From cb633aa092e83aa95b1e0483d6d6ce731bf6bdfe Mon Sep 17 00:00:00 2001
From: Dimitri Fontaine <dim@tapoueh.org>
Date: Mon, 20 Aug 2018 11:52:59 +0200
Subject: [PATCH] Refrain from some introspections on non-PGDG PostgreSQL
 variants.

When dealing with PostgreSQL protocol compatible databases, often enough
they don't support the same catalogs as PostgreSQL itself. Redshift for
instance lacks foreign key support.
---
 src/load/load-file.lisp      |  4 +++-
 src/pgsql/pgsql-schema.lisp  | 30 ++++++++++++++++++------------
 src/sources/pgsql/pgsql.lisp | 34 ++++++++++++++++++----------------
 3 files changed, 39 insertions(+), 29 deletions(-)

diff --git a/src/load/load-file.lisp b/src/load/load-file.lisp
index 19819e5..7d36d12 100644
--- a/src/load/load-file.lisp
+++ b/src/load/load-file.lisp
@@ -42,7 +42,9 @@
     (handler-case
         (with-pgsql-connection (pgconn)
           (setf pgsql-catalog
-                (fetch-pgsql-catalog (db-name pgconn) :table (target copy)))
+                (fetch-pgsql-catalog (db-name pgconn)
+                                     :table (target copy)
+                                     :variant (pgconn-variant pgconn)))
 
           ;; if the user didn't tell us the column list of the table, now is
           ;; a proper time to set it in the copy object
diff --git a/src/pgsql/pgsql-schema.lisp b/src/pgsql/pgsql-schema.lisp
index b47c4e5..9ea3d59 100644
--- a/src/pgsql/pgsql-schema.lisp
+++ b/src/pgsql/pgsql-schema.lisp
@@ -5,7 +5,12 @@
 (in-package :pgloader.pgsql)
 
 (defun fetch-pgsql-catalog (dbname
-                            &key table source-catalog including excluding)
+                            &key
+                              table
+                              source-catalog
+                              including
+                              excluding
+                              (variant :pgdg))
   "Fetch PostgreSQL catalogs for the target database. A PostgreSQL
    connection must be opened."
   (let* ((*identifier-case* :quote)
@@ -18,10 +23,10 @@
 
                           (t
                            including))))
-
-    (list-all-sqltypes catalog
-                       :including including
-                       :excluding excluding)
+    (when (eq :pgdg variant)
+      (list-all-sqltypes catalog
+                         :including including
+                         :excluding excluding))
 
     (list-all-columns catalog
                       :table-type :table
@@ -32,14 +37,15 @@
                       :including including
                       :excluding excluding)
 
-    (list-all-fkeys catalog
-                    :including including
-                    :excluding excluding)
+    (when (eq :pgdg variant)
+      (list-all-fkeys catalog
+                      :including including
+                      :excluding excluding)
 
-    ;; fetch fkey we depend on with UNIQUE indexes but that have been
-    ;; excluded from the target list, we still need to take care of them to
-    ;; be able to DROP then CREATE those indexes again
-    (list-missing-fk-deps catalog)
+      ;; fetch fkey we depend on with UNIQUE indexes but that have been
+      ;; excluded from the target list, we still need to take care of them to
+      ;; be able to DROP then CREATE those indexes again
+      (list-missing-fk-deps catalog))
 
     (log-message :debug "fetch-pgsql-catalog: ~d tables, ~d indexes, ~d+~d fkeys"
                  (count-tables catalog)
diff --git a/src/sources/pgsql/pgsql.lisp b/src/sources/pgsql/pgsql.lisp
index e8cab7b..8a45a58 100644
--- a/src/sources/pgsql/pgsql.lisp
+++ b/src/sources/pgsql/pgsql.lisp
@@ -64,27 +64,29 @@
                           :use-result-as-read t
                           :section :pre)
     (with-pgsql-transaction (:pgconn (source-db pgsql))
-      (list-all-sqltypes catalog
+      (let ((variant (pgconn-variant (source-db pgsql))))
+       (when (eq :pgdg variant)
+         (list-all-sqltypes catalog
+                            :including including
+                            :excluding excluding))
+
+       (list-all-columns catalog
                          :including including
                          :excluding excluding)
 
-      (list-all-columns catalog
-                        :including including
-                        :excluding excluding)
+       (when create-indexes
+         (list-all-indexes catalog
+                           :including including
+                           :excluding excluding))
 
-      (when create-indexes
-        (list-all-indexes catalog
-                          :including including
-                          :excluding excluding))
+       (when (and (eq :pgdg variant) foreign-keys)
+         (list-all-fkeys catalog
+                         :including including
+                         :excluding excluding))
 
-      (when foreign-keys
-        (list-all-fkeys catalog
-                        :including including
-                        :excluding excluding))
-
-      ;; return how many objects we're going to deal with in total
-      ;; for stats collection
-      (+ (count-tables catalog) (count-indexes catalog))))
+       ;; return how many objects we're going to deal with in total
+       ;; for stats collection
+       (+ (count-tables catalog) (count-indexes catalog)))))
 
   ;; be sure to return the catalog itself
   catalog)