diff --git a/async/src/main/scala/lightdb/async/AsyncCollection.scala b/async/src/main/scala/lightdb/async/AsyncCollection.scala
index f7b6bcff..a908d13f 100644
--- a/async/src/main/scala/lightdb/async/AsyncCollection.scala
+++ b/async/src/main/scala/lightdb/async/AsyncCollection.scala
@@ -90,7 +90,7 @@ case class AsyncCollection[Doc <: Document[Doc], Model <: DocumentModel[Doc]](un
 
   def list(implicit transaction: Transaction[Doc]): IO[List[Doc]] = stream.compile.toList
 
-  def query: AsyncQuery[Doc, Model] = AsyncQuery(underlying)
+  def query: AsyncQuery[Doc, Model] = AsyncQuery(this)
 
   def truncate()(implicit transaction: Transaction[Doc]): IO[Int] = IO.blocking(underlying.truncate())
 
diff --git a/async/src/main/scala/lightdb/async/AsyncQuery.scala b/async/src/main/scala/lightdb/async/AsyncQuery.scala
index b5257b29..efb16580 100644
--- a/async/src/main/scala/lightdb/async/AsyncQuery.scala
+++ b/async/src/main/scala/lightdb/async/AsyncQuery.scala
@@ -17,7 +17,7 @@ import lightdb.store.Conversion
 import lightdb.transaction.Transaction
 import lightdb.util.GroupedIterator
 
-case class AsyncQuery[Doc <: Document[Doc], Model <: DocumentModel[Doc]](collection: Collection[Doc, Model],
+case class AsyncQuery[Doc <: Document[Doc], Model <: DocumentModel[Doc]](asyncCollection: AsyncCollection[Doc, Model],
                                                                          filter: Option[Filter[Doc]] = None,
                                                                          sort: List[Sort] = Nil,
                                                                          offset: Int = 0,
@@ -26,6 +26,8 @@ case class AsyncQuery[Doc <: Document[Doc], Model <: DocumentModel[Doc]](collect
                                                                          scoreDocs: Boolean = false,
                                                                          minDocScore: Option[Double] = None,
                                                                          facets: List[FacetQuery[Doc]] = Nil) { query =>
+  protected def collection: Collection[Doc, Model] = asyncCollection.underlying
+
   def toQuery: Query[Doc, Model] = Query[Doc, Model](collection, filter, sort, offset, limit, countTotal, scoreDocs, minDocScore, facets)
 
   def scored: AsyncQuery[Doc, Model] = copy(scoreDocs = true)
@@ -217,6 +219,19 @@ case class AsyncQuery[Doc <: Document[Doc], Model <: DocumentModel[Doc]](collect
       apply(Conversion.Distance(f(collection.model), from, sort, radius))
   }
 
+  def process(establishLock: Boolean = true)
+             (f: Doc => IO[Doc])
+             (implicit transaction: Transaction[Doc]): IO[Int] = stream
+    .docs
+    .evalMap { doc =>
+      asyncCollection.withLock(doc._id, IO.pure(Some(doc)), establishLock) { current =>
+        f(current.getOrElse(doc)).map(Some.apply)
+      }
+    }
+    .compile
+    .count
+    .map(_.toInt)
+
   def toList(implicit transaction: Transaction[Doc]): IO[List[Doc]] = stream.docs.compile.toList
 
   def first(implicit transaction: Transaction[Doc]): IO[Option[Doc]] = stream.docs.take(1).compile.last
diff --git a/core/src/main/scala/lightdb/Query.scala b/core/src/main/scala/lightdb/Query.scala
index 359e5bbf..0ff60c8d 100644
--- a/core/src/main/scala/lightdb/Query.scala
+++ b/core/src/main/scala/lightdb/Query.scala
@@ -140,6 +140,18 @@ case class Query[Doc <: Document[Doc], Model <: DocumentModel[Doc]](collection:
     }
   }
 
+  def process(establishLock: Boolean = true)
+             (f: Doc => Doc)
+             (implicit transaction: Transaction[Doc]): Unit = if (establishLock) {
+    search.docs.iterator.foreach { doc =>
+      collection.lock(doc._id, Some(doc)) { current =>
+        Some(f(current.getOrElse(doc)))
+      }
+    }
+  } else {
+    search.docs.iterator.foreach(f)
+  }
+
   def iterator(implicit transaction: Transaction[Doc]): Iterator[Doc] = search.docs.iterator
 
   def toList(implicit transaction: Transaction[Doc]): List[Doc] = search.docs.list