Innodb buffer pool

  • Two LRU lists, New vs Old = 5:3. Both stores index and data pages
  • New list is mostly explicitly hit pages by the query
  • Old list is mostly read ahead pages. All pages start at the head of the old list, and will move to the new list once it is hit
  • Aurora defaults to 75% of node’s physical memory

Change buffer

  • Not avaiable in Aurora
  • Uses buffer pool space. defaults 25% of the buffer pool, max 50%
  • Cache non-clusterd index change, and merges it only when the said index page is loaded into the buffer pool
  • The motivation is that modification into the secondary index is often very random access, and yet we have to read them into the buffer pool to process it