sql tuning: add EXPLAIN views (#3862)
sql tuning: add EXPLAIN views (#3862)

* sql tuning: add EXPLAIN views

* Update explain-views.md

Co-authored-by: Feng Liyuan <66b99b5eb121c249c9911315bee84d44e0da4cc6@gmail.com>

* Update explain-views.md

Co-authored-by: TomShawn <3d0966147538bc5ab020e8dffa2c0b746f9728a6@users.noreply.github.com>

* Update explain-views.md

Co-authored-by: TomShawn <3d0966147538bc5ab020e8dffa2c0b746f9728a6@users.noreply.github.com>

* Update explain-views.md

Co-authored-by: TomShawn <3d0966147538bc5ab020e8dffa2c0b746f9728a6@users.noreply.github.com>

* Update explain-views.md

Co-authored-by: TomShawn <3d0966147538bc5ab020e8dffa2c0b746f9728a6@users.noreply.github.com>

* Update explain-views.md

Co-authored-by: TomShawn <3d0966147538bc5ab020e8dffa2c0b746f9728a6@users.noreply.github.com>

* Update explain-views.md

Co-authored-by: TomShawn <3d0966147538bc5ab020e8dffa2c0b746f9728a6@users.noreply.github.com>

* Update explain-views.md

* Apply suggestions from code review

Co-authored-by: Feng Liyuan <66b99b5eb121c249c9911315bee84d44e0da4cc6@gmail.com>
Co-authored-by: TomShawn <3d0966147538bc5ab020e8dffa2c0b746f9728a6@users.noreply.github.com>
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