| 阶段 | 核心函数 | 关键动作 | 节点操作 |
|---|
| Init | ExecutorStart
| 解析计划树，构建运行时状态树，打开表，编译表达式。 | ExecInitNode: Plan -> PlanState
|
| Run | ExecutorRun
| 循环拉取数据，逐行处理，发送给客户端 | ExecProcNode: TupleTableSlot, ExprContext |
| Finish | ExecutorFinish | 执行排队的 AFTER 触发器，更新统计信息 | AfterTriggerEndQuery |
| End | ExecutorEnd
| 关闭文件/扫描描述符，销毁临时占用资源 | ExecEndNode |
/* ... */
/* Portal & Executor */
CreatePortal
PortalDefineQuery // portal->stmts = plantree_list;
PortalStart // Prepare a portal for execution. params, strategy, queryDesc
ExecutorStart // prepare the plan for execution
standard_ExecutorStart
InitPlan /* Initialize the plan state tree */
**ExecInitNode** | ExecInitSeqScan
ExecOpenScanRelation
PORTAL_READY
PortalRun | PortalRunSelect
/* Executor */
ExecutorRun | tandard_ExecutorRun | ExecutePlan // Processes the query plan until retrieved 'numberTuples' tuples
**ExecProcNode** | ExecSeqScan
ExecScan | ExecScanFetch | SeqNext // executor module
/* Access + Storage*/
table_scan_getnextslot | heap_getnextslot | heapgettup_pagemode
heapgetpage | ReadBufferExtended | ReadBuffer_common
PortalDrop
PortalCleanup
ExecutorFinish
ExecPostprocessPlan
AfterTriggerEndQuery
ExecutorEnd
ExecEndPlan
**ExecEndNode** | ExecEndSeqScan
FreeQueryDesc