The Magento 2.3 update has unintentionally caused significant performance issues, due to a CPU load surge triggered by new queries. This causes particular strain on websites with large search-query tables, often rendering admin panels almost unusable. The main culprits are the Popular Search Term Cache, added in the update, the 'num_results > 0' condition, and the DISTINCT operator. Removing the DISTINCT operator from specific queries and inserting search terms into the table in batches or not at all, if feasible, are suggested as mitigating measures. However, these issues persist in Magento 2.4.5-p4, thus calling for continuous monitoring and research for effective remedies. The issue highlights the importance of continuous optimization and performance testing, as system performance can be impacted by even minor components.
Full article here: https://lawsuithelpdesk.com/cracking-the-code-navigating-magento-2-3s-unexpected-cpu-load-spike-and-the-power-of-efficient-query-optimization/