartitionSpec partitionSpec, boolean ignoreIfNotExists)
        throws PartitionNotExistException, CatalogException;
    
    /**
     * Alters an existing partition
     * @param tablePath Path identifying the table
     * @param partitionSpec Partition specification
     * @param newPartition New partition metadata
     * @param ignoreIfNotExists Whether to ignore if partition doesn't exist
     * @throws PartitionNotExistException if partition doesn't exist and ignoreIfNotExists is false
     * @throws CatalogException if operation fails
     */
    public void alterPartition(ObjectPath tablePath, CatalogPartitionSpec partitionSpec, 
                              CatalogPartition newPartition, boolean ignoreIfNotExists)
        throws PartitionNotExistException, CatalogException;
    
    // Statistics Operations
    
    /**
     * Gets table statistics
     * @param tablePath Path identifying the table
     * @return Table statistics
     * @throws TableNotExistException if table doesn't exist
     * @throws CatalogException if operation fails
     */
    public CatalogTableStatistics getTableStatistics(ObjectPath tablePath)
        throws TableNotExistException, CatalogException;
    
    /**
     * Gets table column statistics
     * @param tablePath Path identifying the table
     * @return Column statistics
     * @throws TableNotExistException if table doesn't exist
     * @throws CatalogException if operation fails
     */
    public CatalogColumnStatistics getTableColumnStatistics(ObjectPath tablePath)
        throws TableNotExistException, CatalogException;
    
    /**
     * Gets partition statistics
     * @param tablePath Path identifying the table
     * @param partitionSpec Partition specification
     * @return Partition statistics
     * @throws PartitionNotExistException if partition doesn't exist
     * @throws CatalogException if operation fails
     */
    public CatalogTableStatistics getPartitionStatistics(ObjectPath tablePath, CatalogPartitionSpec partitionSpec)
        throws PartitionNotExistException, CatalogException;
    
    /**
     * Gets partition column statistics
     * @param tablePath Path identifying the table
     * @param partitionSpec Partition specification
     * @return Partition column statistics
     * @throws PartitionNotExistException if partition doesn't exist
     * @throws CatalogException if operation fails
     */
    public CatalogColumnStatistics getPartitionColumnStatistics(ObjectPath tablePath, CatalogPartitionSpec partitionSpec)
        throws PartitionNotExistException, CatalogException;
    
    // Utility Methods
    
    // Additional Constructors
    
    /**
     * Creates HiveCatalog with explicit HiveConf instance
     * @param catalogName Name of the catalog in Flink
     * @param defaultDatabase Default database name
     * @param hiveConf Hive configuration instance
     * @param hiveVersion Hive version for compatibility
     */
    public HiveCatalog(String catalogName, String defaultDatabase, 
                       HiveConf hiveConf, String hiveVersion);
    
    /**
     * Creates HiveCatalog with HiveConf and embedded metastore control
     * @param catalogName Name of the catalog in Flink
     * @param defaultDatabase Default database name
     * @param hiveConf Hive configuration instance
     * @param hiveVersion Hive version for compatibility
     * @param allowEmbedded Whether to allow embedded metastore
     */
    public HiveCatalog(String catalogName, String defaultDatabase, 
                       HiveConf hiveConf, String hiveVersion, boolean allowEmbedded);
    
    // Configuration and Access Methods
    
    /**
     * Gets the Hive configuration instance
     * @return HiveConf instance used by this catalog
     */
    public HiveConf getHiveConf();
    
    /**
     * Gets the Hive version string
     * @return Hive version (e.g., "3.1.2")
     */
    public String getHiveVersion();
    
    /**
     * Checks if catalog supports managed tables
     * @return True if managed tables are supported
     */
    public boolean supportsManagedTable();
    
    /**
     * Gets factory instance for table factory integration
     * @return Optional Factory instance
     */
    public Optional<Factory> getFactory();
    
    /**
     * Gets table factory for legacy integration
     * @return Optional TableFactory instance
     */
    public Optional<TableFactory> getTableFactory();
    
    /**
     * Gets function definition factory
     * @return Optional FunctionDefinitionFactory instance
     */
    public Optional<FunctionDefinitionFactory> getFunctionDefinitionFactory();
    
    // Static Utility Methods
    
    /**
     * Creates HiveConf from configuration directories
     * @param hiveConfDir Path to Hive configuration directory
     * @param hadoopConfDir Path to Hadoop configuration directory
     * @return Configured HiveConf instance
     */
    public static HiveConf createHiveConf(String hiveConfDir, String hadoopConfDir);
    
    /**
     * Extracts field names from Hive field schema list
     * @param fieldSchemas List of Hive field schemas
     * @return List of field names
     */
    public static List<String> getFieldNames(List<FieldSchema> fieldSchemas);
    
    /**
     * Determines if a table is managed by Hive based on its properties
     * @param properties Table properties map
     * @return True if table is a Hive table, false otherwise
     */
    public static boolean isHiveTable(Map<String, String> properties);
    
    /**
     * Determines if a table is managed by Hive based on table instance
     * @param table CatalogBaseTable instance
     * @return True if table is a Hive table, false otherwise
     */
    public static boolean isHiveTable(CatalogBaseTable table);
    
    /**
     * Checks if the metastore is configured for embedded mode
     * @param hiveConf Hive configuration to check
     * @return True if using embedded metastore, false otherwise
     */
    public static boolean isEmbeddedMetastore(HiveConf hiveConf);
    
    // Hive-specific Operations (Internal API)
    
    /**
     * Gets the underlying Hive Table object
     * @param tablePath Path identifying the table
     * @return Hive Table instance
     * @throws TableNotExistException if table doesn't exist
     */
    public Table getHiveTable(ObjectPath tablePath) throws TableNotExistException;
    
    /**
     * Loads data into a table from external location
     * @param loadPath Path to data files
     * @param tablePath Path identifying the target table
     * @param isOverwrite Whether to overwrite existing data
     * @param isSrcLocal Whether source is on local filesystem
     */
    public void loadTable(Path loadPath, ObjectPath tablePath, boolean isOverwrite, boolean isSrcLocal);
    
    /**
     * Loads data into a specific partition from external location
     * @param loadPath Path to data files
     * @param tablePath Path identifying the target table
     * @param partSpec Partition specification
     * @param isOverwrite Whether to overwrite existing data
     * @param isSrcLocal Whether source is on local filesystem
     */
    public void loadPartition(Path loadPath, ObjectPath tablePath, Map<String, String> partSpec, 
                             boolean isOverwrite, boolean isSrcLocal);
}

// Programmatic catalog creation and registration
import org.apache.flink.table.api.EnvironmentSettings;
import org.apache.flink.table.api.TableEnvironment;
import org.apache.flink.table.catalog.hive.HiveCatalog;

// Create table environment
EnvironmentSettings settings = EnvironmentSettings.newInstance().build();
TableEnvironment tableEnv = TableEnvironment.create(settings);

// Create and register Hive catalog
String catalogName = "hive_catalog";
String defaultDatabase = "default";
String hiveConfDir = "/opt/hive/conf"; // Contains hive-site.xml
String hiveVersion = "3.1.2";

HiveCatalog hive = new HiveCatalog(catalogName, defaultDatabase, hiveConfDir, hiveVersion);
tableEnv.registerCatalog(catalogName, hive);

// Set as current catalog
tableEnv.useCatalog(catalogName);

// Use catalog operations
tableEnv.executeSql("SHOW DATABASES").print();
tableEnv.executeSql("SHOW TABLES").print();
tableEnv.executeSql("DESCRIBE hive_table").print();

-- SQL DDL catalog usage
CREATE CATALOG hive_catalog WITH (
    'type' = 'hive',
    'hive-conf-dir' = '/opt/hive/conf',
    'hive-version' = '3.1.2',
    'hadoop-conf-dir' = '/opt/hadoop/conf'
);

-- Switch to Hive catalog
USE CATALOG hive_catalog;
USE default;

-- Catalog operations
SHOW DATABASES;
SHOW TABLES;
DESCRIBE EXTENDED hive_table;
SHOW PARTITIONS hive_partitioned_table;

-- Create database and tables
CREATE DATABASE analytics_db;
USE analytics_db;

CREATE TABLE user_events (
    user_id BIGINT,
    event_type STRING,
    event_time TIMESTAMP,
    partition_date STRING
) PARTITIONED BY (partition_date)
STORED AS PARQUET;

/**
 * Configuration constants for Hive catalog
 */
public class HiveCatalogConfig {
    /** Default separator for column type lists */
    public static final String DEFAULT_LIST_COLUMN_TYPES_SEPARATOR = ":";
    
    /** Property key for table comments */
    public static final String COMMENT = "comment";
    
    /** Property key for partition location */
    public static final String PARTITION_LOCATION = "partition.location";
    
    /** Property key for table location */
    public static final String TABLE_LOCATION = "location";
    
    /** Property key for storage format */
    public static final String STORED_AS = "stored-as";
    
    /** Property key for input format */
    public static final String INPUT_FORMAT = "input-format";
    
    /** Property key for output format */
    public static final String OUTPUT_FORMAT = "output-format";
    
    /** Property key for serialization library */
    public static final String SERDE_LIB = "serde-lib";
}

// Common exceptions thrown by catalog operations
try {
    CatalogBaseTable table = catalog.getTable(new ObjectPath("db", "table"));
} catch (TableNotExistException e) {
    // Handle missing table
} catch (DatabaseNotExistException e) {
    // Handle missing database  
} catch (CatalogException e) {
    // Handle general catalog errors (connectivity, permissions, etc.)
}