[This post refers to innodb_ruby version 0.9.11 as of October 2, 2014.]
Many DBAs know that building indexes in “random” order (or really any order that greatly differs from ordered by key) can be much less efficient. However, it’s often hard to really understand why that is. With the “-illustrate” visualization modes available in innodb_ruby, it’s possible to quite easily visualize the structure of indexes. The space-lsn-age-illustrate mode to innodb_space allows visualization of all pages in a space file by “LSN age”, generating something like a heatmap of the space file based on how recently each page was modified.
(Note that a small Ruby script generate_data_simple.rb was used to generate the test tables used below. …
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