From 9e823ccfeadc867cfe5290d5956fc055cc9eeeb0 Mon Sep 17 00:00:00 2001
From: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>
Date: Thu, 16 Jul 2026 09:08:31 +0000
Subject: [PATCH] feat: export via COPY TO STDOUT instead of temp view
 (SUPPORT-17025)

Co-Authored-By: tereza.skalova <tereza.skalova@keboola.com>
---
 src/Extractor/CopyAdapter.php                 | 49 ++++---------------
 .../error-invalid-query/expected-stderr       |  2 +-
 .../expected-stdout                           |  4 +-
 3 files changed, 12 insertions(+), 43 deletions(-)

diff --git a/src/Extractor/CopyAdapter.php b/src/Extractor/CopyAdapter.php
index 0b654c24..f03f09b5 100644
--- a/src/Extractor/CopyAdapter.php
+++ b/src/Extractor/CopyAdapter.php
@@ -98,22 +98,17 @@ public function doExport(
         $sql = '\encoding UTF8' . PHP_EOL .
             implode(PHP_EOL, $this->databaseConfig->getInitQueries()) . PHP_EOL;
 
-        if ($this->canUserCreateView() && !$this->isTransactionReadOnly()) {
-            $viewName = uniqid();
-            $sql .= 'CREATE TEMP VIEW "' . $viewName . '" AS ' . $trimmedQuery . ';' . PHP_EOL .
-                sprintf(
-                    "\COPY (%s) TO '%s' WITH CSV DELIMITER ',' FORCE QUOTE *;",
-                    'SELECT * FROM "' . $viewName . '"',
-                    $csvPath,
-                ) . PHP_EOL .
-                'DROP VIEW "' . $viewName . '";';
-        } else {
-            $sql .= sprintf(
-                "\COPY (%s) TO '%s' WITH CSV DELIMITER ',' FORCE QUOTE *;",
+        // Export data using a server-side "COPY ... TO STDOUT" statement redirected to the output
+        // file with the psql "\o" meta-command. Unlike the client-side "\copy" meta-command,
+        // "COPY ... TO STDOUT" is a regular SQL statement, so it supports multi-line queries without
+        // wrapping them in a temporary view. This avoids any DDL (CREATE/DROP TEMP VIEW) on the
+        // source database during export.
+        $sql .= sprintf("\o '%s'", $csvPath) . PHP_EOL .
+            sprintf(
+                "COPY (%s) TO STDOUT WITH CSV DELIMITER ',' FORCE QUOTE *;",
                 $trimmedQuery,
-                $csvPath,
-            );
-        }
+            ) . PHP_EOL .
+            '\o';
 
         try {
             $this->runPsqlProcess($sql, null);
@@ -203,28 +198,4 @@ private function getLastFetchedValue(
 
         return $lastExportedRow[$columnIndex];
     }
-
-    protected function canUserCreateView(): bool
-    {
-        try {
-            return $this->runPsqlProcess(
-                'SELECT has_schema_privilege(current_schema(), \'CREATE\');',
-                null,
-            ) === 't';
-        } catch (CopyAdapterException $e) {
-            throw new CopyAdapterQueryException($e->getMessage(), 0, $e);
-        }
-    }
-
-    protected function isTransactionReadOnly(): bool
-    {
-        try {
-            return $this->runPsqlProcess(
-                'SHOW transaction_read_only;',
-                null,
-            ) === 'on';
-        } catch (CopyAdapterException $e) {
-            throw new CopyAdapterQueryException($e->getMessage(), 0, $e);
-        }
-    }
 }
diff --git a/tests/functional/error-invalid-query/expected-stderr b/tests/functional/error-invalid-query/expected-stderr
index 5aeffd07..eb354bea 100644
--- a/tests/functional/error-invalid-query/expected-stderr
+++ b/tests/functional/error-invalid-query/expected-stderr
@@ -1,3 +1,3 @@
-Export by "Copy" adapter failed: ERROR:  column "something" does not exist LINE 1: CREATE TEMP VIEW "%x" AS SELECT something, fake;%A
+Export by "Copy" adapter failed: ERROR:  column "something" does not exist LINE 1: COPY (SELECT something, fake) TO STDOUT WITH CSV DELIMITER '...%A
 Export by "PDO" adapter failed: [in.c-main.escaping]: DB query failed: SQLSTATE[42703]: Undefined column: 7 ERROR:  column "something" does not exist%A Tried 5 times.
 [in.c-main.escaping]: DB query failed: SQLSTATE[42703]: Undefined column: 7 ERROR:  column "something" does not exist %A Tried 5 times.
diff --git a/tests/functional/run-action-row-debug-logging/expected-stdout b/tests/functional/run-action-row-debug-logging/expected-stdout
index 77c7f625..21749704 100644
--- a/tests/functional/run-action-row-debug-logging/expected-stdout
+++ b/tests/functional/run-action-row-debug-logging/expected-stdout
@@ -2,7 +2,5 @@
 Creating PDO connection to "pgsql:host=%s;port=5432;dbname=postgres;".
 Exporting "sales" to "in.c-main.escaping".
 Exporting by "Copy" adapter.
-[%s] DEBUG: Running query: "SELECT has_schema_privilege(current_schema(), 'CREATE');". [] []
-[%s] DEBUG: Running query: "SHOW transaction_read_only;". [] []
-[%s] DEBUG: Running query: "\encoding UTF8  CREATE TEMP VIEW "%s" AS SELECT * FROM escaping; \COPY (SELECT * FROM "%s") TO '/tmp/run-%s.%s/out/tables/in.c-main.escaping.csv' WITH CSV DELIMITER ',' FORCE QUOTE *; DROP VIEW "%s";". [] []
+[%s] DEBUG: Running query: "\encoding UTF8  \o '/tmp/run-%s.%s/out/tables/in.c-main.escaping.csv' COPY (SELECT * FROM escaping) TO STDOUT WITH CSV DELIMITER ',' FORCE QUOTE *; \o". [] []
 Exported "7" rows to "in.c-main.escaping".