What this PR does / why we need it:

1）explain analyze
2） 使用set memory_tracking_mode=peak来观测，记录到日志里
可以观察一个查询的峰值内存消耗，用于内存的容量规划

Which issue this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close that issue when PR gets merged): fixes #

Special notes for your reviewer:

Release note: