diff --git a/doc/feindesign/server_architektur.rs b/doc/feindesign/server_architektur.rs
index 572b161..72617d3 100644
--- a/doc/feindesign/server_architektur.rs
+++ b/doc/feindesign/server_architektur.rs
@@ -80,6 +80,13 @@ pub mod persistency {
     use std::io;
     use std::path::{Path, PathBuf};
     use std::sync::Arc;
+    
+    pub type TextureFileResult = Result< Arc<Vec<u8>> , TextureFileError>
+    pub enum TextureFileError {
+        NotFound,
+        IOError(io::Error),
+        ImgError(::image::Error),
+    }
 
     pub struct DataStore {
         // private attributes
@@ -98,14 +105,41 @@ pub mod persistency {
             unimplemented!()
         }
 
-        // TODO: think
-
-        pub fn search(&mut self, query: &self::search::Query) -> Vec<Texture> {
+        pub fn query(&mut self, query: &self::search::Query) -> Vec<Texture> {
             unimplemented!();
             // calls self::search::search(... )
         }
-    }
 
+        /// returns true if successful
+        pub fn delete(&mut self, tex: &Texture) -> bool {
+            unimplemented!();
+        }
+
+        pub fn insert(&mut self, tex: Texture) -> bool {
+            unimplemented!();
+        }
+
+        pub fn by_name<'a>(&'a self, name: &str) -> &'a Texture {
+            unimplemented!();
+        }
+
+        pub fn by_id<'a, 'b>(&'a self, id: &'b str) -> &'a Texture {
+            unimplemented!();
+        }
+
+        pub fn has_hash(&self, hash: &Sha256) -> bool {
+            unimplemented!();
+        }
+
+        pub fn get_texture_file(&mut self, hash: &Sha256) -> TextureFileResult {
+            unimplemented!();
+        }
+
+        pub fn get_texture_preview(&mut self, hash: &Sha256) -> TextureFileResult {
+            unimplemented!();
+        }
+    }
+    
     pub use self::search::Query;
 
     mod search {
@@ -146,23 +180,21 @@ pub mod persistency {
         }
     }
 
-}
+    pub mod image_convert {
+        use crate::model::*;
 
-pub mod image_convert {
-    use crate::model::*;
+        pub struct ConvertConfig {
+            pub desired_size: (usize, usize),
+        }
 
-    pub struct ConvertConfig {
-        pub desired_size: (usize, usize),
+        pub fn generate_preview(
+            input: &[u8],
+            format: TextureFormat,
+            config: &ConvertConfig,
+        ) -> ::image::ImageResult<Vec<u8>> {
+            unimplemented!()
+        }
     }
-
-    pub fn generate_preview(
-        input: &[u8],
-        format: TextureFormat,
-        config: &ConvertConfig,
-    ) -> ::image::ImageResult<Vec<u8>> {
-        unimplemented!()
-    }
-
 }
 
 pub mod main {