Price Indexer fails with large catalogs

[ishakhsuvarov]

Preconditions (*)

1. Magento with MSI is installed and configured in a single-stock mode.
2. Large performance profile generated

Steps to reproduce (*)

1. Run reindex with large profile applied

Expected result (*)

✅Success

Actual result (*)

❌DB Query is executed enormously long time.

Possible Solution

Product Price Indexer depends on stock index. Because of this ModifySelectInProductPriceIndexFilter plugin was introduce, which modifies original query to use inventory_stock_* tables.

By current design, inventory_stock_1 table is not a real table but a MySql VIEW, which may perform significantly slower in specific cases, like the one described above. One of the possible solutions, confirmed to be solving the issue, is adding conditional logic to the plugin, which does not allow usage of the VIEW when Inventory is operating in single-stock mode.