Added minimal docs.

- The newly introduced CLI args are not documented in RunningDaphneLocally.md, because the new feature is experimental and not the first thing we want users to look at.
- Instead, added a minimal page in the developer docs.

Author: pdamme

doc/README.md

@@ -23,6 +23,7 @@
 
 * [Creating release artifacts](ReleaseScripts.md)
 * [Maintaining GPG signing keys](GPG-signing-keys.md)
+* [Recording Data Properties](/doc/development/PropertyRecording.md)
 
 ### How-tos and Guidelines
 

doc/RunningDaphneLocally.md

@@ -80,14 +80,6 @@ Note that some of the more specific options are described in the documentation p
 
     Turns on the automatic selection of a suitable matrix representation (currently dense or sparse (CSR)). *Experimental feature.*
 
-- **`--enable_property_recording`**
-
-    Enables recording of certain properties (currently only sparsity) from all matrix result objects in the Intermediate Representation (IR). The recorded properties are saved in a JSON file named properties.json located in the root directory of Daphne.
-
-- **`--enable_property_insert`** and **`--properties_file_path=<path/to/propertiesFile>`**
-
-    Allows the insertion of previously recorded properties into operations with matrix results from a JSON file. By default, the file used is properties.json in the Daphne root directory. Optionally, a different file can be specified using the `--properties_file_path` argument.
-
 ## Return Codes
 
 If `daphne` terminates normally, one of the following status codes is returned:

doc/development/PropertyRecording.md

@@ -0,0 +1,40 @@
+<!--
+Copyright 2025 The DAPHNE Consortium
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+-->
+
+# Recording Data Properties
+
+There is an experimental feature for recording the true data properties of intermediate results at run-time and re-inserting them in a subsequent run of DAPHNE.
+
+By default, this feature is turned off.
+Recording data properties can be turned on by invoking `daphne` with `--enable-property-recording`.
+Inserting data properties recorded in a previous execution of `daphne` can be turned on with `--enable-property-insert`.
+These two options are mutually exclusive.
+The recorded true data properties are stored to/loaded from a simple JSON file whose path is specified by `--properties-file-path` (default: `properties.json`).
+See also `daphne --help` for some help on these options.
+
+## Possible Uses of this Feature
+
+- Recording: Detailed insights into the data properties of intermediate results to find potential for optimizations by exploiting these data properties.
+- Insertion: Find out how DAPHNE performs when it has precise knowledge of the true data properties (no unknowns, no inaccurate compile-time estimates).
+- ...
+
+## Current Limitations
+
+- Only one data property is recorded: sparsity; more properties could be added in the future.
+- Only matrix-typed intermediate results are considered; scalars and frames could be added in the future.
+- Only intermediates produced in the `main` function of DaphneIR are considered; intermediates inside UDFs could be considered in the future.
+- Control-flow constructs like if-then-else and loops are viewed as black boxes, i.e., the data properties of their results are recorded/inserted, but not those of intermediates created *inside* these constructs; in the future, we could consider those, too.
+- ...

mkdocs.yml

@@ -81,3 +81,4 @@ nav:
     - development/WriteDocs.md
     - development/Testing.md
     - development/InstallPythonLibsInContainer.md
+    - development/PropertyRecording.md