Modify the handling of RAISE without parameters so that the error it throws

can be caught in the same places that could catch an ordinary RAISE ERROR
in the same location.  The previous coding insisted on throwing the error
from the block containing the active exception handler; which is arguably
more surprising, and definitely unlike Oracle's behavior.

Not back-patching, since this is a pretty obscure corner case.  The risk
of breaking somebody's code in a minor version update seems to outweigh
any possible benefit.

Piyush Newe, reviewed by David Fetter

1 files changed, 16 insertions, 5 deletions

diff --git a/doc/src/sgml/plpgsql.sgml b/doc/src/sgml/plpgsql.sgml
index adc56a7a0e7..f60273b6998 100644
--- a/doc/src/sgml/plpgsql.sgml
+++ b/doc/src/sgml/plpgsql.sgml
@@ -1,4 +1,4 @@
-<!-- $PostgreSQL: pgsql/doc/src/sgml/plpgsql.sgml,v 1.156 2010/07/29 19:34:40 petere Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/plpgsql.sgml,v 1.157 2010/08/09 02:25:05 tgl Exp $ -->
 
 <chapter id="plpgsql">
   <title><application>PL/pgSQL</application> - <acronym>SQL</acronym> Procedural Language</title>
@@ -2160,7 +2160,7 @@ BEGIN
                    || quote_ident(mviews.mv_name) || ' ...');
         EXECUTE 'TRUNCATE TABLE ' || quote_ident(mviews.mv_name);
         EXECUTE 'INSERT INTO '
-                   || quote_ident(mviews.mv_name) || ' ' 
+                   || quote_ident(mviews.mv_name) || ' '
                    || mviews.mv_query;
     END LOOP;
 
@@ -2523,7 +2523,7 @@ OPEN <replaceable>unbound_cursorvar</replaceable> <optional> <optional> NO </opt
        <para>
         An example:
 <programlisting>
-OPEN curs1 FOR EXECUTE 'SELECT * FROM ' || quote_ident(tabname) 
+OPEN curs1 FOR EXECUTE 'SELECT * FROM ' || quote_ident(tabname)
                                         || ' WHERE col1 = $1' USING keyvalue;
 </programlisting>
         In this example, the table name is inserted into the query textually,
@@ -3012,10 +3012,21 @@ RAISE unique_violation USING MESSAGE = 'Duplicate user ID: ' || user_id;
     The last variant of <command>RAISE</> has no parameters at all.
     This form can only be used inside a <literal>BEGIN</> block's
     <literal>EXCEPTION</> clause;
-    it causes the error currently being handled to be re-thrown to the
-    next enclosing block.
+    it causes the error currently being handled to be re-thrown.
    </para>
 
+   <note>
+    <para>
+     Before <productname>PostgreSQL</> 9.1, <command>RAISE</> without
+     parameters was interpreted as re-throwing the error from the block
+     containing the active exception handler.  Thus an <literal>EXCEPTION</>
+     clause nested within that handler could not catch it, even if the
+     <command>RAISE</> was within the nested <literal>EXCEPTION</> clause's
+     block. This was deemed surprising as well as being incompatible with
+     Oracle's PL/SQL.
+    </para>
+   </note>
+
    <para>
     If no condition name nor SQLSTATE is specified in a
     <command>RAISE EXCEPTION</command> command, the default is to use