NEW Allow InnoDB for FULLTEXT indexes

MyISAM used to be the only one to support it, now InnoDB has caught up.
Unless an engine is set specifically in create_table_options,
this will auto-convert existing MyISAM tables to InnoDb.

Fixes #9242

docs/en/04_Changelogs/4.6.0.md

@@ -0,0 +1,55 @@
+# 4.6.0 (Unreleased)
+
+## Overview {#overview}
+
+ * [MySQL tables are auto-converted from MyISAM to InnoDB](#myisam)
+ 
+## MySQL tables are auto-converted from MyISAM to InnoDB {#myisam}
+
+Beginning with [4.4.0](https://docs.silverstripe.org/en/4/changelogs/4.4.0/),
+our minimum requirement for MySQL is 5.6 (since MySQL 5.5 end of life reached in December 2018).
+Starting with MySQL 5.6, [InnoDB](https://dev.mysql.com/doc/refman/5.6/en/innodb-introduction.html)
+is the new default storage engine,
+replacing the older [MyISAM](https://dev.mysql.com/doc/refman/5.6/en/myisam-storage-engine.html) engine.
+
+Silverstripe CMS already creates InnoDB tables by default,
+mainly in order to benefit from their better support for database transactions.
+Before MySQL 5.6, InnoDB didn't have a `FULLTEXT` search index,
+requiring us to enforce the MyISAM engine when devs opted into this index type
+in their particular setup. There are a few ways in which this opt-in can happen:
+
+ * Adding the [FulltextSearchable](https://github.com/silverstripe/silverstripe-framework/blob/4/src/ORM/Search/FulltextSearchable.php)
+   extension to a DataObject, as described in our 
+   [search docs](https://docs.silverstripe.org/en/4/developer_guides/search/fulltextsearch/)
+ * Defining `'type' => 'fulltext'` in `DataObject::$db` column definitions
+ * Implementing [DBIndexable](https://github.com/silverstripe/silverstripe-framework/blob/4/src/ORM/FieldType/DBIndexable.php)
+   on a custom `DBField` subclass.
+ * Setting `'ENGINE=MyISAM'` in `DataObject::$create_table_options`
+ 
+This search index is not required to enable simple text search
+in the "Pages" section of the CMS, or any ModelAdmin implementations.
+We generally recommend to choose a more powerful
+[search addon](https://addons.silverstripe.org/add-ons?search=fulltext&type=&sort=downloads)
+(e.g. based on Solr or ElasticSearch) for website frontend search use cases. 
+
+As of 4.6.0, a `dev/build` will automatically switch MyISAM tables to InnoDB,
+which automatically recreates any indexes required. If you have large indexes,
+this can extend the duration if this task. As usual, back up your database
+before upgrading, and test upgrades on non-production systems first.
+Our tests indicate that indexes with thousands of records and screen pages
+worth of content (15MB index size) are converted in a few seconds. 
+
+In order to opt out of this change, you can set the engine explicitly
+for your DataObject implementations:
+
+```php
+use SilverStripe\ORM\Connect\MySQLSchemaManager;
+use SilverStripe\ORM\DataObject;
+
+class MyDataObject extends DataObject
+{
+    private static $create_table_options = [
+            MySQLSchemaManager::ID => 'ENGINE=MyISAM'
+    ];
+}
+```

src/ORM/Connect/MySQLSchemaManager.php

@@ -40,10 +40,6 @@ class MySQLSchemaManager extends DBSchemaManager
         }
         if ($indexes) {
             foreach ($indexes as $k => $v) {
-                // force MyISAM if we have a fulltext index
-                if ($v['type'] === 'fulltext') {
-                    $addOptions = 'ENGINE=MyISAM';
-                }
                 $indexSchemas .= $this->getIndexSqlDefinition($k, $v) . ",\n";
             }
         }
@@ -104,31 +100,12 @@ class MySQLSchemaManager extends DBSchemaManager
 
         $dbID = self::ID;
         if ($alteredOptions && isset($alteredOptions[$dbID])) {
-            $indexList = $this->indexList($tableName);
-            $skip = false;
-            foreach ($indexList as $index) {
-                if ($index['type'] === 'fulltext') {
-                    $skip = true;
-                    break;
-                }
-            }
-            if ($skip) {
-                $this->alterationMessage(
-                    sprintf(
-                        "Table %s options not changed to %s due to fulltextsearch index",
-                        $tableName,
-                        $alteredOptions[$dbID]
-                    ),
-                    "changed"
-                );
-            } else {
             $this->query(sprintf("ALTER TABLE \"%s\" %s", $tableName, $alteredOptions[$dbID]));
             $this->alterationMessage(
                 sprintf("Table %s options changed: %s", $tableName, $alteredOptions[$dbID]),
                 "changed"
             );
         }
-        }
 
         $alterations = implode(",\n", $alterList);
         $this->query("ALTER TABLE \"$tableName\" $alterations");

src/ORM/Filters/FulltextFilter.php

@@ -2,7 +2,6 @@
 
 namespace SilverStripe\ORM\Filters;
 
-use SilverStripe\Core\Convert;
 use SilverStripe\ORM\DataQuery;
 use SilverStripe\ORM\DataObject;
 use Exception;
@@ -10,8 +9,7 @@ use Exception;
 /**
  * Filters by full-text matching on the given field.
  *
- * Full-text indexes are only available with MyISAM tables. The following column types are
- * supported:
+ * The following column types are supported:
  *   - Char
  *   - Varchar
  *   - Text

tests/php/ORM/DataObjectSchemaGenerationTest.php

@@ -25,12 +25,6 @@ class DataObjectSchemaGenerationTest extends SapphireTest
         // Start tests
         static::start();
 
-        // enable fulltext option on this table
-        TestIndexObject::config()->update(
-            'create_table_options',
-            array(MySQLSchemaManager::ID => 'ENGINE=MyISAM')
-        );
-
         parent::setUpBeforeClass();
     }
 

tests/php/ORM/Filters/FulltextFilterTest/TestObject.php

@@ -35,7 +35,4 @@ class TestObject extends DataObject implements TestOnly
         ],
     );
 
-    private static $create_table_options = array(
-        MySQLSchemaManager::ID => "ENGINE=MyISAM",
-    );
 }