SQL select doesn't work

Hello!

I use xwiki with postgresql, xwiki uses hibernate. I have exception on
select, that successful executed in psql:

select distinct xwikidocum0_.XWD_WEB as col_0_0_,
xwikidocum0_.XWD_NAME as col_1_0_, xwikidocum0_.XWD_DATE as col_2_0_
from xwikidoc xwikidocum0_ where (xwikidocum0_.XWD_HIDDEN<>true or
xwikidocum0_.XWD_HIDDEN is null) and 1=1 and
xwikidocum0_.XWD_AUTHOR='XWiki.leonidv' order by xwikidocum0_.XWD_DATE
desc

Exception:
org.postgresql.util.PSQLException: ERROR: could not find hash function
for hash operator 2060
at
org.postgresql.core.v3.QueryExecutorImpl.receiveErrorResponse(QueryExecutorImpl.java:
2102)
at
org.postgresql.core.v3.QueryExecutorImpl.processResults(QueryExecutorImpl.java:
1835)
at
org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:
257)
at
org.postgresql.jdbc2.AbstractJdbc2Statement.execute(AbstractJdbc2Statement.java:
500)
at
org.postgresql.jdbc2.AbstractJdbc2Statement.executeWithFlags(AbstractJdbc2Statement.java:
388)
at
org.postgresql.jdbc2.AbstractJdbc2Statement.executeQuery(AbstractJdbc2Statement.java:
273)
at
org.apache.commons.dbcp.DelegatingPreparedStatement.executeQuery(DelegatingPreparedStatement.java:
96)
at
org.apache.commons.dbcp.DelegatingPreparedStatement.executeQuery(DelegatingPreparedStatement.java:
96)
at
org.apache.commons.dbcp.DelegatingPreparedStatement.executeQuery(DelegatingPreparedStatement.java:
96)
at
org.hibernate.jdbc.AbstractBatcher.getResultSet(AbstractBatcher.java:
186)