diff -u b/core/modules/pgsql/src/Driver/Database/pgsql/Schema.php b/core/modules/pgsql/src/Driver/Database/pgsql/Schema.php
--- b/core/modules/pgsql/src/Driver/Database/pgsql/Schema.php
+++ b/core/modules/pgsql/src/Driver/Database/pgsql/Schema.php
@@ -127,17 +127,22 @@
    */
   public function queryTableInformation($table) {
     // Generate a key to reference this table's information on.
-    $key = '"' . $this->connection->getPrefix() . $table . '"';
+    $prefixed_table = $this->connection->getPrefix() . $table;
 
     // Take into account that temporary tables are stored in a different schema.
     // \Drupal\Core\Database\Connection::generateTemporaryTableName() sets the
     // 'db_temporary_' prefix to all temporary tables.
     if (strpos($table, 'db_temporary_') !== FALSE) {
-      $key = $this->getTempNamespaceName() . '.' . $key;
+      $key = $quoted_key = $this->getTempNamespaceName() . '.' . $prefixed_table;
     }
     elseif ($this->defaultSchema != 'public') {
-      $key = '"' . $this->defaultSchema . '".' . $key;
+      $key = $this->defaultSchema . '.' . $prefixed_table;
+      $quoted_key = '"' . $this->defaultSchema . '"."' . $prefixed_table . '"';
     }
+    else {
+      $key = $this->defaultSchema . '.' . $prefixed_table;
+      $quoted_key =  '"' . $prefixed_table . '"';
+    }
 
     if (!isset($this->tableInformation[$key])) {
       $table_information = (object) [
@@ -164,7 +169,7 @@
 OR pg_get_expr(pg_attrdef.adbin, pg_attribute.attrelid) LIKE 'nextval%')
 EOD;
         $result = $this->connection->query($sql, [
-          ':key' => $key,
+          ':key' => $quoted_key,
         ]);
       }
       catch (\Exception $e) {