From 18ce3a4ab22d2984f8540ab480979c851dae5338 Mon Sep 17 00:00:00 2001
From: Kevin Grittner <kgrittn@postgresql.org>
Date: Fri, 31 Mar 2017 23:17:18 -0500
Subject: Add infrastructure to support EphemeralNamedRelation references.

A QueryEnvironment concept is added, which allows new types of
objects to be passed into queries from parsing on through
execution.  At this point, the only thing implemented is a
collection of EphemeralNamedRelation objects -- relations which
can be referenced by name in queries, but do not exist in the
catalogs.  The only type of ENR implemented is NamedTuplestore, but
provision is made to add more types fairly easily.

An ENR can carry its own TupleDesc or reference a relation in the
catalogs by relid.

Although these features can be used without SPI, convenience
functions are added to SPI so that ENRs can easily be used by code
run through SPI.

The initial use of all this is going to be transition tables in
AFTER triggers, but that will be added to each PL as a separate
commit.

An incidental effect of this patch is to produce a more informative
error message if an attempt is made to modify the contents of a CTE
from a referencing DML statement.  No tests previously covered that
possibility, so one is added.

Kevin Grittner and Thomas Munro
Reviewed by Heikki Linnakangas, David Fetter, and Thomas Munro
with valuable comments and suggestions from many others
---
 src/test/regress/sql/with.sql | 3 +++
 1 file changed, 3 insertions(+)

(limited to 'src/test/regress/sql/with.sql')

diff --git a/src/test/regress/sql/with.sql b/src/test/regress/sql/with.sql
index 08ddc8bae0..8ae5184d0f 100644
--- a/src/test/regress/sql/with.sql
+++ b/src/test/regress/sql/with.sql
@@ -1028,3 +1028,6 @@ DROP RULE y_rule ON y;
 create table foo (with baz);  -- fail, WITH is a reserved word
 create table foo (with ordinality);  -- fail, WITH is a reserved word
 with ordinality as (select 1 as x) select * from ordinality;
+
+-- check sane response to attempt to modify CTE relation
+WITH d AS (SELECT 42) INSERT INTO d VALUES (1);
-- 
cgit v1.2.1

