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clauses.c源码分析 作 者： 审 阅 者： 修改日期：2005年5月20日 clauses.c源码分析 1 1. 文件简介 2 2. 基本概念 2 3. 数据结构 3 4. 函数和宏 3 4.1. 函数分类 3 4.2. 接口说明 4 4.2.1. make_opclause 4 4.2.2. get_leftop 5 4.2.3. get_rightop 5 4.2.4. not_clause 5 4.2.5. make_notclause 5 4.2.6. get_notclausearg 5 4.2.7. or_clause 6 4.2.8. make_orclause 6 4.2.9. and_clause 6 4.2.10. make_andclause 6 4.2.11. make_and_qual 6 4.2.12. make_ands_explicit 7 4.2.13. make_ands_implicit 7 4.2.14. contain_agg_clause 7 4.2.15. contain_agg_clause_walker 7 4.2.16. count_agg_clauses 7 4.2.17. count_agg_clauses_walker 8 4.2.18. expression_returns_set 8 4.2.19. expression_returns_set_walker 8 4.2.20. contain_subplans 8 4.2.21. contain_subplans_walker 8 4.2.22. contain_mutable_functions 9 4.2.23. contain_mutable_functions_walker 9 4.2.24. contain_volatile_functions 9 4.2.25. contain_volatile_functions_walker 9 4.2.26. contain_nonstrict_functions 9 4.2.27. contain_nonstrict_functions_walker 10 4.2.28. is_pseudo_constant_clause 10 4.2.29. is_pseudo_constant_clause_relids 10 4.2.30. pull_constant_clauses 10 4.2.31. has_distinct_on_clause 10 4.2.32. has_distinct_clause 11 4.2.33. NumRelids 11 4.2.34. CommuteClause 11 4.2.35. strip_implicit_coercions 11 4.2.36. set_coercionform_dontcare 11 4.2.37. set_coercionform_dontcare_walker 12 4.2.38. rowtype_field_matches 12 4.2.39. eval_const_expressions 12 4.2.40. estimate_expression_value 12 4.2.41. eval_const_expressions_mutator 12 4.2.42. simplify_or_arguments 13 4.2.43. simplify_and_arguments 13 4.2.44. simplify_function 13 4.2.45. evaluate_function 13 4.2.46. inline_function 14 4.2.47. substitute_actual_parameters 14 4.2.48. substitute_actual_parameters_mutator 14 4.2.49. sql_inline_error_callback 14 4.2.50. evaluate_expr 14 4.2.51. expression_tree_walker 15 4.2.52. query_tree_walker 15 4.2.53. expression_tree_mutator 15 4.2.54. query_tree_mutator 16 4.2.55. query_or_expression_tree_walker 17 4.2.56. query_or_expression_tree_mutator 17 4.3. 算法 / 流程 17 5. 遗留问题 18 5.1. 几点说明 18 文件简介 （该文件解决了什么问题？如何