On 31.01.23 12:07, Peter Eisentraut wrote:
Applying this patch, your test queries seem to work correctly.
Great!
This is quite WIP, especially because there's a couple of scenarios
uncovered by tests that I'd like to ensure correctness about, but if you
would like to continue adding tests for extended query and dynamic
result sets, it may be helpful.
I should note that it is debatable whether my patch extends the extended
query protocol or just uses it within its existing spec but in new ways.
It just happened to work in old libpq versions without any changes. So
you should keep that in mind as you refine your patch, since the way the
protocol has been extended/creatively-used is still subject to review.
After some consideration, I have an idea how to proceed with this. I
have split my original patch into two incremental patches. The first
patch implements the original feature, but just for the simple query
protocol. (The simple query protocol already supports multiple result
sets.) Attempting to return dynamic result sets using the extended
query protocol will result in an error. The second patch then adds the
extended query protocol support back in, but it still has the issues
with libpq that we are discussing.
I think this way we could have a chance to get the first part into PG16
or early into PG17, and then the second part can be worked on with less
stress. This would also allow us to consider a minor protocol version
bump, and the handling of binary format for dynamic result sets (like
https://commitfest.postgresql.org/42/3777/), and maybe some other issues.
The attached patches are the same as before, rebased over master and
split up as described. I haven't done any significant work on the
contents, but I will try to get the 0001 patch into a more polished
state soon.From 1e22417c8cfa6aa230a21a6aa25b166b3b4bbecb Mon Sep 17 00:00:00 2001
From: Peter Eisentraut <pe...@eisentraut.org>
Date: Mon, 20 Feb 2023 12:09:24 +0100
Subject: [PATCH v7 1/2] Dynamic result sets from procedures
Declaring a cursor WITH RETURN in a procedure makes the cursor's data be
returned as a result of the CALL invocation. The procedure needs to
be declared with the DYNAMIC RESULT SETS attribute.
Discussion:
https://www.postgresql.org/message-id/flat/6e747f98-835f-2e05-cde5-86ee444a7...@2ndquadrant.com
---
doc/src/sgml/catalogs.sgml | 10 ++
doc/src/sgml/information_schema.sgml | 3 +-
doc/src/sgml/plpgsql.sgml | 27 ++++-
doc/src/sgml/ref/alter_procedure.sgml | 12 +++
doc/src/sgml/ref/create_procedure.sgml | 14 +++
doc/src/sgml/ref/declare.sgml | 34 +++++-
src/backend/catalog/information_schema.sql | 2 +-
src/backend/catalog/pg_aggregate.c | 3 +-
src/backend/catalog/pg_proc.c | 4 +-
src/backend/catalog/sql_features.txt | 2 +-
src/backend/commands/functioncmds.c | 79 ++++++++++++--
src/backend/commands/portalcmds.c | 23 ++++
src/backend/commands/typecmds.c | 12 ++-
src/backend/parser/gram.y | 18 +++-
src/backend/tcop/postgres.c | 37 ++++++-
src/backend/utils/errcodes.txt | 1 +
src/backend/utils/mmgr/portalmem.c | 48 +++++++++
src/bin/pg_dump/pg_dump.c | 16 ++-
src/include/catalog/pg_proc.h | 6 +-
src/include/commands/defrem.h | 1 +
src/include/nodes/parsenodes.h | 1 +
src/include/parser/kwlist.h | 2 +
src/include/utils/portal.h | 12 +++
src/pl/plpgsql/src/expected/plpgsql_call.out | 78 ++++++++++++++
src/pl/plpgsql/src/pl_exec.c | 6 ++
src/pl/plpgsql/src/pl_gram.y | 58 ++++++++--
src/pl/plpgsql/src/pl_unreserved_kwlist.h | 2 +
src/pl/plpgsql/src/sql/plpgsql_call.sql | 46 ++++++++
.../regress/expected/create_procedure.out | 100 +++++++++++++++++-
src/test/regress/sql/create_procedure.sql | 65 +++++++++++-
30 files changed, 685 insertions(+), 37 deletions(-)
diff --git a/doc/src/sgml/catalogs.sgml b/doc/src/sgml/catalogs.sgml
index c1e4048054..5baec4dc3a 100644
--- a/doc/src/sgml/catalogs.sgml
+++ b/doc/src/sgml/catalogs.sgml
@@ -6041,6 +6041,16 @@ <title><structname>pg_proc</structname> Columns</title>
</para></entry>
</row>
+ <row>
+ <entry role="catalog_table_entry"><para role="column_definition">
+ <structfield>prodynres</structfield> <type>int4</type>
+ </para>
+ <para>
+ For procedures, this records the maximum number of dynamic result sets
+ the procedure may create. Otherwise zero.
+ </para></entry>
+ </row>
+
<row>
<entry role="catalog_table_entry"><para role="column_definition">
<structfield>pronargs</structfield> <type>int2</type>
diff --git a/doc/src/sgml/information_schema.sgml
b/doc/src/sgml/information_schema.sgml
index 350c75bc31..5fc9dc22ae 100644
--- a/doc/src/sgml/information_schema.sgml
+++ b/doc/src/sgml/information_schema.sgml
@@ -5885,7 +5885,8 @@ <title><structname>routines</structname> Columns</title>
<structfield>max_dynamic_result_sets</structfield>
<type>cardinal_number</type>
</para>
<para>
- Applies to a feature not available in
<productname>PostgreSQL</productname>
+ For a procedure, the maximum number of dynamic result sets. Otherwise
+ zero.
</para></entry>
</row>
diff --git a/doc/src/sgml/plpgsql.sgml b/doc/src/sgml/plpgsql.sgml
index 8897a5450a..0c0d77b0e6 100644
--- a/doc/src/sgml/plpgsql.sgml
+++ b/doc/src/sgml/plpgsql.sgml
@@ -3128,7 +3128,7 @@ <title>Declaring Cursor Variables</title>
Another way is to use the cursor declaration syntax,
which in general is:
<synopsis>
-<replaceable>name</replaceable> <optional> <optional> NO </optional> SCROLL
</optional> CURSOR <optional> ( <replaceable>arguments</replaceable> )
</optional> FOR <replaceable>query</replaceable>;
+<replaceable>name</replaceable> <optional> <optional> NO </optional> SCROLL
</optional> CURSOR <optional> <optional> WITH RETURN </optional> (
<replaceable>arguments</replaceable> ) </optional> FOR
<replaceable>query</replaceable>;
</synopsis>
(<literal>FOR</literal> can be replaced by <literal>IS</literal> for
<productname>Oracle</productname> compatibility.)
@@ -3136,6 +3136,10 @@ <title>Declaring Cursor Variables</title>
scrolling backward; if <literal>NO SCROLL</literal> is specified, backward
fetches will be rejected; if neither specification appears, it is
query-dependent whether backward fetches will be allowed.
+ If <literal>WITH RETURN</literal> is specified, the results of the
+ cursor, after it is opened, will be returned as a dynamic result set; see
+ <xref linkend="sql-declare"/> for details. (<literal>WITHOUT
+ RETURN</literal> can also be specified but has no effect.)
<replaceable>arguments</replaceable>, if specified, is a
comma-separated list of pairs <literal><replaceable>name</replaceable>
<replaceable>datatype</replaceable></literal> that define names to be
@@ -3215,7 +3219,7 @@ <title>Opening Cursors</title>
<title><command>OPEN FOR</command>
<replaceable>query</replaceable></title>
<synopsis>
-OPEN <replaceable>unbound_cursorvar</replaceable> <optional> <optional> NO
</optional> SCROLL </optional> FOR <replaceable>query</replaceable>;
+OPEN <replaceable>unbound_cursorvar</replaceable> <optional> <optional> NO
</optional> SCROLL </optional> <optional> WITH RETURN </optional> FOR
<replaceable>query</replaceable>;
</synopsis>
<para>
@@ -3233,8 +3237,9 @@ <title><command>OPEN FOR</command>
<replaceable>query</replaceable></title>
substituted is the one it has at the time of the
<command>OPEN</command>;
subsequent changes to the variable will not affect the cursor's
behavior.
- The <literal>SCROLL</literal> and <literal>NO SCROLL</literal>
- options have the same meanings as for a bound cursor.
+ The options <literal>SCROLL</literal>, <literal>NO SCROLL</literal>,
+ and <literal>WITH RETURN</literal> have the same meanings as for a
+ bound cursor.
</para>
<para>
@@ -3612,6 +3617,20 @@ <title>Returning Cursors</title>
COMMIT;
</programlisting>
</para>
+
+ <note>
+ <para>
+ Returning a cursor from a function as described here is a separate
+ mechanism from declaring a cursor <literal>WITH RETURN</literal>,
+ which automatically produces a result set for the client if the
+ cursor is left open when returning from the procedure. Both
+ mechanisms can be used to achieve similar effects. The differences
+ are mainly how the client application prefers to manage the cursors.
+ Furthermore, other SQL implementations have other programming models
+ that might map more easily to one or the other mechanism when doing a
+ migration.
+ </para>
+ </note>
</sect3>
</sect2>
diff --git a/doc/src/sgml/ref/alter_procedure.sgml
b/doc/src/sgml/ref/alter_procedure.sgml
index a4737a3439..2cdda7730e 100644
--- a/doc/src/sgml/ref/alter_procedure.sgml
+++ b/doc/src/sgml/ref/alter_procedure.sgml
@@ -34,6 +34,7 @@
<phrase>where <replaceable class="parameter">action</replaceable> is one
of:</phrase>
+ DYNAMIC RESULT SETS <replaceable
class="parameter">dynamic_result_sets</replaceable>
[ EXTERNAL ] SECURITY INVOKER | [ EXTERNAL ] SECURITY DEFINER
SET <replaceable class="parameter">configuration_parameter</replaceable> {
TO | = } { <replaceable class="parameter">value</replaceable> | DEFAULT }
SET <replaceable class="parameter">configuration_parameter</replaceable>
FROM CURRENT
@@ -158,6 +159,17 @@ <title>Parameters</title>
</listitem>
</varlistentry>
+ <varlistentry>
+ <term><literal>DYNAMIC RESULT SETS <replaceable
class="parameter">dynamic_result_sets</replaceable></literal></term>
+
+ <listitem>
+ <para>
+ Changes the dynamic result sets setting of the procedure. See <xref
+ linkend="sql-createprocedure"/> for more information.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry>
<term><literal><optional> EXTERNAL </optional> SECURITY
INVOKER</literal></term>
<term><literal><optional> EXTERNAL </optional> SECURITY
DEFINER</literal></term>
diff --git a/doc/src/sgml/ref/create_procedure.sgml
b/doc/src/sgml/ref/create_procedure.sgml
index 03a14c8684..1c99b00eef 100644
--- a/doc/src/sgml/ref/create_procedure.sgml
+++ b/doc/src/sgml/ref/create_procedure.sgml
@@ -24,6 +24,7 @@
CREATE [ OR REPLACE ] PROCEDURE
<replaceable class="parameter">name</replaceable> ( [ [ <replaceable
class="parameter">argmode</replaceable> ] [ <replaceable
class="parameter">argname</replaceable> ] <replaceable
class="parameter">argtype</replaceable> [ { DEFAULT | = } <replaceable
class="parameter">default_expr</replaceable> ] [, ...] ] )
{ LANGUAGE <replaceable class="parameter">lang_name</replaceable>
+ | DYNAMIC RESULT SETS <replaceable
class="parameter">dynamic_result_sets</replaceable>
| TRANSFORM { FOR TYPE <replaceable
class="parameter">type_name</replaceable> } [, ... ]
| [ EXTERNAL ] SECURITY INVOKER | [ EXTERNAL ] SECURITY DEFINER
| SET <replaceable class="parameter">configuration_parameter</replaceable>
{ TO <replaceable class="parameter">value</replaceable> | = <replaceable
class="parameter">value</replaceable> | FROM CURRENT }
@@ -176,6 +177,19 @@ <title>Parameters</title>
</listitem>
</varlistentry>
+ <varlistentry>
+ <term><literal>DYNAMIC RESULT SETS <replaceable
class="parameter">dynamic_result_sets</replaceable></literal></term>
+
+ <listitem>
+ <para>
+ Specifies how many dynamic result sets the procedure returns (see
+ <literal><link linkend="sql-declare">DECLARE</link> WITH
+ RETURN</literal>). The default is 0. If a procedure returns more
+ result sets than declared, a warning is raised.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry>
<term><literal>TRANSFORM { FOR TYPE <replaceable
class="parameter">type_name</replaceable> } [, ... ] }</literal></term>
diff --git a/doc/src/sgml/ref/declare.sgml b/doc/src/sgml/ref/declare.sgml
index 5712825314..206ed760d9 100644
--- a/doc/src/sgml/ref/declare.sgml
+++ b/doc/src/sgml/ref/declare.sgml
@@ -32,7 +32,8 @@
<refsynopsisdiv>
<synopsis>
DECLARE <replaceable class="parameter">name</replaceable> [ BINARY ] [
ASENSITIVE | INSENSITIVE ] [ [ NO ] SCROLL ]
- CURSOR [ { WITH | WITHOUT } HOLD ] FOR <replaceable
class="parameter">query</replaceable>
+ CURSOR [ { WITH | WITHOUT } HOLD ] [ { WITH | WITHOUT } RETURN ]
+ FOR <replaceable class="parameter">query</replaceable>
</synopsis>
</refsynopsisdiv>
@@ -138,6 +139,22 @@ <title>Parameters</title>
</listitem>
</varlistentry>
+ <varlistentry>
+ <term><literal>WITH RETURN</literal></term>
+ <term><literal>WITHOUT RETURN</literal></term>
+ <listitem>
+ <para>
+ This option is only valid for cursors defined inside a procedure.
+ <literal>WITH RETURN</literal> specifies that the cursor's result rows
+ will be provided as a result set of the procedure invocation. To
+ accomplish that, the cursor must be left open at the end of the
+ procedure. If multiple <literal>WITH RETURN</literal> cursors are
+ declared, then their results will be returned in the order they were
+ created. <literal>WITHOUT RETURN</literal> is the default.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry>
<term><replaceable class="parameter">query</replaceable></term>
<listitem>
@@ -339,6 +356,21 @@ <title>Examples</title>
See <xref linkend="sql-fetch"/> for more
examples of cursor usage.
</para>
+
+ <para>
+ This example shows how to return multiple result sets from a procedure:
+<programlisting>
+CREATE PROCEDURE test()
+LANGUAGE SQL
+AS $$
+DECLARE a CURSOR WITH RETURN FOR SELECT * FROM tbl1;
+DECLARE b CURSOR WITH RETURN FOR SELECT * FROM tbl2;
+$$;
+
+CALL test();
+</programlisting>
+ The results of the two cursors will be returned in order from this call.
+ </para>
</refsect1>
<refsect1>
diff --git a/src/backend/catalog/information_schema.sql
b/src/backend/catalog/information_schema.sql
index 0555e9bc03..871a27b84b 100644
--- a/src/backend/catalog/information_schema.sql
+++ b/src/backend/catalog/information_schema.sql
@@ -1593,7 +1593,7 @@ CREATE VIEW routines AS
CASE WHEN p.proisstrict THEN 'YES' ELSE 'NO' END END AS
yes_or_no) AS is_null_call,
CAST(null AS character_data) AS sql_path,
CAST('YES' AS yes_or_no) AS schema_level_routine,
- CAST(0 AS cardinal_number) AS max_dynamic_result_sets,
+ CAST(p.prodynres AS cardinal_number) AS max_dynamic_result_sets,
CAST(null AS yes_or_no) AS is_user_defined_cast,
CAST(null AS yes_or_no) AS is_implicitly_invocable,
CAST(CASE WHEN p.prosecdef THEN 'DEFINER' ELSE 'INVOKER' END AS
character_data) AS security_type,
diff --git a/src/backend/catalog/pg_aggregate.c
b/src/backend/catalog/pg_aggregate.c
index ebc4454743..a633bb7501 100644
--- a/src/backend/catalog/pg_aggregate.c
+++ b/src/backend/catalog/pg_aggregate.c
@@ -640,7 +640,8 @@ AggregateCreate(const char *aggName,
PointerGetDatum(NULL),
/* proconfig */
InvalidOid, /* no
prosupport */
1, /* procost */
- 0); /* prorows */
+ 0, /* prorows */
+ 0); /* prodynres */
procOid = myself.objectId;
/*
diff --git a/src/backend/catalog/pg_proc.c b/src/backend/catalog/pg_proc.c
index 14d552fe2d..620fb80a9c 100644
--- a/src/backend/catalog/pg_proc.c
+++ b/src/backend/catalog/pg_proc.c
@@ -95,7 +95,8 @@ ProcedureCreate(const char *procedureName,
Datum proconfig,
Oid prosupport,
float4 procost,
- float4 prorows)
+ float4 prorows,
+ int dynres)
{
Oid retval;
int parameterCount;
@@ -314,6 +315,7 @@ ProcedureCreate(const char *procedureName,
values[Anum_pg_proc_proretset - 1] = BoolGetDatum(returnsSet);
values[Anum_pg_proc_provolatile - 1] = CharGetDatum(volatility);
values[Anum_pg_proc_proparallel - 1] = CharGetDatum(parallel);
+ values[Anum_pg_proc_prodynres - 1] = Int32GetDatum(dynres);
values[Anum_pg_proc_pronargs - 1] = UInt16GetDatum(parameterCount);
values[Anum_pg_proc_pronargdefaults - 1] =
UInt16GetDatum(list_length(parameterDefaults));
values[Anum_pg_proc_prorettype - 1] = ObjectIdGetDatum(returnType);
diff --git a/src/backend/catalog/sql_features.txt
b/src/backend/catalog/sql_features.txt
index 3766762ae3..c12fc07cd0 100644
--- a/src/backend/catalog/sql_features.txt
+++ b/src/backend/catalog/sql_features.txt
@@ -486,7 +486,7 @@ T433 Multiargument GROUPING function
YES
T434 GROUP BY DISTINCT YES
T441 ABS and MOD functions YES
T461 Symmetric BETWEEN predicate YES
-T471 Result sets return value NO
+T471 Result sets return value NO partially
supported
T472 DESCRIBE CURSOR NO
T491 LATERAL derived table YES
T495 Combined data change and retrieval NO
different syntax
diff --git a/src/backend/commands/functioncmds.c
b/src/backend/commands/functioncmds.c
index 69f66dfe7d..5200a92fa9 100644
--- a/src/backend/commands/functioncmds.c
+++ b/src/backend/commands/functioncmds.c
@@ -72,6 +72,7 @@
#include "utils/guc.h"
#include "utils/lsyscache.h"
#include "utils/memutils.h"
+#include "utils/portal.h"
#include "utils/rel.h"
#include "utils/snapmgr.h"
#include "utils/syscache.h"
@@ -513,7 +514,8 @@ compute_common_attribute(ParseState *pstate,
DefElem **cost_item,
DefElem **rows_item,
DefElem **support_item,
- DefElem **parallel_item)
+ DefElem **parallel_item,
+ DefElem **dynres_item)
{
if (strcmp(defel->defname, "volatility") == 0)
{
@@ -589,12 +591,28 @@ compute_common_attribute(ParseState *pstate,
*parallel_item = defel;
}
+ else if (strcmp(defel->defname, "dynamic_result_sets") == 0)
+ {
+ if (!is_procedure)
+ goto function_error;
+ if (*dynres_item)
+ errorConflictingDefElem(defel, pstate);
+
+ *dynres_item = defel;
+ }
else
return false;
/* Recognized an option */
return true;
+function_error:
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
+ errmsg("invalid attribute in function definition"),
+ parser_errposition(pstate, defel->location)));
+ return false;
+
procedure_error:
ereport(ERROR,
(errcode(ERRCODE_INVALID_FUNCTION_DEFINITION),
@@ -731,7 +749,8 @@ compute_function_attributes(ParseState *pstate,
float4 *procost,
float4 *prorows,
Oid *prosupport,
- char *parallel_p)
+ char *parallel_p,
+ int *dynres_p)
{
ListCell *option;
DefElem *as_item = NULL;
@@ -747,6 +766,7 @@ compute_function_attributes(ParseState *pstate,
DefElem *rows_item = NULL;
DefElem *support_item = NULL;
DefElem *parallel_item = NULL;
+ DefElem *dynres_item = NULL;
foreach(option, options)
{
@@ -792,7 +812,8 @@ compute_function_attributes(ParseState *pstate,
&cost_item,
&rows_item,
&support_item,
-
¶llel_item))
+
¶llel_item,
+
&dynres_item))
{
/* recognized common option */
continue;
@@ -840,6 +861,11 @@ compute_function_attributes(ParseState *pstate,
*prosupport = interpret_func_support(support_item);
if (parallel_item)
*parallel_p = interpret_func_parallel(parallel_item);
+ if (dynres_item)
+ {
+ *dynres_p = intVal(dynres_item->arg);
+ Assert(*dynres_p >= 0); /* enforced by parser */
+ }
}
@@ -1051,6 +1077,7 @@ CreateFunction(ParseState *pstate, CreateFunctionStmt
*stmt)
Form_pg_language languageStruct;
List *as_clause;
char parallel;
+ int dynres;
/* Convert list of names to a name and namespace */
namespaceId = QualifiedNameGetCreationNamespace(stmt->funcname,
@@ -1075,6 +1102,7 @@ CreateFunction(ParseState *pstate, CreateFunctionStmt
*stmt)
prorows = -1; /* indicates not set */
prosupport = InvalidOid;
parallel = PROPARALLEL_UNSAFE;
+ dynres = 0;
/* Extract non-default attributes from stmt->options list */
compute_function_attributes(pstate,
@@ -1084,7 +1112,7 @@ CreateFunction(ParseState *pstate, CreateFunctionStmt
*stmt)
&isWindowFunc,
&volatility,
&isStrict,
&security, &isLeakProof,
&proconfig,
&procost, &prorows,
- &prosupport,
¶llel);
+ &prosupport,
¶llel, &dynres);
if (!language)
{
@@ -1285,7 +1313,8 @@ CreateFunction(ParseState *pstate, CreateFunctionStmt
*stmt)
PointerGetDatum(proconfig),
prosupport,
procost,
- prorows);
+ prorows,
+ dynres);
}
/*
@@ -1362,6 +1391,7 @@ AlterFunction(ParseState *pstate, AlterFunctionStmt *stmt)
DefElem *rows_item = NULL;
DefElem *support_item = NULL;
DefElem *parallel_item = NULL;
+ DefElem *dynres_item = NULL;
ObjectAddress address;
rel = table_open(ProcedureRelationId, RowExclusiveLock);
@@ -1405,7 +1435,8 @@ AlterFunction(ParseState *pstate, AlterFunctionStmt *stmt)
&cost_item,
&rows_item,
&support_item,
-
¶llel_item) == false)
+
¶llel_item,
+
&dynres_item) == false)
elog(ERROR, "option \"%s\" not recognized",
defel->defname);
}
@@ -1467,6 +1498,8 @@ AlterFunction(ParseState *pstate, AlterFunctionStmt *stmt)
}
if (parallel_item)
procForm->proparallel = interpret_func_parallel(parallel_item);
+ if (dynres_item)
+ procForm->prodynres = intVal(dynres_item->arg);
if (set_items)
{
Datum datum;
@@ -2144,6 +2177,17 @@ ExecuteDoStmt(ParseState *pstate, DoStmt *stmt, bool
atomic)
OidFunctionCall1(laninline, PointerGetDatum(codeblock));
}
+static List *procedure_stack;
+
+Oid
+CurrentProcedure(void)
+{
+ if (!procedure_stack)
+ return InvalidOid;
+ else
+ return llast_oid(procedure_stack);
+}
+
/*
* Execute CALL statement
*
@@ -2183,6 +2227,7 @@ ExecuteCallStmt(CallStmt *stmt, ParamListInfo params,
bool atomic, DestReceiver
AclResult aclresult;
FmgrInfo flinfo;
CallContext *callcontext;
+ int prodynres;
EState *estate;
ExprContext *econtext;
HeapTuple tp;
@@ -2223,6 +2268,8 @@ ExecuteCallStmt(CallStmt *stmt, ParamListInfo params,
bool atomic, DestReceiver
if (((Form_pg_proc) GETSTRUCT(tp))->prosecdef)
callcontext->atomic = true;
+ prodynres = ((Form_pg_proc) GETSTRUCT(tp))->prodynres;
+
ReleaseSysCache(tp);
/* safety check; see ExecInitFunc() */
@@ -2283,7 +2330,18 @@ ExecuteCallStmt(CallStmt *stmt, ParamListInfo params,
bool atomic, DestReceiver
/* Here we actually call the procedure */
pgstat_init_function_usage(fcinfo, &fcusage);
- retval = FunctionCallInvoke(fcinfo);
+
+ procedure_stack = lappend_oid(procedure_stack, fexpr->funcid);
+ PG_TRY();
+ {
+ retval = FunctionCallInvoke(fcinfo);
+ }
+ PG_FINALLY();
+ {
+ procedure_stack = list_delete_last(procedure_stack);
+ }
+ PG_END_TRY();
+
pgstat_end_function_usage(&fcusage, true);
/* Handle the procedure's outputs */
@@ -2344,6 +2402,13 @@ ExecuteCallStmt(CallStmt *stmt, ParamListInfo params,
bool atomic, DestReceiver
fexpr->funcresulttype);
FreeExecutorState(estate);
+
+ CloseOtherReturnableCursors(fexpr->funcid);
+
+ if (list_length(GetReturnableCursors()) > prodynres)
+ ereport(WARNING,
+
errcode(ERRCODE_WARNING_ATTEMPT_TO_RETURN_TOO_MANY_RESULT_SETS),
+ errmsg("attempt to return too many result
sets"));
}
/*
diff --git a/src/backend/commands/portalcmds.c
b/src/backend/commands/portalcmds.c
index 8a3cf98cce..e73f7bfb22 100644
--- a/src/backend/commands/portalcmds.c
+++ b/src/backend/commands/portalcmds.c
@@ -24,6 +24,7 @@
#include <limits.h>
#include "access/xact.h"
+#include "commands/defrem.h"
#include "commands/portalcmds.h"
#include "executor/executor.h"
#include "executor/tstoreReceiver.h"
@@ -140,6 +141,28 @@ PerformCursorOpen(ParseState *pstate, DeclareCursorStmt
*cstmt, ParamListInfo pa
portal->cursorOptions |= CURSOR_OPT_NO_SCROLL;
}
+ /*
+ * For returnable cursors, remember the currently active procedure, as
+ * well as the command ID, so we can sort by creation order later. If
+ * there is no procedure active, the cursor is marked as WITHOUT RETURN.
+ * (This is not an error, per SQL standard, subclause "Effect of
opening a
+ * cursor".)
+ */
+ if (portal->cursorOptions & CURSOR_OPT_RETURN)
+ {
+ Oid procId = CurrentProcedure();
+
+ if (procId)
+ {
+ portal->procId = procId;
+ portal->createCid = GetCurrentCommandId(true);
+ }
+ else
+ {
+ portal->cursorOptions &= ~CURSOR_OPT_RETURN;
+ }
+ }
+
/*
* Start execution, inserting parameters if any.
*/
diff --git a/src/backend/commands/typecmds.c b/src/backend/commands/typecmds.c
index 04bddaef81..1e40fcedd3 100644
--- a/src/backend/commands/typecmds.c
+++ b/src/backend/commands/typecmds.c
@@ -1777,7 +1777,8 @@ makeRangeConstructors(const char *name, Oid namespace,
PointerGetDatum(NULL), /* proconfig */
InvalidOid,
/* prosupport */
1.0, /*
procost */
- 0.0); /*
prorows */
+ 0.0, /*
prorows */
+ 0); /*
prodynres */
/*
* Make the constructors internally-dependent on the range type
so
@@ -1842,7 +1843,8 @@ makeMultirangeConstructors(const char *name, Oid
namespace,
PointerGetDatum(NULL),
/* proconfig */
InvalidOid, /*
prosupport */
1.0, /* procost */
- 0.0); /* prorows */
+ 0.0, /* prorows */
+ 0); /* prodynres */
/*
* Make the constructor internally-dependent on the multirange type so
@@ -1886,7 +1888,8 @@ makeMultirangeConstructors(const char *name, Oid
namespace,
PointerGetDatum(NULL),
/* proconfig */
InvalidOid, /*
prosupport */
1.0, /* procost */
- 0.0); /* prorows */
+ 0.0, /* prorows */
+ 0); /* prodynres */
/* ditto */
recordDependencyOn(&myself, &referenced, DEPENDENCY_INTERNAL);
pfree(argtypes);
@@ -1924,7 +1927,8 @@ makeMultirangeConstructors(const char *name, Oid
namespace,
PointerGetDatum(NULL),
/* proconfig */
InvalidOid, /*
prosupport */
1.0, /* procost */
- 0.0); /* prorows */
+ 0.0, /* prorows */
+ 0); /* prodynres */
/* ditto */
recordDependencyOn(&myself, &referenced, DEPENDENCY_INTERNAL);
pfree(argtypes);
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index a0138382a1..8312fbf2c6 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -688,7 +688,7 @@ static Node *makeRecursiveViewSelect(char *relname, List
*aliases, Node *query);
DATA_P DATABASE DAY_P DEALLOCATE DEC DECIMAL_P DECLARE DEFAULT DEFAULTS
DEFERRABLE DEFERRED DEFINER DELETE_P DELIMITER DELIMITERS DEPENDS DEPTH
DESC
DETACH DICTIONARY DISABLE_P DISCARD DISTINCT DO DOCUMENT_P DOMAIN_P
- DOUBLE_P DROP
+ DOUBLE_P DROP DYNAMIC
EACH ELSE ENABLE_P ENCODING ENCRYPTED END_P ENUM_P ESCAPE EVENT EXCEPT
EXCLUDE EXCLUDING EXCLUSIVE EXECUTE EXISTS EXPLAIN EXPRESSION
@@ -735,7 +735,7 @@ static Node *makeRecursiveViewSelect(char *relname, List
*aliases, Node *query);
RANGE READ REAL REASSIGN RECHECK RECURSIVE REF_P REFERENCES REFERENCING
REFRESH REINDEX RELATIVE_P RELEASE RENAME REPEATABLE REPLACE REPLICA
- RESET RESTART RESTRICT RETURN RETURNING RETURNS REVOKE RIGHT ROLE
ROLLBACK ROLLUP
+ RESET RESTART RESTRICT RESULT RETURN RETURNING RETURNS REVOKE RIGHT
ROLE ROLLBACK ROLLUP
ROUTINE ROUTINES ROW ROWS RULE
SAVEPOINT SCHEMA SCHEMAS SCROLL SEARCH SECOND_P SECURITY SELECT
SEQUENCE SEQUENCES
@@ -8532,6 +8532,10 @@ common_func_opt_item:
{
$$ = makeDefElem("parallel", (Node *)
makeString($2), @1);
}
+ | DYNAMIC RESULT SETS Iconst
+ {
+ $$ = makeDefElem("dynamic_result_sets",
(Node *)makeInteger($4), @1);
+ }
;
createfunc_opt_item:
@@ -12421,6 +12425,12 @@ cursor_options: /*EMPTY*/
{ $$ = 0; }
opt_hold: /* EMPTY */ { $$ = 0; }
| WITH HOLD
{ $$ = CURSOR_OPT_HOLD; }
| WITHOUT HOLD { $$ =
0; }
+ | WITH HOLD WITH RETURN { $$ =
CURSOR_OPT_HOLD | CURSOR_OPT_RETURN; }
+ | WITHOUT HOLD WITH RETURN { $$ =
CURSOR_OPT_RETURN; }
+ | WITH HOLD WITHOUT RETURN { $$ =
CURSOR_OPT_HOLD; }
+ | WITHOUT HOLD WITHOUT RETURN { $$ = 0; }
+ | WITH RETURN { $$ =
CURSOR_OPT_RETURN; }
+ | WITHOUT RETURN { $$ =
0; }
;
/*****************************************************************************
@@ -16787,6 +16797,7 @@ unreserved_keyword:
| DOMAIN_P
| DOUBLE_P
| DROP
+ | DYNAMIC
| EACH
| ENABLE_P
| ENCODING
@@ -16932,6 +16943,7 @@ unreserved_keyword:
| RESET
| RESTART
| RESTRICT
+ | RESULT
| RETURN
| RETURNS
| REVOKE
@@ -17332,6 +17344,7 @@ bare_label_keyword:
| DOMAIN_P
| DOUBLE_P
| DROP
+ | DYNAMIC
| EACH
| ELSE
| ENABLE_P
@@ -17519,6 +17532,7 @@ bare_label_keyword:
| RESET
| RESTART
| RESTRICT
+ | RESULT
| RETURN
| RETURNS
| REVOKE
diff --git a/src/backend/tcop/postgres.c b/src/backend/tcop/postgres.c
index cab709b07b..98ac9aa012 100644
--- a/src/backend/tcop/postgres.c
+++ b/src/backend/tcop/postgres.c
@@ -32,6 +32,7 @@
#include "access/xact.h"
#include "catalog/pg_type.h"
#include "commands/async.h"
+#include "commands/defrem.h"
#include "commands/prepare.h"
#include "common/pg_prng.h"
#include "jit/jit.h"
@@ -1073,6 +1074,7 @@ exec_simple_query(const char *query_string)
int16 format;
const char *cmdtagname;
size_t cmdtaglen;
+ ListCell *lc;
pgstat_report_query_id(0, true);
@@ -1235,7 +1237,7 @@ exec_simple_query(const char *query_string)
MemoryContextSwitchTo(oldcontext);
/*
- * Run the portal to completion, and then drop it (and the
receiver).
+ * Run the portal to completion, and then drop it.
*/
(void) PortalRun(portal,
FETCH_ALL,
@@ -1245,10 +1247,34 @@ exec_simple_query(const char *query_string)
receiver,
&qc);
- receiver->rDestroy(receiver);
-
PortalDrop(portal, false);
+ /*
+ * Run portals for dynamic result sets.
+ */
+ foreach (lc, GetReturnableCursors())
+ {
+ Portal dynportal = lfirst(lc);
+
+ if (dest == DestRemote)
+ SetRemoteDestReceiverParams(receiver,
dynportal);
+
+ PortalRun(dynportal,
+ FETCH_ALL,
+ true,
+ true,
+ receiver,
+ receiver,
+ NULL);
+
+ PortalDrop(dynportal, false);
+ }
+
+ /*
+ * Drop the receiver.
+ */
+ receiver->rDestroy(receiver);
+
if (lnext(parsetree_list, parsetree_item) == NULL)
{
/*
@@ -2200,6 +2226,11 @@ exec_execute_message(const char *portal_name, long
max_rows)
receiver,
&qc);
+ if (GetReturnableCursors())
+ ereport(ERROR,
+ errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("dynamic result sets are not yet
supported in extended query protocol"));
+
receiver->rDestroy(receiver);
/* Done executing; remove the params error callback */
diff --git a/src/backend/utils/errcodes.txt b/src/backend/utils/errcodes.txt
index 3d244af130..9b94a5fa92 100644
--- a/src/backend/utils/errcodes.txt
+++ b/src/backend/utils/errcodes.txt
@@ -83,6 +83,7 @@ Section: Class 01 - Warning
# do not use this class for failure conditions
01000 W ERRCODE_WARNING
warning
0100C W ERRCODE_WARNING_DYNAMIC_RESULT_SETS_RETURNED
dynamic_result_sets_returned
+0100E W ERRCODE_WARNING_ATTEMPT_TO_RETURN_TOO_MANY_RESULT_SETS
attempt_to_return_too_many_result_sets
01008 W ERRCODE_WARNING_IMPLICIT_ZERO_BIT_PADDING
implicit_zero_bit_padding
01003 W ERRCODE_WARNING_NULL_VALUE_ELIMINATED_IN_SET_FUNCTION
null_value_eliminated_in_set_function
01007 W ERRCODE_WARNING_PRIVILEGE_NOT_GRANTED
privilege_not_granted
diff --git a/src/backend/utils/mmgr/portalmem.c
b/src/backend/utils/mmgr/portalmem.c
index 06dfa85f04..f29a6eabf8 100644
--- a/src/backend/utils/mmgr/portalmem.c
+++ b/src/backend/utils/mmgr/portalmem.c
@@ -1289,3 +1289,51 @@ ForgetPortalSnapshots(void)
elog(ERROR, "portal snapshots (%d) did not account for all
active snapshots (%d)",
numPortalSnaps, numActiveSnaps);
}
+
+static int
+cmp_portals_by_creation(const ListCell *a, const ListCell *b)
+{
+ Portal pa = lfirst(a);
+ Portal pb = lfirst(b);
+
+ return pa->createCid - pb->createCid;
+}
+
+List *
+GetReturnableCursors(void)
+{
+ List *ret = NIL;
+ HASH_SEQ_STATUS status;
+ PortalHashEnt *hentry;
+
+ hash_seq_init(&status, PortalHashTable);
+
+ while ((hentry = (PortalHashEnt *) hash_seq_search(&status)) != NULL)
+ {
+ Portal portal = hentry->portal;
+
+ if (portal->cursorOptions & CURSOR_OPT_RETURN)
+ ret = lappend(ret, portal);
+ }
+
+ list_sort(ret, cmp_portals_by_creation);
+
+ return ret;
+}
+
+void
+CloseOtherReturnableCursors(Oid procid)
+{
+ HASH_SEQ_STATUS status;
+ PortalHashEnt *hentry;
+
+ hash_seq_init(&status, PortalHashTable);
+
+ while ((hentry = (PortalHashEnt *) hash_seq_search(&status)) != NULL)
+ {
+ Portal portal = hentry->portal;
+
+ if (portal->cursorOptions & CURSOR_OPT_RETURN && portal->procId
!= procid)
+ PortalDrop(portal, false);
+ }
+}
diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c
index 527c7651ab..659c5da25a 100644
--- a/src/bin/pg_dump/pg_dump.c
+++ b/src/bin/pg_dump/pg_dump.c
@@ -11647,6 +11647,7 @@ dumpFunc(Archive *fout, const FuncInfo *finfo)
char *prorows;
char *prosupport;
char *proparallel;
+ int prodynres;
char *lanname;
char **configitems = NULL;
int nconfigitems = 0;
@@ -11714,10 +11715,17 @@ dumpFunc(Archive *fout, const FuncInfo *finfo)
if (fout->remoteVersion >= 140000)
appendPQExpBufferStr(query,
-
"pg_get_function_sqlbody(p.oid) AS prosqlbody\n");
+
"pg_get_function_sqlbody(p.oid) AS prosqlbody,\n");
else
appendPQExpBufferStr(query,
- "NULL AS
prosqlbody\n");
+ "NULL AS
prosqlbody,\n");
+
+ if (fout->remoteVersion >= 160000)
+ appendPQExpBufferStr(query,
+ "prodynres\n");
+ else
+ appendPQExpBufferStr(query,
+ "0 AS
prodynres\n");
appendPQExpBufferStr(query,
"FROM
pg_catalog.pg_proc p, pg_catalog.pg_language l\n"
@@ -11762,6 +11770,7 @@ dumpFunc(Archive *fout, const FuncInfo *finfo)
prorows = PQgetvalue(res, 0, PQfnumber(res, "prorows"));
prosupport = PQgetvalue(res, 0, PQfnumber(res, "prosupport"));
proparallel = PQgetvalue(res, 0, PQfnumber(res, "proparallel"));
+ prodynres = atoi(PQgetvalue(res, 0, PQfnumber(res, "prodynres")));
lanname = PQgetvalue(res, 0, PQfnumber(res, "lanname"));
/*
@@ -11880,6 +11889,9 @@ dumpFunc(Archive *fout, const FuncInfo *finfo)
if (proisstrict[0] == 't')
appendPQExpBufferStr(q, " STRICT");
+ if (prodynres > 0)
+ appendPQExpBuffer(q, " DYNAMIC RESULT SETS %d", prodynres);
+
if (prosecdef[0] == 't')
appendPQExpBufferStr(q, " SECURITY DEFINER");
diff --git a/src/include/catalog/pg_proc.h b/src/include/catalog/pg_proc.h
index e7abe0b497..f4ef8f0ece 100644
--- a/src/include/catalog/pg_proc.h
+++ b/src/include/catalog/pg_proc.h
@@ -76,6 +76,9 @@ CATALOG(pg_proc,1255,ProcedureRelationId) BKI_BOOTSTRAP
BKI_ROWTYPE_OID(81,Proce
/* see PROPARALLEL_ categories below */
char proparallel BKI_DEFAULT(s);
+ /* maximum number of dynamic result sets */
+ int32 prodynres BKI_DEFAULT(0);
+
/* number of arguments */
/* Note: need not be given in pg_proc.dat; genbki.pl will compute it */
int16 pronargs;
@@ -211,7 +214,8 @@ extern ObjectAddress ProcedureCreate(const char
*procedureName,
Datum
proconfig,
Oid
prosupport,
float4
procost,
- float4
prorows);
+ float4
prorows,
+ int
dynres);
extern bool function_parse_error_transpose(const char *prosrc);
diff --git a/src/include/commands/defrem.h b/src/include/commands/defrem.h
index 4f7f87fc62..fcfe8df78e 100644
--- a/src/include/commands/defrem.h
+++ b/src/include/commands/defrem.h
@@ -57,6 +57,7 @@ extern ObjectAddress CreateTransform(CreateTransformStmt
*stmt);
extern void IsThereFunctionInNamespace(const char *proname, int pronargs,
oidvector *proargtypes, Oid nspOid);
extern void ExecuteDoStmt(ParseState *pstate, DoStmt *stmt, bool atomic);
+extern Oid CurrentProcedure(void);
extern void ExecuteCallStmt(CallStmt *stmt, ParamListInfo params, bool atomic,
DestReceiver *dest);
extern TupleDesc CallStmtResultDesc(CallStmt *stmt);
extern Oid get_transform_oid(Oid type_id, Oid lang_id, bool missing_ok);
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index f7d7f10f7d..acae7da708 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -3010,6 +3010,7 @@ typedef struct SecLabelStmt
#define CURSOR_OPT_INSENSITIVE 0x0008 /* INSENSITIVE */
#define CURSOR_OPT_ASENSITIVE 0x0010 /* ASENSITIVE */
#define CURSOR_OPT_HOLD 0x0020 /* WITH HOLD */
+#define CURSOR_OPT_RETURN 0x0040 /* WITH RETURN */
/* these planner-control flags do not correspond to any SQL grammar: */
#define CURSOR_OPT_FAST_PLAN 0x0100 /* prefer fast-start plan */
#define CURSOR_OPT_GENERIC_PLAN 0x0200 /* force use of generic plan */
diff --git a/src/include/parser/kwlist.h b/src/include/parser/kwlist.h
index bb36213e6f..60457d21f7 100644
--- a/src/include/parser/kwlist.h
+++ b/src/include/parser/kwlist.h
@@ -144,6 +144,7 @@ PG_KEYWORD("document", DOCUMENT_P, UNRESERVED_KEYWORD,
BARE_LABEL)
PG_KEYWORD("domain", DOMAIN_P, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("double", DOUBLE_P, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("drop", DROP, UNRESERVED_KEYWORD, BARE_LABEL)
+PG_KEYWORD("dynamic", DYNAMIC, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("each", EACH, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("else", ELSE, RESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("enable", ENABLE_P, UNRESERVED_KEYWORD, BARE_LABEL)
@@ -353,6 +354,7 @@ PG_KEYWORD("replica", REPLICA, UNRESERVED_KEYWORD,
BARE_LABEL)
PG_KEYWORD("reset", RESET, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("restart", RESTART, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("restrict", RESTRICT, UNRESERVED_KEYWORD, BARE_LABEL)
+PG_KEYWORD("result", RESULT, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("return", RETURN, UNRESERVED_KEYWORD, BARE_LABEL)
PG_KEYWORD("returning", RETURNING, RESERVED_KEYWORD, AS_LABEL)
PG_KEYWORD("returns", RETURNS, UNRESERVED_KEYWORD, BARE_LABEL)
diff --git a/src/include/utils/portal.h b/src/include/utils/portal.h
index aa08b1e0fc..6f04362dfe 100644
--- a/src/include/utils/portal.h
+++ b/src/include/utils/portal.h
@@ -132,6 +132,16 @@ typedef struct PortalData
SubTransactionId activeSubid; /* the last subxact with activity */
int createLevel; /* creating subxact's nesting
level */
+ /*
+ * Procedure that created this portal. Used for returnable cursors.
+ */
+ Oid procId;
+ /*
+ * Command ID where the portal was created. Used for sorting returnable
+ * cursors into creation order.
+ */
+ CommandId createCid;
+
/* The query or queries the portal will execute */
const char *sourceText; /* text of query (as of 8.4, never
NULL) */
CommandTag commandTag; /* command tag for original
query */
@@ -248,5 +258,7 @@ extern void PortalHashTableDeleteAll(void);
extern bool ThereAreNoReadyPortals(void);
extern void HoldPinnedPortals(void);
extern void ForgetPortalSnapshots(void);
+extern List *GetReturnableCursors(void);
+extern void CloseOtherReturnableCursors(Oid procid);
#endif /* PORTAL_H */
diff --git a/src/pl/plpgsql/src/expected/plpgsql_call.out
b/src/pl/plpgsql/src/expected/plpgsql_call.out
index 1ec6182a8d..1c8872a754 100644
--- a/src/pl/plpgsql/src/expected/plpgsql_call.out
+++ b/src/pl/plpgsql/src/expected/plpgsql_call.out
@@ -466,3 +466,81 @@ BEGIN
END;
$$;
NOTICE: <NULL>
+-- dynamic result sets
+CREATE TABLE cp_test2 (a int);
+INSERT INTO cp_test2 VALUES (1), (2), (3);
+CREATE TABLE cp_test3 (x text, y text);
+INSERT INTO cp_test3 VALUES ('abc', 'def'), ('foo', 'bar');
+CREATE PROCEDURE pdrstest1(x int)
+LANGUAGE plpgsql
+DYNAMIC RESULT SETS 2
+AS $$
+DECLARE
+ c1 CURSOR WITH RETURN (y int) FOR SELECT a * y AS ay FROM cp_test2;
+ c2 CURSOR WITH RETURN FOR SELECT * FROM cp_test3;
+BEGIN
+ OPEN c1(x);
+ IF x > 1 THEN
+ OPEN c2;
+ END IF;
+END;
+$$;
+CALL pdrstest1(1);
+ ay
+----
+ 1
+ 2
+ 3
+(3 rows)
+
+CALL pdrstest1(2);
+ ay
+----
+ 2
+ 4
+ 6
+(3 rows)
+
+ x | y
+-----+-----
+ abc | def
+ foo | bar
+(2 rows)
+
+CREATE PROCEDURE pdrstest2(x int)
+LANGUAGE plpgsql
+DYNAMIC RESULT SETS 2
+AS $$
+DECLARE
+ c1 refcursor;
+ c2 refcursor;
+BEGIN
+ OPEN c1 WITH RETURN FOR SELECT a * x AS ax FROM cp_test2;
+ IF x > 1 THEN
+ OPEN c2 SCROLL WITH RETURN FOR SELECT * FROM cp_test3;
+ END IF;
+END;
+$$;
+CALL pdrstest2(1);
+ ax
+----
+ 1
+ 2
+ 3
+(3 rows)
+
+CALL pdrstest2(2);
+ ax
+----
+ 2
+ 4
+ 6
+(3 rows)
+
+ x | y
+-----+-----
+ abc | def
+ foo | bar
+(2 rows)
+
+DROP TABLE cp_test2, cp_test3;
diff --git a/src/pl/plpgsql/src/pl_exec.c b/src/pl/plpgsql/src/pl_exec.c
index ffd6d2e3bc..ea11144f6d 100644
--- a/src/pl/plpgsql/src/pl_exec.c
+++ b/src/pl/plpgsql/src/pl_exec.c
@@ -4776,6 +4776,12 @@ exec_stmt_open(PLpgSQL_execstate *estate,
PLpgSQL_stmt_open *stmt)
elog(ERROR, "could not open cursor: %s",
SPI_result_code_string(SPI_result));
+ if (portal->cursorOptions & CURSOR_OPT_RETURN)
+ {
+ portal->procId = estate->func->fn_oid;
+ portal->createCid = GetCurrentCommandId(true);
+ }
+
/*
* If cursor variable was NULL, store the generated portal name in it,
* after verifying it's okay to assign to.
diff --git a/src/pl/plpgsql/src/pl_gram.y b/src/pl/plpgsql/src/pl_gram.y
index edeb72c380..bff1557005 100644
--- a/src/pl/plpgsql/src/pl_gram.y
+++ b/src/pl/plpgsql/src/pl_gram.y
@@ -212,7 +212,7 @@ static void
check_raise_parameters(PLpgSQL_stmt_raise *stmt);
%type <datum> getdiag_target
%type <ival> getdiag_item
-%type <ival> opt_scrollable
+%type <ival> opt_scrollable opt_with_return
%type <fetch> opt_fetch_direction
%type <ival> opt_transaction_chain
@@ -352,6 +352,8 @@ static void
check_raise_parameters(PLpgSQL_stmt_raise *stmt);
%token <keyword> K_WARNING
%token <keyword> K_WHEN
%token <keyword> K_WHILE
+%token <keyword> K_WITH
+%token <keyword> K_WITHOUT
%%
@@ -529,7 +531,7 @@ decl_statement : decl_varname decl_const decl_datatype
decl_collate decl_notnull
plpgsql_ns_additem($4->itemtype,
$4->itemno, $1.name);
}
- | decl_varname opt_scrollable K_CURSOR
+ | decl_varname opt_scrollable K_CURSOR
opt_with_return
{ plpgsql_ns_push($1.name,
PLPGSQL_LABEL_OTHER); }
decl_cursor_args decl_is_for decl_cursor_query
{
@@ -546,12 +548,12 @@ decl_statement : decl_varname decl_const decl_datatype
decl_collate decl_notnull
NULL),
true);
- new->cursor_explicit_expr = $7;
- if ($5 == NULL)
+ new->cursor_explicit_expr = $8;
+ if ($6 == NULL)
new->cursor_explicit_argrow = -1;
else
-
new->cursor_explicit_argrow = $5->dno;
- new->cursor_options =
CURSOR_OPT_FAST_PLAN | $2;
+
new->cursor_explicit_argrow = $6->dno;
+ new->cursor_options =
CURSOR_OPT_FAST_PLAN | $2 | $4;
}
;
@@ -569,6 +571,20 @@ opt_scrollable :
}
;
+opt_with_return :
+ {
+ $$ = 0;
+ }
+ | K_WITH K_RETURN
+ {
+ $$ = CURSOR_OPT_RETURN;
+ }
+ | K_WITHOUT K_RETURN
+ {
+ $$ = 0;
+ }
+ ;
+
decl_cursor_query :
{
$$ = read_sql_stmt();
@@ -1976,6 +1992,10 @@ stmt_execsql : K_IMPORT
{
$$ = make_execsql_stmt(K_MERGE,
@1);
}
+ | K_WITH
+ {
+ $$ = make_execsql_stmt(K_WITH,
@1);
+ }
| T_WORD
{
int tok;
@@ -2098,6 +2118,30 @@ stmt_open : K_OPEN cursor_variable
tok = yylex();
}
+ /* same for
opt_with_return */
+ if (tok_is_keyword(tok,
&yylval,
+
K_WITH, "with"))
+ {
+ tok = yylex();
+ if
(tok_is_keyword(tok, &yylval,
+
K_RETURN, "return"))
+ {
+
new->cursor_options |= CURSOR_OPT_RETURN;
+ tok =
yylex();
+ }
+ }
+ else if
(tok_is_keyword(tok, &yylval,
+
K_WITHOUT, "without"))
+ {
+ tok = yylex();
+ if
(tok_is_keyword(tok, &yylval,
+
K_RETURN, "return"))
+ {
+
new->cursor_options |= 0;
+ tok =
yylex();
+ }
+ }
+
if (tok != K_FOR)
yyerror("syntax
error, expected \"FOR\"");
@@ -2552,6 +2596,8 @@ unreserved_keyword :
| K_USE_VARIABLE
| K_VARIABLE_CONFLICT
| K_WARNING
+ | K_WITH
+ | K_WITHOUT
;
%%
diff --git a/src/pl/plpgsql/src/pl_unreserved_kwlist.h
b/src/pl/plpgsql/src/pl_unreserved_kwlist.h
index 466bdc7a20..8a8f8ea47a 100644
--- a/src/pl/plpgsql/src/pl_unreserved_kwlist.h
+++ b/src/pl/plpgsql/src/pl_unreserved_kwlist.h
@@ -109,3 +109,5 @@ PG_KEYWORD("use_column", K_USE_COLUMN)
PG_KEYWORD("use_variable", K_USE_VARIABLE)
PG_KEYWORD("variable_conflict", K_VARIABLE_CONFLICT)
PG_KEYWORD("warning", K_WARNING)
+PG_KEYWORD("with", K_WITH)
+PG_KEYWORD("without", K_WITHOUT)
diff --git a/src/pl/plpgsql/src/sql/plpgsql_call.sql
b/src/pl/plpgsql/src/sql/plpgsql_call.sql
index 5028398348..9ace9d4e06 100644
--- a/src/pl/plpgsql/src/sql/plpgsql_call.sql
+++ b/src/pl/plpgsql/src/sql/plpgsql_call.sql
@@ -436,3 +436,49 @@ CREATE PROCEDURE p1(v_cnt int, v_Text inout text = NULL)
RAISE NOTICE '%', v_Text;
END;
$$;
+
+
+-- dynamic result sets
+
+CREATE TABLE cp_test2 (a int);
+INSERT INTO cp_test2 VALUES (1), (2), (3);
+CREATE TABLE cp_test3 (x text, y text);
+INSERT INTO cp_test3 VALUES ('abc', 'def'), ('foo', 'bar');
+
+CREATE PROCEDURE pdrstest1(x int)
+LANGUAGE plpgsql
+DYNAMIC RESULT SETS 2
+AS $$
+DECLARE
+ c1 CURSOR WITH RETURN (y int) FOR SELECT a * y AS ay FROM cp_test2;
+ c2 CURSOR WITH RETURN FOR SELECT * FROM cp_test3;
+BEGIN
+ OPEN c1(x);
+ IF x > 1 THEN
+ OPEN c2;
+ END IF;
+END;
+$$;
+
+CALL pdrstest1(1);
+CALL pdrstest1(2);
+
+CREATE PROCEDURE pdrstest2(x int)
+LANGUAGE plpgsql
+DYNAMIC RESULT SETS 2
+AS $$
+DECLARE
+ c1 refcursor;
+ c2 refcursor;
+BEGIN
+ OPEN c1 WITH RETURN FOR SELECT a * x AS ax FROM cp_test2;
+ IF x > 1 THEN
+ OPEN c2 SCROLL WITH RETURN FOR SELECT * FROM cp_test3;
+ END IF;
+END;
+$$;
+
+CALL pdrstest2(1);
+CALL pdrstest2(2);
+
+DROP TABLE cp_test2, cp_test3;
diff --git a/src/test/regress/expected/create_procedure.out
b/src/test/regress/expected/create_procedure.out
index f2a677fa55..8cc009d1b2 100644
--- a/src/test/regress/expected/create_procedure.out
+++ b/src/test/regress/expected/create_procedure.out
@@ -375,9 +375,107 @@ ALTER ROUTINE cp_testfunc1a RENAME TO cp_testfunc1;
ALTER ROUTINE ptest1(text) RENAME TO ptest1a;
ALTER ROUTINE ptest1a RENAME TO ptest1;
DROP ROUTINE cp_testfunc1(int);
+-- dynamic result sets
+CREATE TABLE cp_test2 (a int);
+INSERT INTO cp_test2 VALUES (1), (2), (3);
+CREATE TABLE cp_test3 (x text, y text);
+INSERT INTO cp_test3 VALUES ('abc', 'def'), ('foo', 'bar');
+CREATE PROCEDURE pdrstest1()
+LANGUAGE SQL
+DYNAMIC RESULT SETS 2
+AS $$
+DECLARE c1 CURSOR WITH RETURN FOR SELECT * FROM cp_test2;
+DECLARE c2 CURSOR WITH RETURN FOR SELECT * FROM cp_test3;
+$$;
+CALL pdrstest1();
+ a
+---
+ 1
+ 2
+ 3
+(3 rows)
+
+ x | y
+-----+-----
+ abc | def
+ foo | bar
+(2 rows)
+
+CALL pdrstest1() \bind \g
+ERROR: dynamic result sets are not yet supported in extended query protocol
+CREATE PROCEDURE pdrstest2()
+LANGUAGE SQL
+DYNAMIC RESULT SETS 1
+AS $$
+CALL pdrstest1();
+DECLARE c3 CURSOR WITH RETURN FOR SELECT * FROM cp_test2 WHERE a < 2;
+$$;
+CALL pdrstest2();
+ a
+---
+ 1
+(1 row)
+
+CALL pdrstest2() \bind \g
+ERROR: dynamic result sets are not yet supported in extended query protocol
+CREATE PROCEDURE pdrstest3(INOUT a text)
+LANGUAGE SQL
+DYNAMIC RESULT SETS 1
+AS $$
+DECLARE c4 CURSOR WITH RETURN FOR SELECT * FROM cp_test2;
+SELECT a || a;
+$$;
+CALL pdrstest3('x');
+ a
+----
+ xx
+(1 row)
+
+ a
+---
+ 1
+ 2
+ 3
+(3 rows)
+
+CALL pdrstest3($1) \bind 'y' \g
+ERROR: dynamic result sets are not yet supported in extended query protocol
+-- test the nested error handling
+CREATE TABLE cp_test_dummy (a int);
+CREATE PROCEDURE pdrstest4a()
+LANGUAGE SQL
+DYNAMIC RESULT SETS 1
+AS $$
+DECLARE c5a CURSOR WITH RETURN FOR SELECT * FROM cp_test_dummy;
+$$;
+CREATE PROCEDURE pdrstest4b()
+LANGUAGE SQL
+DYNAMIC RESULT SETS 1
+AS $$
+CALL pdrstest4a();
+$$;
+DROP TABLE cp_test_dummy;
+CALL pdrstest4b();
+ERROR: relation "cp_test_dummy" does not exist
+LINE 2: DECLARE c5a CURSOR WITH RETURN FOR SELECT * FROM cp_test_dum...
+ ^
+QUERY:
+DECLARE c5a CURSOR WITH RETURN FOR SELECT * FROM cp_test_dummy;
+
+CONTEXT: SQL function "pdrstest4a" during startup
+SQL function "pdrstest4b" statement 1
+CALL pdrstest4b() \bind \g
+ERROR: relation "cp_test_dummy" does not exist
+LINE 2: DECLARE c5a CURSOR WITH RETURN FOR SELECT * FROM cp_test_dum...
+ ^
+QUERY:
+DECLARE c5a CURSOR WITH RETURN FOR SELECT * FROM cp_test_dummy;
+
+CONTEXT: SQL function "pdrstest4a" during startup
+SQL function "pdrstest4b" statement 1
-- cleanup
DROP PROCEDURE ptest1;
DROP PROCEDURE ptest1s;
DROP PROCEDURE ptest2;
-DROP TABLE cp_test;
+DROP TABLE cp_test, cp_test2, cp_test3;
DROP USER regress_cp_user1;
diff --git a/src/test/regress/sql/create_procedure.sql
b/src/test/regress/sql/create_procedure.sql
index 35b872779e..b79a312f62 100644
--- a/src/test/regress/sql/create_procedure.sql
+++ b/src/test/regress/sql/create_procedure.sql
@@ -242,12 +242,75 @@ CREATE USER regress_cp_user1;
DROP ROUTINE cp_testfunc1(int);
+-- dynamic result sets
+
+CREATE TABLE cp_test2 (a int);
+INSERT INTO cp_test2 VALUES (1), (2), (3);
+CREATE TABLE cp_test3 (x text, y text);
+INSERT INTO cp_test3 VALUES ('abc', 'def'), ('foo', 'bar');
+
+CREATE PROCEDURE pdrstest1()
+LANGUAGE SQL
+DYNAMIC RESULT SETS 2
+AS $$
+DECLARE c1 CURSOR WITH RETURN FOR SELECT * FROM cp_test2;
+DECLARE c2 CURSOR WITH RETURN FOR SELECT * FROM cp_test3;
+$$;
+
+CALL pdrstest1();
+CALL pdrstest1() \bind \g
+
+CREATE PROCEDURE pdrstest2()
+LANGUAGE SQL
+DYNAMIC RESULT SETS 1
+AS $$
+CALL pdrstest1();
+DECLARE c3 CURSOR WITH RETURN FOR SELECT * FROM cp_test2 WHERE a < 2;
+$$;
+
+CALL pdrstest2();
+CALL pdrstest2() \bind \g
+
+CREATE PROCEDURE pdrstest3(INOUT a text)
+LANGUAGE SQL
+DYNAMIC RESULT SETS 1
+AS $$
+DECLARE c4 CURSOR WITH RETURN FOR SELECT * FROM cp_test2;
+SELECT a || a;
+$$;
+
+CALL pdrstest3('x');
+CALL pdrstest3($1) \bind 'y' \g
+
+-- test the nested error handling
+CREATE TABLE cp_test_dummy (a int);
+
+CREATE PROCEDURE pdrstest4a()
+LANGUAGE SQL
+DYNAMIC RESULT SETS 1
+AS $$
+DECLARE c5a CURSOR WITH RETURN FOR SELECT * FROM cp_test_dummy;
+$$;
+
+CREATE PROCEDURE pdrstest4b()
+LANGUAGE SQL
+DYNAMIC RESULT SETS 1
+AS $$
+CALL pdrstest4a();
+$$;
+
+DROP TABLE cp_test_dummy;
+
+CALL pdrstest4b();
+CALL pdrstest4b() \bind \g
+
+
-- cleanup
DROP PROCEDURE ptest1;
DROP PROCEDURE ptest1s;
DROP PROCEDURE ptest2;
-DROP TABLE cp_test;
+DROP TABLE cp_test, cp_test2, cp_test3;
DROP USER regress_cp_user1;
base-commit: 2cb82e2acfba069d00c6bd253d58df03d315672a
--
2.39.2
From 43eab75a74b841459489f5b532d80482a97ab7f2 Mon Sep 17 00:00:00 2001
From: Peter Eisentraut <pe...@eisentraut.org>
Date: Mon, 20 Feb 2023 12:57:33 +0100
Subject: [PATCH v7 2/2] WIP: Dynamic result sets in extended query protocol
This is currently broken due to/since
acb7e4eb6b1c614c68a62fb3a6a5bba1af0a2659.
TODO: consider minor protocol version bump (3.1)
---
doc/src/sgml/protocol.sgml | 19 +++++++++++
src/backend/tcop/postgres.c | 32 ++++++++++++++++---
src/backend/tcop/pquery.c | 6 ++++
src/include/utils/portal.h | 2 ++
src/interfaces/libpq/fe-protocol3.c | 6 ++--
.../regress/expected/create_procedure.out | 22 +++++++++++--
6 files changed, 76 insertions(+), 11 deletions(-)
diff --git a/doc/src/sgml/protocol.sgml b/doc/src/sgml/protocol.sgml
index 93fc7167d4..ec605b12b5 100644
--- a/doc/src/sgml/protocol.sgml
+++ b/doc/src/sgml/protocol.sgml
@@ -959,6 +959,25 @@ <title>Extended Query</title>
an empty query string), ErrorResponse, or PortalSuspended.
</para>
+ <para>
+ Executing a portal may give rise to a <firstterm>dynamic result set
+ sequence</firstterm>. That means the command contained in the portal
+ created additional result sets beyond what it normally returns. (The
+ typical example is calling a stored procedure that creates dynamic result
+ sets.) Dynamic result sets are issued after whatever response the main
+ command issued. Each dynamic result set begins with a RowDescription
+ message followed by zero or more DataRow messages. (Since, as explained
+ above, an Execute message normally does not respond with a RowDescription,
+ the appearance of the first RowDescription marks the end of the primary
+ result set of the portal and the beginning of the first dynamic result
+ set.) The CommandComplete message that concludes the Execute message
+ response follows <emphasis>after</emphasis> all dynamic result sets. Note
+ that dynamic result sets cannot, by their nature, be decribed prior to the
+ execution of the portal. Multiple executions of the same prepared
+ statement could result in dynamic result sets with different row
+ descriptions being returned.
+ </para>
+
<para>
At completion of each series of extended-query messages, the frontend
should issue a Sync message. This parameterless message causes the
diff --git a/src/backend/tcop/postgres.c b/src/backend/tcop/postgres.c
index 98ac9aa012..89da5c7512 100644
--- a/src/backend/tcop/postgres.c
+++ b/src/backend/tcop/postgres.c
@@ -2086,6 +2086,7 @@ exec_execute_message(const char *portal_name, long
max_rows)
const char *sourceText;
const char *prepStmtName;
ParamListInfo portalParams;
+ ListCell *lc;
bool save_log_statement_stats = log_statement_stats;
bool is_xact_command;
bool execute_is_fetch;
@@ -2226,10 +2227,33 @@ exec_execute_message(const char *portal_name, long
max_rows)
receiver,
&qc);
- if (GetReturnableCursors())
- ereport(ERROR,
- errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
- errmsg("dynamic result sets are not yet
supported in extended query protocol"));
+ /*
+ * Run portals for dynamic result sets.
+ */
+ foreach (lc, GetReturnableCursors())
+ {
+ Portal dyn_portal = lfirst(lc);
+
+ if (dest == DestRemoteExecute)
+ SetRemoteDestReceiverParams(receiver, dyn_portal);
+
+ PortalSetResultFormat(dyn_portal, 1, &portal->dynamic_format);
+
+ SendRowDescriptionMessage(&row_description_buf,
+
dyn_portal->tupDesc,
+
FetchPortalTargetList(dyn_portal),
+
dyn_portal->formats);
+
+ PortalRun(dyn_portal,
+ FETCH_ALL,
+ true,
+ true,
+ receiver,
+ receiver,
+ NULL);
+
+ PortalDrop(dyn_portal, false);
+ }
receiver->rDestroy(receiver);
diff --git a/src/backend/tcop/pquery.c b/src/backend/tcop/pquery.c
index 5f0248acc5..6469940935 100644
--- a/src/backend/tcop/pquery.c
+++ b/src/backend/tcop/pquery.c
@@ -641,6 +641,8 @@ PortalSetResultFormat(Portal portal, int nFormats, int16
*formats)
errmsg("bind message has %d result
formats but query has %d columns",
nFormats, natts)));
memcpy(portal->formats, formats, natts * sizeof(int16));
+
+ portal->dynamic_format = 0;
}
else if (nFormats > 0)
{
@@ -649,12 +651,16 @@ PortalSetResultFormat(Portal portal, int nFormats, int16
*formats)
for (i = 0; i < natts; i++)
portal->formats[i] = format1;
+
+ portal->dynamic_format = format1;
}
else
{
/* use default format for all columns */
for (i = 0; i < natts; i++)
portal->formats[i] = 0;
+
+ portal->dynamic_format = 0;
}
}
diff --git a/src/include/utils/portal.h b/src/include/utils/portal.h
index 6f04362dfe..55406b8654 100644
--- a/src/include/utils/portal.h
+++ b/src/include/utils/portal.h
@@ -170,6 +170,8 @@ typedef struct PortalData
TupleDesc tupDesc; /* descriptor for result tuples
*/
/* and these are the format codes to use for the columns: */
int16 *formats; /* a format code for each column */
+ /* Format code for dynamic result sets */
+ int16 dynamic_format;
/*
* Outermost ActiveSnapshot for execution of the portal's queries. For
diff --git a/src/interfaces/libpq/fe-protocol3.c
b/src/interfaces/libpq/fe-protocol3.c
index 8ab6a88416..863a09cf74 100644
--- a/src/interfaces/libpq/fe-protocol3.c
+++ b/src/interfaces/libpq/fe-protocol3.c
@@ -320,10 +320,8 @@ pqParseInput3(PGconn *conn)
{
/*
* A new 'T' message is treated
as the start of
- * another PGresult. (It is
not clear that this is
- * really possible with the
current backend.) We stop
- * parsing until the
application accepts the current
- * result.
+ * another PGresult. We stop
parsing until the
+ * application accepts the
current result.
*/
conn->asyncStatus =
PGASYNC_READY;
return;
diff --git a/src/test/regress/expected/create_procedure.out
b/src/test/regress/expected/create_procedure.out
index 8cc009d1b2..9cec033efb 100644
--- a/src/test/regress/expected/create_procedure.out
+++ b/src/test/regress/expected/create_procedure.out
@@ -402,7 +402,14 @@ CALL pdrstest1();
(2 rows)
CALL pdrstest1() \bind \g
-ERROR: dynamic result sets are not yet supported in extended query protocol
+ a
+---
+ 1
+ 2
+ 3
+(3 rows)
+
+server sent data ("D" message) without prior row description ("T" message)
CREATE PROCEDURE pdrstest2()
LANGUAGE SQL
DYNAMIC RESULT SETS 1
@@ -417,7 +424,11 @@ CALL pdrstest2();
(1 row)
CALL pdrstest2() \bind \g
-ERROR: dynamic result sets are not yet supported in extended query protocol
+ a
+---
+ 1
+(1 row)
+
CREATE PROCEDURE pdrstest3(INOUT a text)
LANGUAGE SQL
DYNAMIC RESULT SETS 1
@@ -439,7 +450,12 @@ CALL pdrstest3('x');
(3 rows)
CALL pdrstest3($1) \bind 'y' \g
-ERROR: dynamic result sets are not yet supported in extended query protocol
+ a
+----
+ yy
+(1 row)
+
+server sent data ("D" message) without prior row description ("T" message)
-- test the nested error handling
CREATE TABLE cp_test_dummy (a int);
CREATE PROCEDURE pdrstest4a()
--
2.39.2
