diff --git a/Array.cc b/Array.cc
index 36b3a6e9c..a57a274ce 100644
--- a/Array.cc
+++ b/Array.cc
@@ -1337,6 +1337,8 @@ void Array::dump(std::ostream &strm) const {
  */
 void Array::set_var_storage_info(const var_storage_info &my_vs_info) {
 
+    vs_info.has_filled_chunks = my_vs_info.has_filled_chunks;
+
     vs_info.filter = my_vs_info.filter;
 
     for (const auto &def_lev : my_vs_info.deflate_levels)
diff --git a/Array.h b/Array.h
index 472089621..27b60acb0 100644
--- a/Array.h
+++ b/Array.h
@@ -191,6 +191,7 @@ class Array : public Vector {
 
     /** @brief Storage layout and filter metadata for direct-I/O reads. */
     struct var_storage_info {
+        bool has_filled_chunks;                  ///< Whether this array has chunks that only contain filled values.
         string filter;                           ///< Filter pipeline description.
         vector<unsigned int> deflate_levels;     ///< Deflate levels per filter stage.
         vector<size_t> chunk_dims;               ///< Chunk dimensions in row-major order.
@@ -205,6 +206,8 @@ class Array : public Vector {
     bool direct_io_flag = false;
     var_storage_info vs_info;
 
+    float storage_size_ratio = 1;
+
     void update_dimension_pointers(D4Group *grp);
     void print_dim_element(const XMLWriter &xml, const dimension &d, bool constrained);
 
@@ -502,6 +505,17 @@ class Array : public Vector {
      * @param my_vs_info New storage metadata.
      */
     void set_var_storage_info(const var_storage_info &my_vs_info);
+
+    // The following methods are for the applications that care about storage size.
+
+    /** @brief Returns the ratio of logical size to the real storage size for this array. */
+    float get_storage_size_ratio() const { return storage_size_ratio; }
+
+    /**
+     * @brief set the ratio of the logical size to the real storage size for this array.
+     * @param the ratio of the logical size to the real storage size for this array.
+     */
+    void set_storage_size_ratio(float sr) { storage_size_ratio = sr; }
 };
 
 } // namespace libdap