执行计划打印文本格式函数，该函数只是打印其中一个树节点：

snippet.c

/*
 * ExplainPrintPlan -
 *	  convert a QueryDesc's plan tree to text and append it to es->str
 *
 * The caller should have set up the options fields of *es, as well as
 * initializing the output buffer es->str.  Also, output formatting state
 * such as the indent level is assumed valid.  Plan-tree-specific fields
 * in *es are initialized here.
 *
 * NB: will not work on utility statements
 */
void
ExplainPrintPlan(ExplainState *es, QueryDesc *queryDesc)

打赏作者以资鼓励：