docs: clarify plpython SD and GD dictionary behavior

Reported-by: Adam Bielański
Discussion: https://postgr.es/m/153484305538.1370.7605856225879294548@wrigleys.postgresql.org

Backpatch-through: 9.3

diff --git a/doc/src/sgml/plpython.sgml b/doc/src/sgml/plpython.sgml
index 905e757ab6cf867451c530d17629bbf2a6d82080..9929b84e6e35ac3ec6c570dbbe519d24a7600fe4 100644 (file)
--- a/doc/src/sgml/plpython.sgml
+++ b/doc/src/sgml/plpython.sgml
@@ -734,9 +734,9 @@ SELECT * FROM multiout_simple_setof(3);
   <title>Sharing Data</title>
   <para>
    The global dictionary <varname>SD</varname> is available to store
-   data between function calls.  This variable is private static data.
+   private data between repeated calls to the same function.
    The global dictionary <varname>GD</varname> is public data,
-   available to all Python functions within a session.  Use with
+   that is available to all Python functions within a session;  use with
    care.<indexterm><primary>global data</>
    <secondary>in PL/Python</></indexterm>
   </para>