Exceptions during data to Oracle (maybe during search index building)

I'm installing new instance of Confluence. I'm migrating data from previous instance which used HSQL database. The both instances are in verson 2.1.5a. Now, I will use Oracle 10g database. Installation procedure is as follows:

1) Extract Confluence Standalone.
2) Copy Oracle JDBC driver 10.2.0.1 to common/lib directory.
3) Set up confluence.home in file conluence-init.properties appropriatelly.
4) Start confluence via ./startup.sh; JAVA_HOME points to JDK 1.5.0_04-b05.
5) Insert licence key on first page of installer, select Oracle10g as external DB.
6) Select connection directly via JDBC driver and set up connection parameters appropriatelly.
7) Select installation with restoring data from backup.

Things go OK while restoring is in progress. When progress bar reach 100%, many of the same exceptions are starting to be written into catalina.out:

java.sql.SQLException: Listener refused the connection with the following error:
ORA-12519, TNS:no appropriate service handler found
The Connection descriptor used by the client was:
localhost:1521:PDB

at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:112)
at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:261)
at oracle.jdbc.driver.T4CConnection.logon(T4CConnection.java:387)
at oracle.jdbc.driver.PhysicalConnection.<init>(PhysicalConnection.java:414)
at oracle.jdbc.driver.T4CConnection.<init>(T4CConnection.java:165)
at oracle.jdbc.driver.T4CDriverExtension.getConnection(T4CDriverExtension.java:35)
at oracle.jdbc.driver.OracleDriver.connect(OracleDriver.java:801)
at com.mchange.v2.c3p0.DriverManagerDataSource.getConnection(DriverManagerDataSource.java:68)
at com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:87)
at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool$1.acquireResource(C3P0PooledConnectionPool.java:83)
at com.mchange.v2.resourcepool.BasicResourcePool.assimilateResource(BasicResourcePool.java:884)
at com.mchange.v2.resourcepool.BasicResourcePool.acquireUntil(BasicResourcePool.java:601)
at com.mchange.v2.resourcepool.BasicResourcePool.access$400(BasicResourcePool.java:31)
at com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask.run(BasicResourcePool.java:1079)
at com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:354)

Data seems to be loaded into new instance of Confluence correctly. The same exceptions repeat while rebuilding search index. I snipped some another exception while index rebuilding; see attached log for details.