Support DB2 functions in H2 database while unit testing

We have a DB2 database in production, and we are setting up a H2 in-memory database for tests. I understand that not all DB2 functions are supported in H2 even when we configured it in DB2 mode. How do we unit test SQLs that contains database specific functions but are not yet supported in H2?

If we start writing H2 specific DB services then we will end writing different layer of functional code.

Function not supported

VARCHAR_FORMAT

H2 configuration

jdbc:h2:mem:test;MODE=DB2

H2 version

1.4.188

Java stacktrace

Caused by: org.h2.jdbc.JdbcSQLException: Function "VARCHAR_FORMAT" not found; SQL statement:
select S.SCHEDULE_ID scheduleId, VARCHAR_FORMAT(S.START_DATE, 'DD-Mon-YYYY') startDate
from ScheduleSubscription S WITH UR  [90022-182]
    at org.h2.message.DbException.getJdbcSQLException(DbException.java:345) ~[h2-1.4.182.jar:1.4.182]
    at org.h2.message.DbException.get(DbException.java:179) ~[h2-1.4.182.jar:1.4.182]
    at org.h2.message.DbException.get(DbException.java:155) ~[h2-1.4.182.jar:1.4.182]
    at org.h2.command.Parser.readJavaFunction(Parser.java:2333) ~[h2-1.4.182.jar:1.4.182]
    at org.h2.command.Parser.readFunction(Parser.java:2385) ~[h2-1.4.182.jar:1.4.182]
    at org.h2.command.Parser.readTerm(Parser.java:2719) ~[h2-1.4.182.jar:1.4.182]
    at org.h2.command.Parser.readFactor(Parser.java:2251) ~[h2-1.4.182.jar:1.4.182]
    at org.h2.command.Parser.readSum(Parser.java:2238) ~[h2-1.4.182.jar:1.4.182]
    at org.h2.command.Parser.readConcat(Parser.java:2208) ~[h2-1.4.182.jar:1.4.182]
    at org.h2.command.Parser.readCondition(Parser.java:2058) ~[h2-1.4.182.jar:1.4.182]
    at org.h2.command.Parser.readAnd(Parser.java:2030) ~[h2-1.4.182.jar:1.4.182]
    at org.h2.command.Parser.readExpression(Parser.java:2022) ~[h2-1.4.182.jar:1.4.182]
    at org.h2.command.Parser.parseSelectSimpleSelectPart(Parser.java:1934) ~[h2-1.4.182.jar:1.4.182]
    at org.h2.command.Parser.parseSelectSimple(Parser.java:1966) ~[h2-1.4.182.jar:1.4.182]
    at org.h2.command.Parser.parseSelectSub(Parser.java:1860) ~[h2-1.4.182.jar:1.4.182]
    at org.h2.command.Parser.parseSelectUnion(Parser.java:1681) ~[h2-1.4.182.jar:1.4.182]
    at org.h2.command.Parser.parseSelect(Parser.java:1669) ~[h2-1.4.182.jar:1.4.182]
    at org.h2.command.Parser.parsePrepared(Parser.java:433) ~[h2-1.4.182.jar:1.4.182]
    at org.h2.command.Parser.parse(Parser.java:305) ~[h2-1.4.182.jar:1.4.182]
    at org.h2.command.Parser.parse(Parser.java:277) ~[h2-1.4.182.jar:1.4.182]
    at org.h2.command.Parser.prepareCommand(Parser.java:242) ~[h2-1.4.182.jar:1.4.182]
    at org.h2.engine.Session.prepareLocal(Session.java:446) ~[h2-1.4.182.jar:1.4.182]
    at org.h2.engine.Session.prepareCommand(Session.java:388) ~[h2-1.4.182.jar:1.4.182]
    at org.h2.jdbc.JdbcConnection.prepareCommand(JdbcConnection.java:1190) ~[h2-1.4.182.jar:1.4.182]
    at org.h2.jdbc.JdbcPreparedStatement.<init>(JdbcPreparedStatement.java:72) ~[h2-1.4.182.jar:1.4.182]
    at org.h2.jdbc.JdbcConnection.prepareStatement(JdbcConnection.java:666) ~[h2-1.4.182.jar:1.4.182]
    at org.apache.commons.dbcp.DelegatingConnection.prepareStatement(DelegatingConnection.java:295) ~[commons-dbcp-1.4.jar:1.4]
    at org.apache.commons.dbcp.PoolingDataSource$PoolGuardConnectionWrapper.prepareStatement(PoolingDataSource.java:318) ~[commons-dbcp-1.4.jar:1.4]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.6.0_35]
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) ~[na:1.6.0_35]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) ~[na:1.6.0_35]
    at java.lang.reflect.Method.invoke(Method.java:597) ~[na:1.6.0_35]
    at org.apache.ibatis.logging.jdbc.ConnectionLogger.invoke(ConnectionLogger.java:54) ~[mybatis-3.2.8.jar:3.2.8]
    at $Proxy35.prepareStatement(Unknown Source) ~[na:na]
    at org.apache.ibatis.executor.statement.PreparedStatementHandler.instantiateStatement(PreparedStatementHandler.java:73) ~[mybatis-3.2.8.jar:3.2.8]
    at org.apache.ibatis.executor.statement.BaseStatementHandler.prepare(BaseStatementHandler.java:85) ~[mybatis-3.2.8.jar:3.2.8]
    at org.apache.ibatis.executor.statement.RoutingStatementHandler.prepare(RoutingStatementHandler.java:57) ~[mybatis-3.2.8.jar:3.2.8]
    at org.apache.ibatis.executor.SimpleExecutor.prepareStatement(SimpleExecutor.java:73) ~[mybatis-3.2.8.jar:3.2.8]
    at org.apache.ibatis.executor.SimpleExecutor.doQuery(SimpleExecutor.java:59) ~[mybatis-3.2.8.jar:3.2.8]
    at org.apache.ibatis.executor.BaseExecutor.queryFromDatabase(BaseExecutor.java:267) ~[mybatis-3.2.8.jar:3.2.8]
    at org.apache.ibatis.executor.BaseExecutor.query(BaseExecutor.java:137) ~[mybatis-3.2.8.jar:3.2.8]
    at org.apache.ibatis.executor.CachingExecutor.query(CachingExecutor.java:96) ~[mybatis-3.2.8.jar:3.2.8]
    at org.apache.ibatis.executor.CachingExecutor.query(CachingExecutor.java:77) ~[mybatis-3.2.8.jar:3.2.8]
    at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:108) ~[mybatis-3.2.8.jar:3.2.8]
    at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:102) ~[mybatis-3.2.8.jar:3.2.8]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.6.0_35]
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) ~[na:1.6.0_35]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) ~[na:1.6.0_35]
    at java.lang.reflect.Method.invoke(Method.java:597) ~[na:1.6.0_35]
    at org.mybatis.spring.SqlSessionTemplate$SqlSessionInterceptor.invoke(SqlSessionTemplate.java:358) ~[mybatis-spring-1.2.2.jar:1.2.2]
    ... 47 common frames omitted