From 7ec63b27d005317d27a24e9ceac8ede520b7cd72 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Petr=20S=CC=8Ckoda?= <commits@skodak.org>
Date: Wed, 11 Jul 2012 15:54:03 +0200
Subject: [PATCH] MDL-34271 cleanup mysql engine hack before adding similar
 collation hack

---
 lib/ddl/mysql_sql_generator.php           | 19 ++++--------
 lib/dml/mysqli_native_moodle_database.php | 36 ++++++++++++++---------
 2 files changed, 28 insertions(+), 27 deletions(-)

diff --git a/lib/ddl/mysql_sql_generator.php b/lib/ddl/mysql_sql_generator.php
index 6ae310f6411..99d118d9349 100644
--- a/lib/ddl/mysql_sql_generator.php
+++ b/lib/ddl/mysql_sql_generator.php
@@ -117,23 +117,16 @@ class mysql_sql_generator extends sql_generator {
      * by any of its comments, indexes and sequence creation SQL statements.
      */
     public function getCreateTableSQL($xmldb_table) {
-        // first find out if want some special db engine
-        $engine = null;
-        if (method_exists($this->mdb, 'get_dbengine')) {
-            $engine = $this->mdb->get_dbengine();
-        }
-
+        // First find out if want some special db engine.
+        $engine = $this->mdb->get_dbengine();
         $sqlarr = parent::getCreateTableSQL($xmldb_table);
 
-        if (!$engine) {
-            // we rely on database defaults
-            return $sqlarr;
-        }
-
-        // let's inject the engine into SQL
+        // Let's inject the extra MySQL tweaks.
         foreach ($sqlarr as $i=>$sql) {
             if (strpos($sql, 'CREATE TABLE ') === 0) {
-                $sqlarr[$i] .= " ENGINE = $engine";
+                if ($engine) {
+                    $sqlarr[$i] .= " ENGINE = $engine";
+                }
             }
         }
 
diff --git a/lib/dml/mysqli_native_moodle_database.php b/lib/dml/mysqli_native_moodle_database.php
index 93311bd5fd4..5134ac98624 100644
--- a/lib/dml/mysqli_native_moodle_database.php
+++ b/lib/dml/mysqli_native_moodle_database.php
@@ -146,22 +146,28 @@ class mysqli_native_moodle_database extends moodle_database {
             return $this->dboptions['dbengine'];
         }
 
-        $engine = null;
-
-        if (!$this->external) {
-            // look for current engine of our config table (the first table that gets created),
-            // so that we create all tables with the same engine
-            $sql = "SELECT engine FROM INFORMATION_SCHEMA.TABLES WHERE table_schema = DATABASE() AND table_name = '{$this->prefix}config'";
-            $this->query_start($sql, NULL, SQL_QUERY_AUX);
-            $result = $this->mysqli->query($sql);
-            $this->query_end($result);
-            if ($rec = $result->fetch_assoc()) {
-                $engine = $rec['engine'];
-            }
-            $result->close();
+        if ($this->external) {
+            return null;
         }
 
+        $engine = null;
+
+        // Look for current engine of our config table (the first table that gets created),
+        // so that we create all tables with the same engine.
+        $sql = "SELECT engine
+                  FROM INFORMATION_SCHEMA.TABLES
+                 WHERE table_schema = DATABASE() AND table_name = '{$this->prefix}config'";
+        $this->query_start($sql, NULL, SQL_QUERY_AUX);
+        $result = $this->mysqli->query($sql);
+        $this->query_end($result);
+        if ($rec = $result->fetch_assoc()) {
+            $engine = $rec['engine'];
+        }
+        $result->close();
+
         if ($engine) {
+            // Cache the result to improve performance.
+            $this->dboptions['dbengine'] = $engine;
             return $engine;
         }
 
@@ -175,7 +181,7 @@ class mysqli_native_moodle_database extends moodle_database {
         }
         $result->close();
 
-        if (!$this->external and $engine === 'MyISAM') {
+        if ($engine === 'MyISAM') {
             // we really do not want MyISAM for Moodle, InnoDB or XtraDB is a reasonable defaults if supported
             $sql = "SHOW STORAGE ENGINES";
             $this->query_start($sql, NULL, SQL_QUERY_AUX);
@@ -196,6 +202,8 @@ class mysqli_native_moodle_database extends moodle_database {
             }
         }
 
+        // Cache the result to improve performance.
+        $this->dboptions['dbengine'] = $engine;
         return $engine;
     }