Indexing overview

Indexing is how Magento transforms data such as products and categories, to improve the performance of your storefront. As data changes, the transformed data must be updated or reindexed. Magento has a very sophisticated architecture that stores lots of merchant data (including catalog data, prices, users, and stores) in many database tables. To optimize storefront performance, Magento accumulates data into special tables using indexers.

For example, if you change the price of an item from $4.99 to $3.99. Magento must reindex the price change to display it on your storefront.

Without indexing, Magento would have to calculate the price of every product on the fly, taking into account shopping cart price rules, bundle pricing, discounts, tier pricing, etc. Loading the price for a product would take a long time, possibly resulting in cart abandonment.

Indexing terminology

Original data entered to the system. Dictionaries are organized in normal form to facilitate maintenance (updating the data).
Representation of the original data for optimized reading and searching. Indexes can contain results of aggregations and various calculations. Index data can be always re-created from a dictionary using a certain algorithm.
Object that creates an index.

Create custom indexers

Magento contains several indexers out of the box, but you might want to add your own if your customization requires data searches, which are not optimized by the Magento default indexers.

This topic provides a high level description of how indexing is implemented from a developer’s point of view, and practical advice for how to add your own indexer.

How Magento implements indexing

The following components are involved in the indexing process:

Component Description
Magento_Indexer Implements:
  • indexer declaration
  • indexer running
  • indexer running mode configuration
  • indexer status
  • Allows tracking database changes for a certain entity (product, category, etc.) and running change handler.
  • Emulates the materialized view technology for MySQL using triggers and separate materialization process (provides executing PHP code instead of SQL queries, which allows materializing multiple queries).

Magento_Indexer replaces the Magento 1.x Magento_Index module. Use Magento_Indexer for all new development.

Indexing types

Each index can perform the following types of reindex operations:

  • Full reindex, which means rebuilding all the indexing-related database tables

    Full reindexing can be caused by a variety of things, including creating a new web store or new customer group.

    You can optionally fully reindex at any time using the command line.

  • Partial reindex, which means rebuilding the database tables only for the things that changed (like changing a single product attribute or price)

The type of reindex performed in each particular case depends on the type of changes made in the dictionary or in the system. This dependency is specific for each indexer.

The following figure shows the logic for partial reindexing.

Partial indexing workflow

Indexer status

Depending on whether index data is up to date, an indexer status value is one of the following:

Database Status Admin Status Description
valid Ready Data is synchronized, no reindex required
invalid Reindex Required The original data was changed, the index should be updated
working Processing Indexing is in progress

The database status can be seen when viewing the SQL table indexer_state. The admin status can be seen when viewing the indexer grid in Admin or when running the index status from the CLI.

The Magento indexing mechanism uses the status value in reindex triggering process. You can check the status of an indexer in the Admin panel in System > Tools > Index Management or manually using the command line.

Using application lock mode for reindex processes

Starting with 2.4.3, you can enable use_application_lock mode for reindexing through the use of environment variables or by configuring the app/etc/env.php file like so:

return [
    'indexer' => [
        'use_application_lock' => true

In case of a failure during the reindexing of a certain indexer, having this mode enabled will return a more accurate status of the indexer. The status can be obtained from the indexer grid in the Admin or through the bin/magento indexer:status command in the CLI.

The status values in the indexer_state or mview_state database tables may not be the same as what is observed, because they sometimes do not get updated when an indexer fails.

An additional benefit of this mode is that the Magento application will, internally, also see a more accurate status of the indexers and if an indexer failed, Magento will now see this and the cronjob will pick up the indexer to try it again. Without this mode, it was necessary to manually reset the indexer when it failed. With this mode enabled, this should no longer be the case if the reindexing doesn’t fail again during the next attempt.

Indexing modes

Reindexing can be performed in two modes:

  • Update on Save - index tables are updated immediately after the dictionary data is changed.

Update on Save indexers must use custom code (plugins, events or any other working approach) in order to trigger reindexing when entities are saved/deleted etc.

  • Update by Schedule - index tables are updated by cron job according to the configured schedule.

Update by Schedule does not support the customer_grid indexer. You must either use Update on Save or reindex the customer grid manually (bin/magento indexer:reindex customer_grid). See the Help Center article.

To set these options:

  1. Log in to the Admin.
  2. Click System > Tools > Index Management.
  3. Select the checkbox next to each type of indexer to change.
  4. From the Actions list, click the indexing mode.
  5. Click Submit.

You can also reindex from the command line

The following figure shows an example of setting indexers to Update by Schedule:

Changing indexer modes


The mview.xml file is used to track database changes for a certain entity.

For example part of Magento/Catalog/etc/mview.xml is tracking category to product relation described in the following record:

<!-- ... -->
<view id="catalog_category_product" class="Magento\Catalog\Model\Indexer\Category\Product" group="indexer">
    <table name="catalog_category_entity" entity_column="entity_id" />
    <table name="catalog_category_entity_int" entity_column="entity_id" />
<!-- ... -->

Explanation of nodes:

  • The view node defines an indexer. The id attribute is a name of the indexer table, the class attribute is indexer executor, the group attribute defines the indexer group.
  • The subscriptions node is a list of tables for tracking changes.
  • The table node defines the certain table to observe and track changes. The attribute name is a name of an observable table, the attribute entity_column is an identifier column of entity to be re-indexed. So, in case of catalog_category_product, whenever one or more categories is saved, updated or deleted in catalog_category_entity the execute method of Magento\Catalog\Model\Indexer\Category\Product will be called with argument ids containing ids of entities from column defined under entity_column attribute. If indexer type is set to “Update on Save” the method is called right away after the operation. If it set to “Update by Schedule” the mechanism creates a record in the change log table using MYSQL triggers.

A change log table is created according to the naming rule - INDEXER_TABLE_NAME + ‘_cl’, in case of catalog_category_product it will be catalog_category_product_cl. The table contains the version_id auto-increment column and entity_id column that contains identifiers of entities to be re-indexed. For each table node the framework automatically creates MYSQL AFTER triggers for each possible event (INSERT, UPDATE, DELETE).

For the table catalog_category_entity triggers will be created with the following statements. INSERT operation:

    INSERT IGNORE INTO `catalog_category_product_cl` (`entity_id`) VALUES (NEW.`entity_id`);

UPDATE operation:

    IF (NEW.`entity_id` <=> OLD.`entity_id`
        OR NEW.`attribute_set_id` <=> OLD.`attribute_set_id`
        OR NEW.`parent_id` <=> OLD.`parent_id`
        OR NEW.`created_at` <=> OLD.`created_at`
        OR NEW.`path` <=> OLD.`path`
        OR NEW.`position` <=> OLD.`position`
        OR NEW.`level` <=> OLD.`level`
        OR NEW.`children_count` <=> OLD.`children_count`)
            THEN INSERT IGNORE INTO `catalog_category_product_cl` (`entity_id`) VALUES (NEW.`entity_id`);
    END IF;

DELETE operation:

    INSERT IGNORE INTO `catalog_category_product_cl` (`entity_id`) VALUES (OLD.`entity_id`);

The method Magento\Framework\Mview\ViewInterface::update is responsible for handling records in the changelog. The method is being called by CRON and it defines IDs to be re-indexed from the change log by last applied version_id and calls the execute method for each particular indexer with IDs as an argument.

How to reindex

You can reindex by:

Magento indexers

The Magento Open Source application implements the following indexers (use bin/magento indexer:info to list the indexers):

Indexer name Indexer method name Indexer class Description
Design Config Grid design_config_grid Magento\Theme\Model\Indexer\Design\Config  
Customer Grid customer_grid Magento\Framework\Indexer\Action\Entity Rebuilds the customer grid index. Not supported by the Update by Schedule indexing mode. See the Help Center article.
Category products catalog_category_product Magento\Catalog\Model\Indexer\Category\Product Creates category/products association
Product categories catalog_product_category Magento\Catalog\Model\Indexer\Product\Category Creates category/products association
Product price catalog_product_price Magento\Catalog\Model\Indexer\Product\Price Pre-calculates product prices
Product entity attribute value catalog_product_attribute Magento\Catalog\Model\Indexer\Product\Eav Reorganizes the EAV product structure to flat structure
Stock cataloginventory_stock Magento\CatalogInventory\Model\Indexer\Stock  
Catalog rule product catalogrule_rule Magento\CatalogRule\Model\Indexer\Rule\RuleProductIndexer  
Catalog product rule catalogrule_product Magento\CatalogRule\Model\Indexer\Product\ProductRuleIndexer  
Catalog search catalogsearch_fulltext Magento\CatalogSearch\Model\Indexer\Fulltext  

Adobe Commerce also provides the following indexers:

Indexer name Indexer method name Indexer class Description
Product/Target Rule targetrule_product_rule Magento\TargetRule\Model\Indexer\TargetRule\Product\Rule Indexes product/rule association
Target Rule/Product targetrule_rule_product Magento\TargetRule\Model\Indexer\TargetRule\Rule\Product Indexes rule/product association
Sales Rule salesrule_rule Magento\AdvancedSalesRule\Model\Indexer\SalesRule Indexes sales rule