Optimizing query planning in Vitess: a step-by-step approach

This post details a new query planning model in Vitess where each optimization step results in a runnable plan. This contrasts with the previous top-down approach and offers benefits such as simpler understanding, ease of testing, and the ability to use arbitrary expressions in ordering, grouping, and aggregations. The post illustrates these benefits with an example query and its step-by-step optimization process under the new model.