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MySQL Internals

MySQL Scalar Subquery Unnesting transformation

Scalar subquery unnesting is a transformation technique that the MySQL optimizer uses to optimize queries involving scalar subqueries. Scalar subqueries return a single value. You typically use them in expressions or as part of the […]

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MySQL Performance

How invisible indexes in MySQL 8 works?

In MySQL 8, invisible indexes are a feature that allows you to create an index without it being used by the optimizer. This can be useful in situations where you want to test the impact […]

MySQL Performance

Optimizing MySQL 8 Performance with Group Commit

Comprehensive Guide to Optimizing MySQL 8 Performance with Group Commit: Understanding, Fine-Tuning System Variables, and Monitoring Techniques for Enhanced Throughput and Reduced Disk I/O Overhead Group commit in MySQL 8 is a critical feature that […]

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MySQL Performance

When MySQL ignores histograms?

MySQL can ignore histograms in the query optimizer when it determines that using the histograms would not provide any benefit to the query execution plan. This can occur in several cases, including: Why MySQL ignores […]