DSE Cassandra decimal type

I generated solrschema with dsetool on a table name seriesdata (its key is composed by seriesmetadata_id, initialtime; two decimal field). These fields are defined as DecimalStrField but they are numeric valued (I have to execute range selection). I tried to change schema defining these fields as: but I receive this error: >[cassandra@bigdatalin-03 ~]$ dsetool reload_core timeseriesks.seriesdata schema=schema_data.xml solrconfig=solr_config_data.xml reindex=true -l cassandra -p cassandra org.apache.solr.client.solrj.impl.HttpSolrServer$RemoteSolrException: com.datastax.bdp.search.solr.CassandraIndexSchema$ValidationException: Mismatch between Solr key field [seriesmetadata_id] with type {TrieLongField{class=org.apache.solr.schema.TrieLongField,analyzer=org.apache.solr.schema.FieldType$DefaultAnalyzer,args={class=org.apache.solr.schema.TrieLongField}}] and Cassandra key alias [seriesmetadata_id] with type [decimal] at org.apache.solr.client.solrj.impl.HttpSolrServer.executeMethod(HttpSolrServer.java:665) at org.apache.solr.client.solrj.impl.HttpSolrServer.request(HttpSolrServer.java:303) at org.apache.solr.client.solrj.impl.HttpSolrServer.request(HttpSolrServer.java:294) at com.datastax.bdp.tools.SearchDseToolCommands.createOrReloadCore(SearchDseToolCommands.java:559) at com.datastax.bdp.tools.SearchDseToolCommands.access$200(SearchDseToolCommands.java:59) at com.datastax.bdp.tools.SearchDseToolCommands$ReloadCore.execute(SearchDseToolCommands.java:209) at com.datastax.bdp.tools.DseTool.run(DseTool.java:126) at com.datastax.bdp.tools.DseTool.run(DseTool.java:51) at com.datastax.bdp.tools.DseTool.main(DseTool.java:186) Why? Thanks a lot!