sql语句优化

ORACLE中用到如下语句：
select A,B,C from tableName where
TO_CHAR(A,'yyyy-MM-dd') like '2009-11-09' and B = '600' and A = (select max(A) from tableName where B = '600')
or TO_CHAR(A,'yyyy-MM-dd') like '2009-11-09' and B = '603' and A = (select max(A) from tableName where B = '603')
or TO_CHAR(A,'yyyy-MM-dd') like '2009-11-09' and B = '606' and A = (select max(A) from tableName where B = '606')
or TO_CHAR(A,'yyyy-MM-dd') like '2009-11-09' and B = '609' and A = (select max(A) from tableName where B = '609')
or TO_CHAR(A,'yyyy-MM-dd') like '2009-11-09' and B = '611' and A = (select max(A) from tableName where B = '611')

上述代码中，重复部分比较多，能否简化？？

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SQL code:
select t.* from tableName t where b in ('600','603','606','609','611') and a = (select max(a) from tableName where b in ('600','603','606','609','611') and b = t.b)

select t.* from tableName t where b in ('600','603','606','609','611') and not exists (select 1 from tableName where b in ('600','603','606','609','611') and b = t.b and a > t.a)

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TO_CHAR(A,'yyyy-MM-dd') ='2009-11-09'

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表名是tableName

A      &