diff --git a/src/main/resources/schema.cql b/src/main/resources/schema.cql
index 9bce2c15..af74b566 100644
--- a/src/main/resources/schema.cql
+++ b/src/main/resources/schema.cql
@@ -3,4 +3,5 @@ USE __KEYSPACE__;
 CREATE TABLE IF NOT EXISTS __KEYSPACE__.meta (sha1 ascii, repo text, commit ascii, path text, PRIMARY KEY (sha1, repo, commit, path));
 CREATE TABLE IF NOT EXISTS __KEYSPACE__.hashtables_file (sha1 text, hashtable tinyint, value blob, PRIMARY KEY (hashtable, value, sha1));
 CREATE TABLE IF NOT EXISTS __KEYSPACE__.hashtables_func (sha1 text, hashtable tinyint, value blob, PRIMARY KEY (hashtable, value, sha1));
-CREATE TABLE IF NOT EXISTS __KEYSPACE__.docfreq (id text, docs int, df map<text, int>, PRIMARY KEY (id));
+CREATE TABLE IF NOT EXISTS __KEYSPACE__.features_docs (id text, docs int, PRIMARY KEY (id));
+CREATE TABLE IF NOT EXISTS __KEYSPACE__.features_freq (id text, feature text, weight int, PRIMARY KEY (id, feature));
diff --git a/src/main/scala/tech/sourced/gemini/Database.scala b/src/main/scala/tech/sourced/gemini/Database.scala
index 01ba0984..dcb3f65a 100644
--- a/src/main/scala/tech/sourced/gemini/Database.scala
+++ b/src/main/scala/tech/sourced/gemini/Database.scala
@@ -7,22 +7,31 @@ import scala.collection.JavaConverters._
 
 case class MetaCols(sha: String, repo: String, commit: String, path: String)
 case class HashtablesCols(sha: String, hashtable: String, value: String)
-case class DocFreqCols(id: String, docs: String, df: String)
+case class FeaturesDocsCols(id: String, docs: String)
+case class FeaturesFreqCols(id: String, feature: String, weight: String)
 
 /**
   * Tables is static typed definition of DB schema
   *
   * @param meta name of meta table
-  * @param hashtables name of hashtables table
-  * @param metaCols
-  * @param hashtablesCols
+  * @param hashtables prefix of hashtables table
+  * @param featuresDocs name of features documents table
+  * @param featuresFreq name of features frequencies table
+  * @param metaCols columns of meta table
+  * @param hashtablesCols columns of hashtables table
+  * @param featuresDocsCols columns of features documents table
+  * @param featuresFreqCols columns of features frequencies table
   */
 case class Tables(meta: String,
                   hashtables: String,
-                  docFreq: String,
+                  featuresDocs: String,
+                  featuresFreq: String,
                   metaCols: MetaCols,
                   hashtablesCols: HashtablesCols,
-                  docFreqCols: DocFreqCols)
+                  featuresDocsCols: FeaturesDocsCols,
+                  featuresFreqCols: FeaturesFreqCols) {
+  def hashtables(mode: String): String = s"${hashtables}_$mode"
+}
 
 /**
   * Database object contains common queries to DB
diff --git a/src/main/scala/tech/sourced/gemini/FileQuery.scala b/src/main/scala/tech/sourced/gemini/FileQuery.scala
index 41148d71..16400240 100644
--- a/src/main/scala/tech/sourced/gemini/FileQuery.scala
+++ b/src/main/scala/tech/sourced/gemini/FileQuery.scala
@@ -135,7 +135,6 @@ class FileQuery(
       case Gemini.funcSimilarityMode => FeaturesHash.funcParams
     }
 
-    val hashtablesTable = s"${tables.hashtables}_${mode}"
     val cols = tables.hashtablesCols
     val wmh = hashFile(featuresList, docFreq, sampleSize)
 
@@ -143,7 +142,7 @@ class FileQuery(
 
     log.info("Looking for similar items")
     val similar = bands.zipWithIndex.foldLeft(Set[String]()) { case (sim, (band, i)) =>
-      val cql = s"""SELECT ${cols.sha} FROM $keyspace.${hashtablesTable}
+      val cql = s"""SELECT ${cols.sha} FROM $keyspace.${tables.hashtables(mode)}
         WHERE ${cols.hashtable}=$i AND ${cols.value}=0x${MathUtil.bytes2hex(band)}"""
       log.debug(cql)
 
@@ -186,18 +185,26 @@ class FileQuery(
 
   protected def readDocFreqFromDB(): Option[OrderedDocFreq] = {
     log.info(s"Reading docFreq from DB")
-    val cols = tables.docFreqCols
-    val row = conn.execute(s"SELECT * FROM ${tables.docFreq} WHERE ${cols.id} = '${mode}'").one()
-    if (row == null) {
+    val docsCols = tables.featuresDocsCols
+    val freqCols = tables.featuresFreqCols
+    val docsRow = conn.execute(s"SELECT * FROM ${tables.featuresDocs} WHERE ${docsCols.id} = '$mode'").one()
+    if (docsRow == null) {
       log.warn("Document frequency table is empty.")
       None
     } else {
-      val df = row
-        .getMap("df", classOf[java.lang.String], classOf[java.lang.Integer])
+      var tokens = IndexedSeq[String]()
+      val df = conn
+        .execute(s"SELECT * FROM ${tables.featuresFreq} WHERE ${freqCols.id} = '$mode' ORDER BY ${freqCols.feature}")
         .asScala
-        .mapValues(_.toInt)
+        .map { row =>
+          // tokens have to be sorted, df.keys isn't sorted
+          val name = row.getString(freqCols.feature)
+          tokens = tokens :+ name
 
-      Some(OrderedDocFreq(row.getInt(cols.docs), df.keys.toIndexedSeq, df))
+          (name, row.getInt(freqCols.weight))
+        }.toMap
+
+      Some(OrderedDocFreq(docsRow.getInt(docsCols.docs), tokens, df))
     }
   }
 
diff --git a/src/main/scala/tech/sourced/gemini/Gemini.scala b/src/main/scala/tech/sourced/gemini/Gemini.scala
index a04d520a..95b799d1 100644
--- a/src/main/scala/tech/sourced/gemini/Gemini.scala
+++ b/src/main/scala/tech/sourced/gemini/Gemini.scala
@@ -130,13 +130,18 @@ class Gemini(session: SparkSession, log: Slf4jLogger, keyspace: String = Gemini.
   }
 
   def isDBEmpty(session: Session, mode: String): Boolean = {
-    var row = session.execute(s"select count(*) from $keyspace.${tables.docFreq} where id='$mode' limit 1").one()
-    if (row.getLong(0) > 0) {
+    var row = session.execute(s"select * from $keyspace.${tables.featuresDocs} where id='$mode' limit 1").one()
+    if (row != null) {
       return false
     }
 
-    row = session.execute(s"select count(*) from $keyspace.${tables.hashtables}_$mode").one()
-    if (row.getLong(0) > 0) {
+    row = session.execute(s"select * from $keyspace.${tables.featuresFreq} where id='$mode' limit 1").one()
+    if (row != null) {
+      return false
+    }
+
+    row = session.execute(s"select * from $keyspace.${tables.hashtables}_$mode limit 1").one()
+    if (row != null) {
       return false
     }
 
@@ -144,8 +149,9 @@ class Gemini(session: SparkSession, log: Slf4jLogger, keyspace: String = Gemini.
   }
 
   def cleanDB(session: Session, mode: String): Unit = {
-    session.execute(s"delete from $keyspace.${tables.docFreq} where id='$mode'")
-    session.execute(s"truncate table $keyspace.${tables.hashtables}_$mode")
+    session.execute(s"delete from $keyspace.${tables.featuresDocs} where id='$mode'")
+    session.execute(s"delete from $keyspace.${tables.featuresFreq} where id='$mode'")
+    session.execute(s"truncate table $keyspace.${tables.hashtables(mode)}")
   }
 
   def applySchema(session: Session): Unit = {
@@ -198,10 +204,12 @@ object Gemini {
   val tables = Tables(
     "meta",
     "hashtables",
-    "docfreq",
+    "features_docs",
+    "features_freq",
     MetaCols("sha1", "repo", "commit", "path"),
     HashtablesCols("sha1", "hashtable", "value"),
-    DocFreqCols("id", "docs", "df")
+    FeaturesDocsCols("id", "docs"),
+    FeaturesFreqCols("id", "feature", "weight")
   )
 
   val formatter = new ObjectInserter.Formatter
diff --git a/src/main/scala/tech/sourced/gemini/Hash.scala b/src/main/scala/tech/sourced/gemini/Hash.scala
index 71525e8d..175597b0 100644
--- a/src/main/scala/tech/sourced/gemini/Hash.scala
+++ b/src/main/scala/tech/sourced/gemini/Hash.scala
@@ -229,14 +229,21 @@ class Hash(session: SparkSession,
 
   protected def saveDocFreqToDB(docFreq: OrderedDocFreq, keyspace: String, tables: Tables): Unit = {
     log.warn(s"save document frequencies to DB")
-    CassandraConnector(session.sparkContext).withSessionDo { cassandra =>
-      val cols = tables.docFreqCols
-      val javaMap = docFreq.df.asJava
 
+    CassandraConnector(session.sparkContext).withSessionDo { cassandra =>
+      val docsCols = tables.featuresDocsCols
       cassandra.execute(
-        s"INSERT INTO $keyspace.${tables.docFreq} (${cols.id}, ${cols.docs}, ${cols.df}) VALUES (?, ?, ?)",
-        mode, int2Integer(docFreq.docs), javaMap
+        s"INSERT INTO $keyspace.${tables.featuresDocs} (${docsCols.id}, ${docsCols.docs}) VALUES (?, ?)",
+        mode, int2Integer(docFreq.docs)
       )
+
+      val freqCols = tables.featuresFreqCols
+      val prepared = cassandra.prepare(s"INSERT INTO $keyspace.${tables.featuresFreq}" +
+        s"(${freqCols.id}, ${freqCols.feature}, ${freqCols.weight}) VALUES (?, ?, ?)")
+
+      docFreq.df.foreach { case(feature, weight) =>
+        cassandra.execute(prepared.bind(mode, feature, int2Integer(weight)))
+      }
     }
   }
 
@@ -267,7 +274,6 @@ class Hash(session: SparkSession,
       case Gemini.funcSimilarityMode => FeaturesHash.funcParams
     }
 
-    val hashtablesTable = s"${tables.hashtables}_${mode}"
     val cols = tables.hashtablesCols
     rdd
       .flatMap { case RDDHash(doc, wmh) =>
@@ -276,7 +282,7 @@ class Hash(session: SparkSession,
       .toDF(cols.sha, cols.hashtable, cols.value)
       .write
       .mode("append")
-      .cassandraFormat(hashtablesTable, keyspace)
+      .cassandraFormat(tables.hashtables(mode), keyspace)
       .save()
   }
 
diff --git a/src/main/scala/tech/sourced/gemini/Report.scala b/src/main/scala/tech/sourced/gemini/Report.scala
index 0260848e..06af45c3 100644
--- a/src/main/scala/tech/sourced/gemini/Report.scala
+++ b/src/main/scala/tech/sourced/gemini/Report.scala
@@ -63,8 +63,7 @@ class Report(conn: Session, log: Slf4jLogger, keyspace: String, tables: Tables)
     */
   def findConnectedComponents(mode: String): (Map[Int, Set[Int]], Map[Int, List[Int]], Map[String, Int]) = {
     log.info(s"Finding ${mode} connected components")
-    val hashtablesTable = s"${tables.hashtables}_${mode}"
-    val cc = new DBConnectedComponents(log, conn, hashtablesTable, keyspace)
+    val cc = new DBConnectedComponents(log, conn, tables.hashtables(mode), keyspace)
     val (buckets, elementIds) = cc.makeBuckets()
     val elsToBuckets = cc.elementsToBuckets(buckets)
 
diff --git a/src/test/scala/tech/sourced/gemini/BaseDBSpec.scala b/src/test/scala/tech/sourced/gemini/BaseDBSpec.scala
index ce52469b..617e693c 100644
--- a/src/test/scala/tech/sourced/gemini/BaseDBSpec.scala
+++ b/src/test/scala/tech/sourced/gemini/BaseDBSpec.scala
@@ -40,10 +40,9 @@ trait BaseDBSpec extends BeforeAndAfterAll {
   }
 
   def insertHashtables(items: Iterable[HashtableItem], mode: String): Unit = {
-    val hashtablesTable = s"${Gemini.tables.hashtables}_${mode}"
     val cols = Gemini.tables.hashtablesCols
     items.foreach { case HashtableItem(ht, v, sha1) =>
-      val cql = s"""INSERT INTO $keyspace.${hashtablesTable}
+      val cql = s"""INSERT INTO $keyspace.${Gemini.tables.hashtables(mode)}
         (${cols.hashtable}, ${cols.value}, ${cols.sha})
         VALUES ($ht, $v, '$sha1')"""
       cassandra.execute(cql)
@@ -51,13 +50,20 @@ trait BaseDBSpec extends BeforeAndAfterAll {
   }
 
   def insertDocFreq(docFreq: OrderedDocFreq, mode: String): Unit = {
-    val cols = Gemini.tables.docFreqCols
-    val javaMap = docFreq.df.asJava
-
+    val docsCols = Gemini.tables.featuresDocsCols
     cassandra.execute(
-      s"INSERT INTO $keyspace.${Gemini.tables.docFreq} (${cols.id}, ${cols.docs}, ${cols.df}) VALUES (?, ?, ?)",
-      mode, int2Integer(docFreq.docs), javaMap
+      s"INSERT INTO $keyspace.${Gemini.tables.featuresDocs} (${docsCols.id}, ${docsCols.docs}) VALUES (?, ?)",
+      mode, int2Integer(docFreq.docs)
     )
+
+    val freqCols = Gemini.tables.featuresFreqCols
+    docFreq.df.foreach { case(feature, weight) =>
+      cassandra.execute(
+        s"INSERT INTO $keyspace.${Gemini.tables.featuresFreq}" +
+          s"(${freqCols.id}, ${freqCols.feature}, ${freqCols.weight}) VALUES (?, ?, ?)",
+        mode, feature, int2Integer(weight)
+      )
+    }
   }
 
   override def afterAll(): Unit = {