docs: Add AsyncDataCache and SSD cache documentation

velox/docs/develop.rst

@@ -33,3 +33,4 @@ This guide is intended for Velox contributors and developers of Velox-based appl
     develop/TpchBenchmark
     develop/window
     develop/dynamic-loading
+    develop/cache

velox/docs/develop/cache.rst

@@ -0,0 +1,39 @@
+=====================================
+AsyncDataCache (In Memory Data Cache)
+=====================================
+
+Background
+----------
+Velox provides a transparent data cache (AsyncDataCache) to accelerate table scans operators through hot data reuse and prefetch algorithms. 
+This data cache is integrated with the memory system to achieve dynamic memory sharing between the data cache and query memory. 
+When a query fails to allocate memory, Velox retries the allocation by shrinking the data cache. 
+Therefore, the data cache size is automatically adjusted in response to the query memory usage change. 
+See `Memory Management - Velox Documentation <https://facebookincubator.github.io/velox/develop/memory.html>`_  
+for more information about Velox's data cache.
+
+Configuration Properties
+------------------------
+See `Configuration Properties 
+<https://github.com/prestodb/presto/blob/master/presto-docs/src/main/sphinx/presto_cpp/properties.rst#cache-properties>`_ 
+for AsyncDataCache related configuration properties.
+
+=========
+SSD Cache
+=========
+
+Background
+----------
+The in-memory data cache (AsyncDataCache) is configured to use SSD when provided.
+The SSD serves as an extension for the AsyncDataCache.
+This helps mitigate the number of reads from slower storage.
+
+Configuration Properties
+------------------------
+See `Configuration Properties 
+<https://github.com/prestodb/presto/blob/master/presto-docs/src/main/sphinx/presto_cpp/properties.rst#cache-properties>`_ 
+for SSD Cache related configuration properties.
+
+Metrics
+-------
+There are SSD cache relevant metrics that Velox emits during query execution and runtime. 
+See `Debugging Metrics <./debugging/metrics.rst>`_ and `Monitoring Metrics <../monitoring/metrics.rst>`_ for more details.