diff --git a/CHANGELOG.md b/CHANGELOG.md
index 4ab6b25b19..6cc293725e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -11,6 +11,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 - Automatic generation on delivery no longer creates a consumable model per received consumable
 - CI: fix Psalm cache directory, drop the stray `glpi-project/tools` composer dependency, declare a unique composer autoloader suffix
+- Plugin upgrade no longer rebuilds tables whose columns already have the expected type, nor replays legacy data migrations, which made it time out on large databases (#616)
 
 ## [2.12.11] - 2026-09-18
 
diff --git a/inc/bill.class.php b/inc/bill.class.php
index 773f982e62..ad9fbc5d84 100644
--- a/inc/bill.class.php
+++ b/inc/bill.class.php
@@ -609,7 +609,10 @@ public static function install(Migration $migration)
                 }
             }
 
-            $migration->changeField($table, "value", "value", "decimal(20,6) NOT NULL DEFAULT '0.000000'");
+            if (!PluginOrderConfig::fieldHasType($table, "value", 'decimal(20,6)')) {
+                $migration->changeField($table, "value", "value", "decimal(20,6) NOT NULL DEFAULT '0.000000'");
+            }
+
             $migration->migrationOneTable($table);
         }
 
diff --git a/inc/config.class.php b/inc/config.class.php
index 8e170183e9..668613d299 100644
--- a/inc/config.class.php
+++ b/inc/config.class.php
@@ -28,7 +28,7 @@
  * -------------------------------------------------------------------------
  */
 
-
+use function Safe\preg_replace;
 
 class PluginOrderConfig extends CommonDBTM
 {
@@ -669,6 +669,33 @@ public function canRenameDocuments()
 
 
     //----------------- Install & uninstall -------------------//
+
+    /**
+     * Tell whether a column already has the expected SQL type, so that an upgrade does
+     * not replay a type change: every CHANGE rebuilds the whole table.
+     *
+     * @param string $table Table name
+     * @param string $field Column name
+     * @param string $type  Expected type, as reported by SHOW COLUMNS (ie. "decimal(20,6)", "int unsigned")
+     *
+     * @return bool true when the column is missing or already has this type
+     */
+    public static function fieldHasType(string $table, string $field, string $type): bool
+    {
+        /** @var DBmysql $DB */
+        global $DB;
+
+        $column = $DB->getField($table, $field, false);
+        if ($column === null) {
+            return true;
+        }
+
+        // MySQL 5.7 and MariaDB report an integer display width ("int(10) unsigned"), MySQL 8 does not
+        $current = preg_replace('/^(tinyint|smallint|mediumint|int|bigint)\(\d+\)/', '$1', strtolower((string) $column['Type']));
+
+        return $current === strtolower($type);
+    }
+
     public static function install(Migration $migration)
     {
         /** @var DBmysql $DB */
diff --git a/inc/deliverystate.class.php b/inc/deliverystate.class.php
index 86203effa6..ed62703047 100644
--- a/inc/deliverystate.class.php
+++ b/inc/deliverystate.class.php
@@ -69,7 +69,10 @@ public static function install(Migration $migration)
             //Upgrade 1.2.0
             $migration->renameTable("glpi_dropdown_plugin_order_deliverystate", $table);
             $migration->changeField($table, "ID", "id", sprintf('int %s NOT NULL auto_increment', $default_key_sign));
-            $migration->changeField($table, "name", "name", "varchar(255) default NULL");
+            if (!PluginOrderConfig::fieldHasType($table, "name", 'varchar(255)')) {
+                $migration->changeField($table, "name", "name", "varchar(255) default NULL");
+            }
+
             $migration->changeField($table, "comments", "comment", "text");
             $migration->migrationOneTable($table);
         }
diff --git a/inc/order.class.php b/inc/order.class.php
index b655b1d0be..e2d35b54fa 100644
--- a/inc/order.class.php
+++ b/inc/order.class.php
@@ -2735,12 +2735,10 @@ public static function install(Migration $migration)
                 "is_recursive",
                 "tinyint NOT NULL default 0",
             );
-            $migration->changeField(
-                $table,
-                "name",
-                "name",
-                "varchar(255) default NULL",
-            );
+            if (!PluginOrderConfig::fieldHasType($table, "name", 'varchar(255)')) {
+                $migration->changeField($table, "name", "name", "varchar(255) default NULL");
+            }
+
             $migration->changeField(
                 $table,
                 "budget",
@@ -2795,12 +2793,10 @@ public static function install(Migration $migration)
                 "states_id",
                 sprintf("int %s NOT NULL default '0'", $default_key_sign),
             );
-            $migration->changeField(
-                $table,
-                "comment",
-                "comment",
-                "text",
-            );
+            if (!PluginOrderConfig::fieldHasType($table, "comment", 'text')) {
+                $migration->changeField($table, "comment", "comment", "text");
+            }
+
             $migration->changeField(
                 $table,
                 "notes",
@@ -2863,12 +2859,10 @@ public static function install(Migration $migration)
                     "end_date",
                     "date default NULL",
                 );
-                $migration->changeField(
-                    "glpi_plugin_order_budgets",
-                    "value",
-                    "value",
-                    "float NOT NULL DEFAULT '0'",
-                );
+                if (!PluginOrderConfig::fieldHasType("glpi_plugin_order_budgets", "value", 'float')) {
+                    $migration->changeField("glpi_plugin_order_budgets", "value", "value", "float NOT NULL DEFAULT '0'");
+                }
+
                 $migration->addKey("glpi_plugin_order_budgets", "entities_id");
                 $migration->addKey("glpi_plugin_order_budgets", "is_deleted");
                 $migration->migrationOneTable("glpi_plugin_order_budgets");
@@ -3023,7 +3017,9 @@ public static function install(Migration $migration)
             $migration->addField($table, "global_discount", "FLOAT NOT NULL default '0'");
 
             //2.7.3
-            $migration->changeField($table, "plugin_order_billstates_id", "plugin_order_billstates_id", sprintf('int %s NOT NULL DEFAULT 0', $default_key_sign));
+            if (!PluginOrderConfig::fieldHasType($table, "plugin_order_billstates_id", trim('int ' . $default_key_sign))) {
+                $migration->changeField($table, "plugin_order_billstates_id", "plugin_order_billstates_id", sprintf('int %s NOT NULL DEFAULT 0', $default_key_sign));
+            }
 
             // Add ecotax fields if they don't exist
             if (!$DB->fieldExists($table, 'ecotax_price')) {
diff --git a/inc/order_item.class.php b/inc/order_item.class.php
index 7d5bd9bc3e..a1b82a7be4 100644
--- a/inc/order_item.class.php
+++ b/inc/order_item.class.php
@@ -2107,26 +2107,29 @@ public static function install(Migration $migration)
             $migration->migrationOneTable($table);
 
             //1.4.0
-            $migration->addField(
+            $vat_added = $migration->addField(
                 $table,
                 "plugin_order_ordertaxes_id",
                 sprintf("INT %s NOT NULL default '0' COMMENT 'RELATION to glpi_plugin_order_ordertaxes (id)'", $default_key_sign),
             );
             $migration->migrationOneTable($table);
 
-            /* Migrate VAT */
-            foreach ($DB->request(['FROM' => 'glpi_plugin_order_orders']) as $data) {
-                $migration->addPostQuery(
-                    $DB->buildUpdate(
-                        'glpi_plugin_order_orders_items',
-                        ['plugin_order_ordertaxes_id' => $data['plugin_order_ordertaxes_id']],
-                        ['plugin_order_orders_id' => $data['id']],
-                    ),
-                );
+            /* Migrate VAT, only when the column has just been created: one query per order
+               on every upgrade makes the migration time out on large databases */
+            if ($vat_added) {
+                foreach ($DB->request(['FROM' => 'glpi_plugin_order_orders']) as $data) {
+                    $migration->addPostQuery(
+                        $DB->buildUpdate(
+                            'glpi_plugin_order_orders_items',
+                            ['plugin_order_ordertaxes_id' => $data['plugin_order_ordertaxes_id']],
+                            ['plugin_order_orders_id' => $data['id']],
+                        ),
+                    );
+                }
             }
 
             //1.5.0
-            $migration->addField($table, "entities_id", sprintf("INT %s NOT NULL DEFAULT '0'", $default_key_sign));
+            $entities_added = $migration->addField($table, "entities_id", sprintf("INT %s NOT NULL DEFAULT '0'", $default_key_sign));
             $migration->addField($table, "is_recursive", "TINYINT NOT NULL DEFAULT '0'");
             $migration->addField($table, "plugin_order_bills_id", sprintf("INT %s NOT NULL DEFAULT '0'", $default_key_sign));
             $migration->addField($table, "plugin_order_billstates_id", sprintf("INT %s NOT NULL DEFAULT '0'", $default_key_sign));
@@ -2137,62 +2140,51 @@ public static function install(Migration $migration)
             $migration->migrationOneTable($table);
 
             //Change format for prices : from float to decimal
-            $migration->changeField(
-                $table,
-                "price_taxfree",
-                "price_taxfree",
-                "decimal(20,6) NOT NULL DEFAULT '0.000000'",
-            );
-            $migration->changeField(
-                $table,
-                "price_discounted",
-                "price_discounted",
-                "decimal(20,6) NOT NULL DEFAULT '0.000000'",
-            );
-            $migration->changeField(
-                $table,
-                "price_ati",
-                "price_ati",
-                "decimal(20,6) NOT NULL DEFAULT '0.000000'",
-            );
-            $migration->changeField(
-                $table,
-                "discount",
-                "discount",
-                "decimal(20,6) NOT NULL DEFAULT '0.000000'",
-            );
+            foreach (['price_taxfree', 'price_discounted', 'price_ati', 'discount'] as $field) {
+                if (!PluginOrderConfig::fieldHasType($table, $field, 'decimal(20,6)')) {
+                    $migration->changeField(
+                        $table,
+                        $field,
+                        $field,
+                        "decimal(20,6) NOT NULL DEFAULT '0.000000'",
+                    );
+                }
+            }
 
             //Drop unused fields from previous migration
             $migration->dropField($table, "price_taxfree2");
             $migration->dropField($table, "price_discounted2");
             $migration->migrationOneTable($table);
 
-            //Forward entities_id and is_recursive into table glpi_plugin_order_orders_items
-            $query = [
-                'SELECT' => [
-                    'go.entities_id as entities_id',
-                    'go.is_recursive as is_recursive',
-                    'goi.id as items_id',
-                ],
-                'FROM' => [
-                    'glpi_plugin_order_orders as go',
-                    $table . ' as goi',
-                ],
-                'WHERE' => [
-                    'goi.plugin_order_orders_id' => new QueryExpression(DBmysql::quoteName('go.id')),
-                ],
-            ];
-            foreach ($DB->request($query) as $data) {
-                $migration->addPostQuery(
-                    $DB->buildUpdate(
-                        $table,
-                        [
-                            'entities_id' => $data['entities_id'],
-                            'is_recursive' => $data['is_recursive'],
-                        ],
-                        ['id' => $data['items_id']],
-                    ),
-                );
+            //Forward entities_id and is_recursive into table glpi_plugin_order_orders_items,
+            //only when the column has just been created (one query per order line otherwise)
+            if ($entities_added) {
+                $query = [
+                    'SELECT' => [
+                        'go.entities_id as entities_id',
+                        'go.is_recursive as is_recursive',
+                        'goi.id as items_id',
+                    ],
+                    'FROM' => [
+                        'glpi_plugin_order_orders as go',
+                        $table . ' as goi',
+                    ],
+                    'WHERE' => [
+                        'goi.plugin_order_orders_id' => new QueryExpression(DBmysql::quoteName('go.id')),
+                    ],
+                ];
+                foreach ($DB->request($query) as $data) {
+                    $migration->addPostQuery(
+                        $DB->buildUpdate(
+                            $table,
+                            [
+                                'entities_id' => $data['entities_id'],
+                                'is_recursive' => $data['is_recursive'],
+                            ],
+                            ['id' => $data['items_id']],
+                        ),
+                    );
+                }
             }
 
             if (!$DB->fieldExists($table, 'plugin_order_analyticnatures_id')) {
diff --git a/inc/orderpayment.class.php b/inc/orderpayment.class.php
index de87bbdaa9..dfc23f542f 100644
--- a/inc/orderpayment.class.php
+++ b/inc/orderpayment.class.php
@@ -68,7 +68,10 @@ public static function install(Migration $migration)
             //1.2.0
             $migration->renameTable("glpi_dropdown_plugin_order_payment", $table);
             $migration->changeField($table, "ID", "id", sprintf('int %s NOT NULL auto_increment', $default_key_sign));
-            $migration->changeField($table, "name", "name", "varchar(255) default NULL");
+            if (!PluginOrderConfig::fieldHasType($table, "name", 'varchar(255)')) {
+                $migration->changeField($table, "name", "name", "varchar(255) default NULL");
+            }
+
             $migration->changeField($table, "comments", "comment", "text");
             $migration->migrationOneTable($table);
         }
diff --git a/inc/ordertax.class.php b/inc/ordertax.class.php
index ca8a167e91..90f24dc3c4 100644
--- a/inc/ordertax.class.php
+++ b/inc/ordertax.class.php
@@ -78,7 +78,10 @@ public static function install(Migration $migration)
             //1.2.0
             $migration->renameTable("glpi_dropdown_plugin_order_taxes", $table);
             $migration->changeField($table, "ID", "id", sprintf('int %s NOT NULL auto_increment', $default_key_sign));
-            $migration->changeField($table, "name", "name", "varchar(255) default NULL");
+            if (!PluginOrderConfig::fieldHasType($table, "name", 'varchar(255)')) {
+                $migration->changeField($table, "name", "name", "varchar(255) default NULL");
+            }
+
             $migration->changeField($table, "comments", "comment", "text");
             $migration->migrationOneTable($table);
 
diff --git a/inc/reference.class.php b/inc/reference.class.php
index 029953e544..c81b1fa68a 100644
--- a/inc/reference.class.php
+++ b/inc/reference.class.php
@@ -1146,12 +1146,10 @@ public static function install(Migration $migration)
                 "is_recursive",
                 "tinyint NOT NULL default '0'",
             );
-            $migration->changeField(
-                $table,
-                "name",
-                "name",
-                "varchar(255) default NULL",
-            );
+            if (!PluginOrderConfig::fieldHasType($table, "name", 'varchar(255)')) {
+                $migration->changeField($table, "name", "name", "varchar(255) default NULL");
+            }
+
             $migration->changeField(
                 $table,
                 "FK_glpi_enterprise",
diff --git a/inc/reference_supplier.class.php b/inc/reference_supplier.class.php
index 7cecf6dced..29d0b0da9f 100644
--- a/inc/reference_supplier.class.php
+++ b/inc/reference_supplier.class.php
@@ -436,6 +436,9 @@ public static function install(Migration $migration)
                 $migration->migrationOneTable("glpi_plugin_order_references_manufacturers");
             }
 
+            //Legacy data forwarding below only applies to a pre-1.2.0 table
+            $is_legacy = $DB->tableExists("glpi_plugin_order_references_manufacturers");
+
             //1.2.0
             $migration->renameTable("glpi_plugin_order_references_manufacturers", $table);
             $migration->addField($table, "is_recursive", sprintf("int %s NOT NULL default '0'", $default_key_sign));
@@ -465,40 +468,38 @@ public static function install(Migration $migration)
                 "suppliers_id",
                 sprintf("int %s NOT NULL default '0' COMMENT 'RELATION to glpi_suppliers (id)'", $default_key_sign),
             );
-            $migration->changeField(
-                $table,
-                "reference_code",
-                "reference_code",
-                "varchar(255) default NULL",
-            );
-            $migration->changeField(
-                $table,
-                "price_taxfree",
-                "price_taxfree",
-                "decimal(20,6) NOT NULL DEFAULT '0.000000'",
-            );
+            if (!PluginOrderConfig::fieldHasType($table, "reference_code", 'varchar(255)')) {
+                $migration->changeField($table, "reference_code", "reference_code", "varchar(255) default NULL");
+            }
+
+            if (!PluginOrderConfig::fieldHasType($table, "price_taxfree", 'decimal(20,6)')) {
+                $migration->changeField($table, "price_taxfree", "price_taxfree", "decimal(20,6) NOT NULL DEFAULT '0.000000'");
+            }
+
             $migration->migrationOneTable($table);
 
-            //1.5.0
-            $query = [
-                'SELECT' => [
-                    'entities_id',
-                    'is_recursive',
-                    'id',
-                ],
-                'FROM' => 'glpi_plugin_order_references',
-            ];
-            foreach ($DB->request($query) as $data) {
-                $migration->addPostQuery(
-                    $DB->buildUpdate(
-                        'glpi_plugin_order_references_suppliers',
-                        [
-                            'entities_id' => $data['entities_id'],
-                            'is_recursive' => $data['is_recursive'],
-                        ],
-                        ['plugin_order_references_id' => $data['id']],
-                    ),
-                );
+            //1.5.0, replayed on every upgrade otherwise (one query per reference)
+            if ($is_legacy) {
+                $query = [
+                    'SELECT' => [
+                        'entities_id',
+                        'is_recursive',
+                        'id',
+                    ],
+                    'FROM' => 'glpi_plugin_order_references',
+                ];
+                foreach ($DB->request($query) as $data) {
+                    $migration->addPostQuery(
+                        $DB->buildUpdate(
+                            'glpi_plugin_order_references_suppliers',
+                            [
+                                'entities_id' => $data['entities_id'],
+                                'is_recursive' => $data['is_recursive'],
+                            ],
+                            ['plugin_order_references_id' => $data['id']],
+                        ),
+                    );
+                }
             }
         }
     }
diff --git a/inc/surveysupplier.class.php b/inc/surveysupplier.class.php
index c92d9d366a..ea9d4ac42a 100644
--- a/inc/surveysupplier.class.php
+++ b/inc/surveysupplier.class.php
@@ -556,38 +556,40 @@ public static function install(Migration $migration)
                 "suppliers_id",
                 sprintf("int %s NOT NULL default '0' COMMENT 'RELATION to glpi_suppliers (id)'", $default_key_sign),
             );
-            $migration->changeField(
-                $table,
-                "comment",
-                "comment",
-                "text",
-            );
-            $migration->addField($table, "entities_id", sprintf("int %s NOT NULL default '0'", $default_key_sign));
+            if (!PluginOrderConfig::fieldHasType($table, "comment", 'text')) {
+                $migration->changeField($table, "comment", "comment", "text");
+            }
+
+            $entities_added = $migration->addField($table, "entities_id", sprintf("int %s NOT NULL default '0'", $default_key_sign));
             $migration->addField($table, "is_recursive", "tinyint NOT NULL default '0'");
             $migration->addKey($table, "plugin_order_orders_id");
             $migration->addKey($table, "suppliers_id");
             $migration->migrationOneTable($table);
 
-            $query = [
-                'SELECT' => [
-                    'suppliers_id',
-                    'entities_id',
-                    'is_recursive',
-                    'id',
-                ],
-                'FROM' => 'glpi_plugin_order_orders',
-            ];
-            foreach ($DB->request($query) as $data) {
-                $migration->addPostQuery(
-                    $DB->buildUpdate(
-                        'glpi_plugin_order_surveysuppliers',
-                        [
-                            'entities_id' => $data['entities_id'],
-                            'is_recursive' => $data['is_recursive'],
-                        ],
-                        ['plugin_order_orders_id' => $data['id']],
-                    ),
-                );
+            //Forward the order entity only when the column has just been created
+            //(one query per order on every upgrade otherwise)
+            if ($entities_added) {
+                $query = [
+                    'SELECT' => [
+                        'suppliers_id',
+                        'entities_id',
+                        'is_recursive',
+                        'id',
+                    ],
+                    'FROM' => 'glpi_plugin_order_orders',
+                ];
+                foreach ($DB->request($query) as $data) {
+                    $migration->addPostQuery(
+                        $DB->buildUpdate(
+                            'glpi_plugin_order_surveysuppliers',
+                            [
+                                'entities_id' => $data['entities_id'],
+                                'is_recursive' => $data['is_recursive'],
+                            ],
+                            ['plugin_order_orders_id' => $data['id']],
+                        ),
+                    );
+                }
             }
         }
     }