diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index b721070..f3d362f 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -25,6 +25,12 @@ jobs:
         registry: private.docker.xenit.eu
         username: ${{ secrets.CLOUDSMITH_USER }}
         password: ${{ secrets.CLOUDSMITH_APIKEY }}
+    - name: Build docker image
+      uses: gradle/gradle-build-action@v2.3.3
+      env:
+        BRANCH_NAME: ${{ github.ref_name }}
+      with:
+        arguments: buildDockerImage
     - name: Publish docker image
       if: ${{ startsWith(github.ref, 'refs/heads/master') }}
       uses: gradle/gradle-build-action@v2.3.3
diff --git a/build.gradle b/build.gradle
index 7009ef7..365be54 100644
--- a/build.gradle
+++ b/build.gradle
@@ -6,7 +6,7 @@ plugins {
 ext {
     base_img = 'open-source.docker.xenit.eu/oracle-python'
     base_img_version = 'main-2.1.1'
-    img_version = '2.0.0'
+    img_version = '2.1.0'
 }
 
 createDockerFile {
diff --git a/src/main/docker/docker_root/swarmclean.py b/src/main/docker/docker_root/swarmclean.py
index 92399c0..0482add 100755
--- a/src/main/docker/docker_root/swarmclean.py
+++ b/src/main/docker/docker_root/swarmclean.py
@@ -13,6 +13,7 @@
 import records
 from dataclasses import dataclass, asdict
 import humanfriendly
+import binascii
 
 sys.path.insert(0,sys.path[0]+'/castorsdk')
 import scspHeaders
@@ -351,7 +352,7 @@ def list_bucket_contents_filtered(self, filter_function, max_batch_size):
       objects = response.json()
 
       if not objects:
-        return object_list
+        return { 'list': object_list, 'size': batch_size }
 
       for object in objects:
         swarm_object = SwarmObject(**object)
@@ -456,7 +457,16 @@ def __init__(self, args):
 
   def isDeletionCandidate(self, swarm_object):
     if args.filter_method == 'alfresco_db':
-      result = self.alfresco_db.query_single_value("select count(*) from alf_content_url where content_url like :object_name", {'object_name': f"%/{swarm_object.name}"}) == 0
+      content_url_short = swarm_object.name[-12:]
+      content_url_crc = binascii.crc32(bytes(f"swarm://{self.args.swarm_domain}/{swarm_object.name}", 'ascii'))
+      # table has an index on content_url_short + content_url_crc
+      result = self.alfresco_db.query_single_value(
+        "select count(*) from alf_content_url where content_url_short = :content_url_short and content_url_crc = :content_url_crc", 
+        {
+          'content_url_short': content_url_short,
+          'content_url_crc': content_url_crc
+        }
+      ) == 0
     elif args.filter_method == 'regex':
       result = self.filterRegex.match(swarm_object.name)
     logging.trace(f"filter { swarm_object.name }: { bool(result) } - size { humanfriendly.format_size(swarm_object.bytes, binary=True) }")