diff --git a/afs-cassandra/src/main/java/com/powsybl/afs/cassandra/CassandraAppStorage.java b/afs-cassandra/src/main/java/com/powsybl/afs/cassandra/CassandraAppStorage.java
index 764f3eea..dd0dcc33 100644
--- a/afs-cassandra/src/main/java/com/powsybl/afs/cassandra/CassandraAppStorage.java
+++ b/afs-cassandra/src/main/java/com/powsybl/afs/cassandra/CassandraAppStorage.java
@@ -864,7 +864,7 @@ private DecompressOnceBinaryDataInputStream(UUID nodeUuid, String name, Row firs
                 ByteArrayInputStream bais = new ByteArrayInputStream(tmp.toByteArray());
                 gzis = new GZIPInputStream(bais);
             } catch (IOException e) {
-                e.printStackTrace();
+                throw new UncheckedIOException(e);
             }
         }
 
diff --git a/afs-cassandra/src/test/java/com/powsybl/afs/cassandra/CassandraDataSplitTest.java b/afs-cassandra/src/test/java/com/powsybl/afs/cassandra/CassandraDataSplitTest.java
index 11f3a57d..0941ffe9 100644
--- a/afs-cassandra/src/test/java/com/powsybl/afs/cassandra/CassandraDataSplitTest.java
+++ b/afs-cassandra/src/test/java/com/powsybl/afs/cassandra/CassandraDataSplitTest.java
@@ -67,13 +67,8 @@ public void test() throws IOException {
         assertTrue(storage.removeData(nodeInfo.getId(), "a"));
         assertTrue(storage.getDataNames(nodeInfo.getId()).isEmpty());
         assertFalse(storage.readBinaryData(nodeInfo.getId(), "a").isPresent());
-//    }
-//
-//    @Test
-//    public void testGzipOnce() throws IOException {
+
         String data = "aaaaaaaaaabbbbbbbbbbccccccccccddddddddddddddddddeeeeeeeeeeeeeeeeeeeeefffffffffffffffffffffffff";
-//        CassandraAppStorage storage = new CassandraAppStorage("test", () -> new CassandraTestContext(cassandraCQLUnit),
-//                new CassandraAppStorageConfig().setBinaryDataChunkSize(10), new InMemoryEventsBus());
         NodeInfo rootNodeId2 = storage.createRootNodeIfNotExists("test", "folder");
         NodeInfo nodeInfo2 = storage.createNode(rootNodeId2.getId(), "test1", "folder", "", 0, new NodeGenericMetadata());
         try (OutputStream os = storage.writeBinaryData(nodeInfo2.getId(), "gzipOnce", AppStorage.CompressionMode.ONCE)) {
diff --git a/afs-ext-base/src/main/java/com/powsybl/afs/ext/base/ImportedCaseBuilder.java b/afs-ext-base/src/main/java/com/powsybl/afs/ext/base/ImportedCaseBuilder.java
index c1dca707..2560d525 100644
--- a/afs-ext-base/src/main/java/com/powsybl/afs/ext/base/ImportedCaseBuilder.java
+++ b/afs-ext-base/src/main/java/com/powsybl/afs/ext/base/ImportedCaseBuilder.java
@@ -56,6 +56,8 @@ public class ImportedCaseBuilder implements ProjectFileBuilder<ImportedCase> {
 
     private Importer importer;
 
+    private AppStorage.CompressionMode mode = AppStorage.CompressionMode.MULTI;
+
     private final Properties parameters = new Properties();
 
     public ImportedCaseBuilder(ProjectFileBuildContext context, ImportersLoader importersLoader, ImportConfig importConfig) {
@@ -122,6 +124,11 @@ public ImportedCaseBuilder withParameters(Map<String, String> parameters) {
         return this;
     }
 
+    public ImportedCaseBuilder setCompressMode(AppStorage.CompressionMode mode) {
+        this.mode = Objects.requireNonNull(mode);
+        return this;
+    }
+
     @Override
     public ImportedCase build() {
         if (dataSource == null) {
@@ -140,7 +147,7 @@ public ImportedCase build() {
                 new NodeGenericMetadata().setString(ImportedCase.FORMAT, importer.getFormat()));
 
         // store case data
-        importer.copy(dataSource, new AppStorageDataSource(context.getStorage(), info.getId(), info.getName()));
+        importer.copy(dataSource, new AppStorageDataSource(context.getStorage(), info.getId(), info.getName(), mode));
 
         // store parameters
         try (Writer writer = new OutputStreamWriter(context.getStorage().writeBinaryData(info.getId(), ImportedCase.PARAMETERS), StandardCharsets.UTF_8)) {
diff --git a/afs-storage-api/src/main/java/com/powsybl/afs/storage/AppStorageDataSource.java b/afs-storage-api/src/main/java/com/powsybl/afs/storage/AppStorageDataSource.java
index 836c351b..4fb33c2a 100755
--- a/afs-storage-api/src/main/java/com/powsybl/afs/storage/AppStorageDataSource.java
+++ b/afs-storage-api/src/main/java/com/powsybl/afs/storage/AppStorageDataSource.java
@@ -6,6 +6,10 @@
  */
 package com.powsybl.afs.storage;
 
+import com.powsybl.commons.datasource.DataSource;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
@@ -15,11 +19,6 @@
 import java.util.regex.Pattern;
 import java.util.stream.Collectors;
 
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
-import com.powsybl.commons.datasource.DataSource;
-
 /**
  * A datasource corresponding to a data blob stored in the file system.
  * A data blob is associated to a node and a name identifying it among data blobs of this node.
@@ -30,6 +29,10 @@ public class AppStorageDataSource implements DataSource {
 
     private static final String SEPARATOR = "__";
 
+    private static final AppStorage.CompressionMode DEFAULT_COMPRESS_MODE = AppStorage.CompressionMode.MULTI;
+
+    private final AppStorage.CompressionMode compressMode;
+
     public interface Name {
 
         static Name parse(String text) {
@@ -132,9 +135,14 @@ public String toString() {
     private final String nodeName;
 
     public AppStorageDataSource(AppStorage storage, String nodeId, String nodeName) {
+        this(storage, nodeId, nodeName, DEFAULT_COMPRESS_MODE);
+    }
+
+    public AppStorageDataSource(AppStorage storage, String nodeId, String nodeName, AppStorage.CompressionMode mode) {
         this.storage = Objects.requireNonNull(storage);
         this.nodeId = Objects.requireNonNull(nodeId);
         this.nodeName = Objects.requireNonNull(nodeName);
+        this.compressMode = Objects.requireNonNull(mode);
     }
 
     @Override
@@ -147,7 +155,7 @@ public OutputStream newOutputStream(final String suffix, final String ext, boole
         if (append) {
             throw new UnsupportedOperationException("Append mode not supported");
         }
-        return storage.writeBinaryData(nodeId, new SuffixAndExtension(suffix, ext).toString());
+        return storage.writeBinaryData(nodeId, new SuffixAndExtension(suffix, ext).toString(), compressMode);
     }
 
     @Override
@@ -156,7 +164,7 @@ public OutputStream newOutputStream(String fileName, boolean append) {
         if (append) {
             throw new UnsupportedOperationException("Append mode not supported");
         }
-        return storage.writeBinaryData(nodeId, new FileName(fileName).toString());
+        return storage.writeBinaryData(nodeId, new FileName(fileName).toString(), compressMode);
     }
 
     @Override