Hello,
My topic is related to this task https://jira.mariadb.org/browse/CONJ-440.

When I'm trying to store BLOB file, which size is 1GB and using useServerPrepStmts=true, then I get the following exception:
_java.lang.OutOfMemoryError: Java heap space
at java.util.Arrays.copyOf(Unknown Source)
at java.io.ByteArrayOutputStream.toByteArray(Unknown Source)
at org.mariadb.jdbc.internal.packet.dao.parameters.StreamParameter.toString(StreamParameter.java:172)
at org.mariadb.jdbc.internal.protocol.AbstractQueryProtocol.throwErrorWithQuery(AbstractQueryProtocol.java:976)
at org.mariadb.jdbc.internal.protocol.AbstractQueryProtocol.executePreparedQuery(AbstractQueryProtocol.java:620)
at org.mariadb.jdbc.MariaDbServerPreparedStatement.executeInternal(MariaDbServerPreparedStatement.java:401)
at org.mariadb.jdbc.MariaDbServerPreparedStatement.execute(MariaDbServerPreparedStatement.java:362)
at org.mariadb.jdbc.MariaDbServerPreparedStatement.executeUpdate(MariaDbServerPreparedStatement.java:351)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at oracle.ucp.jdbc.proxy.StatementProxyFactory.invoke(StatementProxyFactory.java:272)
at oracle.ucp.jdbc.proxy.PreparedStatementProxyFactory.invoke(PreparedStatementProxyFactory.java:138)
at com.sun.proxy.$Proxy11.executeUpdate(Unknown Source)
at TransferDataTableAccess.storeBinaryData(TransferDataTableAccess.java:596)
at TransferDataTableAccessTest.testTransferDataTableAccess(TransferDataTableAccessTest.java:155)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:47)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:44)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:27)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:271)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:70)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:50)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63)_

The similar is happening when useServerPrepStmts=false.
_java.lang.OutOfMemoryError: Requested array size exceeds VM limit
at java.nio.HeapByteBuffer.<init>(Unknown Source)
at java.nio.ByteBuffer.allocate(Unknown Source)
at org.mariadb.jdbc.internal.stream.PacketOutputStream.increase(PacketOutputStream.java:111)
at org.mariadb.jdbc.internal.stream.PacketOutputStream.assureBufferCapacity(PacketOutputStream.java:598)
at org.mariadb.jdbc.internal.stream.PacketOutputStream.write(PacketOutputStream.java:376)
at org.mariadb.jdbc.internal.packet.dao.parameters.ParameterWriter.writeBytesEscaped(ParameterWriter.java:78)
at org.mariadb.jdbc.internal.packet.dao.parameters.ParameterWriter.write(ParameterWriter.java:142)
at org.mariadb.jdbc.internal.packet.dao.parameters.StreamParameter.writeTo(StreamParameter.java:94)
at org.mariadb.jdbc.internal.packet.ComExecute.sendSubCmd(ComExecute.java:89)
at org.mariadb.jdbc.internal.protocol.AbstractQueryProtocol.executeQuery(AbstractQueryProtocol.java:200)
at org.mariadb.jdbc.MariaDbClientPreparedStatement.executeInternal(MariaDbClientPreparedStatement.java:224)
at org.mariadb.jdbc.MariaDbClientPreparedStatement.executeUpdate(MariaDbClientPreparedStatement.java:197)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at oracle.ucp.jdbc.proxy.StatementProxyFactory.invoke(StatementProxyFactory.java:272)
at oracle.ucp.jdbc.proxy.PreparedStatementProxyFactory.invoke(PreparedStatementProxyFactory.java:138)
at com.sun.proxy.$Proxy11.executeUpdate(Unknown Source)
at TransferDataTableAccess.storeBinaryData(TransferDataTableAccess.java:596)
at TransferDataTableAccessTest.testTransferDataTableAccess(TransferDataTableAccessTest.java:155)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:47)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:44)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:27)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:271)_

My.ini is the following:
sql_mode="STRICT_TRANS_TABLES,NO_ENGINE_SUBSTITUTION"
default_storage_engine=innodb
innodb_buffer_pool_size=4G
innodb_log_file_size=4G
innodb_file_format=barracuda
innodb_strict_mode=on
innodb_large_prefix=on
innodb_file_per_table=1
character-set-server=utf8
max_allowed_packet=1G
innodb_flush_method=ALL_O_DIRECT

I have also tried to put -Xmx6144m -ea -Djava.awt.headless=true for execution.
In the new version of MariaDB connector (1.5.9) the speed of storing of BLOB objects has been decreased comparing to the version 1.5.7 (approximately 2x slower).