Nicely done and much more in-depth than I expected.
I generally find that I don't need to spend much time dealing deeply with query planners, low hanging fruit is quite easy enough to find in the enterprise db world (what, no index . . . bad hacker). I also have the advantage of working primarily in a batch oriented world, where my big data moves are simple nightly jobs. On a good day, I get to hack hierarchical data in a relational model and even blow the dust of boolean logic to do cool if . . then and case logic in the where clause of a SQL query. Good times.
But remembering the simple fact that you can see an access plan generated by the RDBMs of your choice will provide you many "heroic" opportunities when some random application blows up. Add them to your general toolbox along with a generous dose of decent SQL (Celko's books have worked for me) background.
My father is deafly afraid of computers. However he is completely obsessed with baseball stats. In his office there are 6 book shelves as tall as the room. Each shelf is filled with books with thousands of pages containing baseball stats. a few of them are literally from the 1800's (apparently they're worth a lot, his will currently has them being donated to some historical baseball society) he's been a member of SABR for as long as I can remember.
Its rather funny though, he spends hours every day sitting at a desk with paper and a pen calculating matrices of stats. I imagine what has taken him years to write could have probably been completed by a computer in minutes.
I generally find that I don't need to spend much time dealing deeply with query planners, low hanging fruit is quite easy enough to find in the enterprise db world (what, no index . . . bad hacker). I also have the advantage of working primarily in a batch oriented world, where my big data moves are simple nightly jobs. On a good day, I get to hack hierarchical data in a relational model and even blow the dust of boolean logic to do cool if . . then and case logic in the where clause of a SQL query. Good times.
But remembering the simple fact that you can see an access plan generated by the RDBMs of your choice will provide you many "heroic" opportunities when some random application blows up. Add them to your general toolbox along with a generous dose of decent SQL (Celko's books have worked for me) background.