Yǔpéng Diāo

Planner: variable control for CTE inline

1

### What problem does this PR solve? Issue Number: close #36514 Problem Summary: We set a system variable to control whether to inline CTE or not. Variable name: `tidb_opt_inline_cte` ###...

Planner: automatically inline CTE when only 1 consumer use it

2

### What problem does this PR solve? Issue Number: close #36295 Problem Summary: We should automatically expand the CTE inline when the CTE query is only used once by the...