Hello,
this is actually the expected / correct behaviour of Alfresco's implementation of search / query. In either configuration of the search subsystem (Lucene or SOLR), the repository is checked every x seconds (default is 5 for Lucene and 15 for SOLR) for new content to index. Only once new content has been indexed will it be searchable by CMIS SQL. There is no need and no possibility to explicitly "commit" a session, i.e. force an index operation.
Regards
Axel