NXQL search on ancestorId does not work with PostgreSQL sequence idType

2015-09-10 15:28:46,032 ERROR [Nuxeo-Work-elasticSearchIndexing-2] [org.nuxeo.ecm.core.work.AbstractWork] Exception during work: ScrollingIndexingWorker(/elasticSearchIndexing:25485201032301974.718629574, Progress(?%, ?/0), null)
org.nuxeo.ecm.core.api.NuxeoException: Invalid query: NXQL: SELECT ecm:uuid FROM Document WHERE ecm:ancestorId = '9'
	at org.nuxeo.ecm.core.storage.sql.jdbc.JDBCMapper.queryAndFetch(JDBCMapper.java:850)
	at sun.reflect.GeneratedMethodAccessor61.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:497)
	at org.nuxeo.ecm.core.storage.sql.jdbc.JDBCMapperConnector.doInvoke(JDBCMapperConnector.java:22)
	at org.nuxeo.ecm.core.storage.sql.jdbc.JDBCMapperConnector.invoke(JDBCMapperConnector.java:55)
	at com.sun.proxy.$Proxy66.queryAndFetch(Unknown Source)
	at org.nuxeo.ecm.core.storage.sql.SoftRefCachingMapper.queryAndFetch(SoftRefCachingMapper.java:92)
	at org.nuxeo.ecm.core.storage.sql.SessionImpl.queryAndFetch(SessionImpl.java:1187)
	at org.nuxeo.ecm.core.storage.sql.ra.ConnectionImpl.queryAndFetch(ConnectionImpl.java:330)
	at org.nuxeo.ecm.core.storage.sql.coremodel.SQLSession.queryAndFetch(SQLSession.java:435)
	at org.nuxeo.ecm.core.api.AbstractSession.queryAndFetch(AbstractSession.java:1203)
	at org.nuxeo.elasticsearch.work.ScrollingIndexingWorker.doWork(ScrollingIndexingWorker.java:75)
	at org.nuxeo.elasticsearch.work.BaseIndexingWorker.work(BaseIndexingWorker.java:46)
	at org.nuxeo.ecm.core.work.AbstractWork.runWorkWithTransaction(AbstractWork.java:340)
	at org.nuxeo.ecm.core.work.AbstractWork.runWorkWithTransactionAndCheckExceptions(AbstractWork.java:301)
	at org.nuxeo.ecm.core.work.AbstractWork.run(AbstractWork.java:272)
	at org.nuxeo.ecm.core.work.WorkHolder.run(WorkHolder.java:52)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
	at java.lang.Thread.run(Thread.java:745)
Caused by: org.postgresql.util.PSQLException: ERROR: function nx_children(character varying) does not exist
  Hint: No function matches the given name and argument types. You might need to add explicit type casts.
  Position: 380
	at org.postgresql.core.v3.QueryExecutorImpl.receiveErrorResponse(QueryExecutorImpl.java:2157)
	at org.postgresql.core.v3.QueryExecutorImpl.processResults(QueryExecutorImpl.java:1886)
	at org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:255)
	at org.postgresql.jdbc2.AbstractJdbc2Statement.execute(AbstractJdbc2Statement.java:555)
	at org.postgresql.jdbc2.AbstractJdbc2Statement.executeWithFlags(AbstractJdbc2Statement.java:417)
	at org.postgresql.jdbc2.AbstractJdbc2Statement.executeQuery(AbstractJdbc2Statement.java:302)
	at org.tranql.connector.jdbc.PreparedStatementHandle.executeQuery(PreparedStatementHandle.java:52)
	at org.nuxeo.ecm.core.storage.sql.jdbc.ResultSetQueryResult.<init>(ResultSetQueryResult.java:69)
	at org.nuxeo.ecm.core.storage.sql.jdbc.JDBCMapper.queryAndFetch(JDBCMapper.java:848)
	... 20 more