include the JDBC fetch size in the database info log

Author: gavinking

hibernate-agroal/src/main/java/org/hibernate/agroal/internal/AgroalConnectionProvider.java

@@ -181,10 +181,22 @@ public DatabaseConnectionInfo getDatabaseConnectionInfo(Dialect dialect) {
 						? ConnectionProviderInitiator.toIsolationNiceName( acfc.jdbcTransactionIsolation().level() )
 						: null,
 				acpc.minSize(),
-				acpc.maxSize()
+				acpc.maxSize(),
+				getFetchSize( agroalDataSource )
 		);
 	}
 
+	private static Integer getFetchSize(DataSource dataSource) {
+		try ( var conn = dataSource.getConnection() ) {
+			try ( var statement = conn.createStatement() ) {
+				return statement.getFetchSize();
+			}
+		}
+		catch ( SQLException ignored ) {
+			return null;
+		}
+	}
+
 	private String extractDriverNameFromMetadata() {
 		if (isMetadataAccessAllowed) {
 			try ( Connection conn = getConnection() ) {

hibernate-c3p0/src/main/java/org/hibernate/c3p0/internal/C3P0ConnectionProvider.java

@@ -165,10 +165,22 @@ public void configure(Map<String, Object> properties) {
 				requireNonNullElse( getInteger( C3P0_STYLE_MIN_POOL_SIZE.substring( 5 ), poolSettings ),
 						DEFAULT_MIN_POOL_SIZE ),
 				requireNonNullElse( getInteger( C3P0_STYLE_MAX_POOL_SIZE.substring( 5 ), poolSettings ),
-						DEFAULT_MAX_POOL_SIZE )
+						DEFAULT_MAX_POOL_SIZE ),
+				getFetchSize( dataSource )
 		);
 	}
 
+	private static Integer getFetchSize(DataSource dataSource) {
+		try ( var conn = dataSource.getConnection() ) {
+			try ( var statement = conn.createStatement() ) {
+				return statement.getFetchSize();
+			}
+		}
+		catch ( SQLException ignored ) {
+			return null;
+		}
+	}
+
 	private DataSource createDataSource(String jdbcUrl, Properties connectionProps, Map<String, Object> poolProperties) {
 		try {
 			return pooledDataSource( unpooledDataSource( jdbcUrl, connectionProps ), poolProperties );

hibernate-core/src/main/java/org/hibernate/engine/jdbc/connections/internal/DatabaseConnectionInfoImpl.java

@@ -6,6 +6,7 @@
 
 import java.util.Map;
 
+import org.checkerframework.checker.nullness.qual.Nullable;
 import org.hibernate.cfg.JdbcSettings;
 import org.hibernate.dialect.DatabaseVersion;
 import org.hibernate.dialect.Dialect;
@@ -37,6 +38,7 @@ public class DatabaseConnectionInfoImpl implements DatabaseConnectionInfo {
 	protected final String isolationLevel;
 	protected final Integer poolMinSize;
 	protected final Integer poolMaxSize;
+	private final Integer fetchSize;
 
 	public DatabaseConnectionInfoImpl(
 			Class<? extends ConnectionProvider> connectionProviderClass,
@@ -46,7 +48,8 @@ public DatabaseConnectionInfoImpl(
 			String autoCommitMode,
 			String isolationLevel,
 			Integer poolMinSize,
-			Integer poolMaxSize) {
+			Integer poolMaxSize,
+			Integer fetchSize) {
 		this.connectionProviderClass = connectionProviderClass;
 		this.jdbcUrl = nullIfEmpty( jdbcUrl );
 		this.jdbcDriver = nullIfEmpty( jdbcDriver );
@@ -55,6 +58,7 @@ public DatabaseConnectionInfoImpl(
 		this.isolationLevel = nullIfEmpty( isolationLevel );
 		this.poolMinSize = poolMinSize;
 		this.poolMaxSize = poolMaxSize;
+		this.fetchSize = fetchSize;
 	}
 
 	public DatabaseConnectionInfoImpl(Map<String, Object> settings, Dialect dialect) {
@@ -67,12 +71,13 @@ public DatabaseConnectionInfoImpl(Map<String, Object> settings, Dialect dialect)
 				determineIsolationLevel( settings ),
 				// No setting for min. pool size
 				null,
-				determinePoolMaxSize( settings )
+				determinePoolMaxSize( settings ),
+				null
 		);
 	}
 
 	public DatabaseConnectionInfoImpl(Dialect dialect) {
-		this( null, null, null, dialect.getVersion(), null, null, null, null );
+		this( null, null, null, dialect.getVersion(), null, null, null, null, null );
 	}
 
 	@Override
@@ -110,16 +115,34 @@ public Integer getPoolMaxSize() {
 		return poolMaxSize;
 	}
 
+	@Override
+	public @Nullable Integer getJdbcFetchSize() {
+		return fetchSize;
+	}
+
 	@Override
 	public String toInfoString() {
-		return "\tDatabase JDBC URL [" + handleEmpty( jdbcUrl ) + ']' +
-				"\n\tDatabase driver: " + handleEmpty( jdbcDriver ) +
-				"\n\tDatabase version: " + handleEmpty( dialectVersion ) +
-				"\n\tAutocommit mode: " + handleEmpty( autoCommitMode ) +
-				"\n\tIsolation level: " + handleEmpty( isolationLevel ) +
-				"\n\tPool: " + handleEmpty( connectionProviderClass ) +
-				"\n\tMinimum pool size: " + handleEmpty( poolMinSize ) +
-				"\n\tMaximum pool size: " + handleEmpty( poolMaxSize );
+		return """
+				\tDatabase JDBC URL [%s]
+				\tDatabase driver: %s
+				\tDatabase version: %s
+				\tAutocommit mode: %s
+				\tIsolation level: %s
+				\tPool: %s
+				\tMinimum pool size: %s
+				\tMaximum pool size: %s
+				\tJDBC fetch size: %s"""
+				.formatted(
+						handleEmpty( jdbcUrl ),
+						handleEmpty( jdbcDriver ),
+						handleEmpty( dialectVersion ),
+						handleEmpty( autoCommitMode ),
+						handleEmpty( isolationLevel ),
+						handleEmpty( connectionProviderClass ),
+						handleEmpty( poolMinSize ),
+						handleEmpty( poolMaxSize ),
+						handleEmpty( fetchSize )
+				);
 	}
 
 	private static String handleEmpty(String value) {
@@ -131,6 +154,10 @@ private static String handleEmpty(DatabaseVersion dialectVersion) {
 	}
 
 	private static String handleEmpty(Integer value) {
+		return value != null ? ( value == 0 ? "none" : value.toString() ) : DEFAULT;
+	}
+
+	private static String handleFetchSize(Integer value) {
 		return value != null ? value.toString() : DEFAULT;
 	}
 

hibernate-core/src/main/java/org/hibernate/engine/jdbc/connections/internal/DatasourceConnectionProviderImpl.java

@@ -160,16 +160,21 @@ public DatabaseConnectionInfo getDatabaseConnectionInfo(Dialect dialect, Extract
 		final String url;
 		final String driver;
 		final String isolationLevel;
+		final Integer fetchSize;
 		if ( metaData != null ) {
 			url = metaData.getUrl();
 			driver = metaData.getDriver();
-			isolationLevel = toIsolationNiceName( metaData.getTransactionIsolation() )
+			isolationLevel =
+					toIsolationNiceName( metaData.getTransactionIsolation() )
 							+ " [default " + toIsolationNiceName( metaData.getDefaultTransactionIsolation() ) + "]";
+			final int defaultFetchSize = metaData.getDefaultFetchSize();
+			fetchSize = defaultFetchSize == -1 ? null : defaultFetchSize;
 		}
 		else {
 			url = null;
 			driver = null;
 			isolationLevel = null;
+			fetchSize = null;
 		}
 
 		return new DatabaseConnectionInfoImpl(
@@ -180,7 +185,8 @@ public DatabaseConnectionInfo getDatabaseConnectionInfo(Dialect dialect, Extract
 				null,
 				isolationLevel,
 				null,
-				null
+				null,
+				fetchSize
 		) {
 			@Override
 			public String toInfoString() {

hibernate-core/src/main/java/org/hibernate/engine/jdbc/connections/internal/DriverManagerConnectionProviderImpl.java

@@ -150,7 +150,8 @@ private static ConnectionCreator buildCreator(
 				Boolean.toString( autoCommit ),
 				isolation != null ? toIsolationNiceName( isolation ) : null,
 				getInt( MIN_SIZE, configurationValues, 1 ),
-				getInt( AvailableSettings.POOL_SIZE, configurationValues, 20 )
+				getInt( AvailableSettings.POOL_SIZE, configurationValues, 20 ),
+				null
 		);
 
 		return factory.create(
@@ -292,7 +293,8 @@ public DatabaseConnectionInfo getDatabaseConnectionInfo(Dialect dialect) {
 				dbInfo.getAutoCommitMode(),
 				dbInfo.getIsolationLevel(),
 				dbInfo.getPoolMinSize(),
-				dbInfo.getPoolMaxSize()
+				dbInfo.getPoolMaxSize(),
+				dbInfo.getJdbcFetchSize()
 		);
 	}
 

hibernate-core/src/main/java/org/hibernate/engine/jdbc/connections/spi/DataSourceBasedMultiTenantConnectionProviderImpl.java

@@ -125,6 +125,7 @@ public DatabaseConnectionInfo getDatabaseConnectionInfo(Dialect dialect) {
 				null,
 				null,
 				null,
+				null,
 				null
 		) {
 			@Override

hibernate-core/src/main/java/org/hibernate/engine/jdbc/connections/spi/DatabaseConnectionInfo.java

@@ -61,6 +61,12 @@ public interface DatabaseConnectionInfo {
 	@Nullable
 	Integer getPoolMaxSize();
 
+	/**
+	 * The default JDBC fetch size.
+	 */
+	@Nullable
+	Integer getJdbcFetchSize();
+
 	/**
 	 * Collects the information available here as a single String with the intent of using it in logging.
 	 */

hibernate-core/src/main/java/org/hibernate/engine/jdbc/env/spi/ExtractedDatabaseMetaData.java

@@ -151,7 +151,7 @@ public interface ExtractedDatabaseMetaData {
 	int getDefaultTransactionIsolation();
 
 	/**
-	 * Retrieve the default JDBC {@link java.sql.Statement#getFetchSize fetch size}.
+	 * Retrieve the default JDBC {@linkplain java.sql.Statement#getFetchSize fetch size}.
 	 */
 	int getDefaultFetchSize();
 

hibernate-hikaricp/src/main/java/org/hibernate/hikaricp/internal/HikariCPConnectionProvider.java

@@ -107,10 +107,22 @@ public DatabaseConnectionInfo getDatabaseConnectionInfo(Dialect dialect) {
 				Boolean.toString( hikariConfig.isAutoCommit() ),
 				hikariConfig.getTransactionIsolation(),
 				hikariConfig.getMinimumIdle(),
-				hikariConfig.getMaximumPoolSize()
+				hikariConfig.getMaximumPoolSize(),
+				getFetchSize( hikariDataSource )
 		);
 	}
 
+	private static Integer getFetchSize(DataSource dataSource) {
+		try ( var conn = dataSource.getConnection() ) {
+			try ( var statement = conn.createStatement() ) {
+				return statement.getFetchSize();
+			}
+		}
+		catch ( SQLException ignored ) {
+			return null;
+		}
+	}
+
 	private String extractDriverNameFromMetadata() {
 		if ( isMetadataAccessAllowed ) {
 			try ( Connection conn = getConnection() ) {