[Doc]Document all the currently supported SQL operation for memory co…

…nnector

presto-docs/src/main/sphinx/connector/memory.rst

@@ -5,7 +5,6 @@ Memory Connector
 The Memory connector stores all data and metadata in RAM on workers
 and both are discarded when Presto restarts.
 
-
 Configuration
 -------------
 
@@ -41,23 +40,81 @@ Drop table::
 
     DROP TABLE memory.default.nation;
 
+SQL Support
+-----------
+
+The Memory connector allows querying and creating tables and schemas in memory. Here are some examples of the SQL operations supported:
+
+CREATE SCHEMA
+^^^^^^^^^^^^^
+
+Create a new schema named ``default1``:
+
+.. code-block:: sql
+
+     CREATE SCHEMA memory.default1;
+
+CREATE TABLE
+^^^^^^^^^^^^
+
+Create a new table named ``my_table`` in the ``default1`` schema:
+
+.. code-block:: sql
+
+    CREATE TABLE memory.default1.my_table (id integer, name varchar, age integer);
+
+INSERT INTO
+^^^^^^^^^^^
+
+Insert data into the ``my_table`` table:
+
+.. code-block:: sql
+
+    INSERT INTO memory.default1.my_table (id, name, age) VALUES (1, 'John Doe', 30);
+
+SELECT
+^^^^^^
+
+Select data from the ``my_table`` table:
+
+.. code-block:: sql
+
+   SELECT * FROM memory.default1.my_table;
+
+DROP TABLE
+^^^^^^^^^^
+
+To delete an existing table:
+
+.. code-block:: sql
+
+    DROP TABLE memory.default.nation;
+
+.. note:: After using ``DROP TABLE``, memory is not released immediately. It is released after the next write access to the memory connector.
 
 Memory Connector Limitations
 ----------------------------
 
-    * After ``DROP TABLE`` memory is not released immediately. It is
-      released after next write access to memory connector.
-    * When one worker fails/restarts all data that were stored in its
-      memory will be lost forever. To prevent silent data loss this
-      connector will throw an error on any read access to such
-      corrupted table.
-    * When query fails for any reason during writing to memory table,
-      table will be in undefined state. Such table should be dropped
-      and recreated manually. Reading attempt from such table may fail
-      or may return partial data.
-    * When coordinator fails/restarts all metadata about tables will
-      be lost, but tables' data will be still present on the workers
-      however they will be inaccessible.
-    * This connector will not work properly with multiple
-      coordinators, since each coordinator will have a different
-      metadata.
+The following SQL statements are not supported:
+
+* :doc:`/sql/alter-table`
+* :doc:`/sql/delete`
+* :doc:`/sql/update`
+
+Limitations
+^^^^^^^^^^^
+
+* When one worker fails or restarts, all data stored in its
+  memory is lost forever. To prevent silent data loss, this
+  connector generates an error on any read access to such a
+  corrupted table.
+* When a query fails for any reason during writing to memory table,
+  the table is in undefined state. Such a table should be dropped
+  and recreated manually. Reading from such tables may fail
+  or may return partial data.
+* When the coordinator fails or restarts, all metadata about tables is
+  lost. The tables' data is still present on the workers,
+  but that data is inaccessible.
+* This connector will not work properly with multiple
+  coordinators, because each coordinator has a different
+  metadata.