Method parse_explain_plan

src/sql-parser/src/parser.rs:9043–9144

Parse an `EXPLAIN ... PLAN` statement, assuming that the `EXPLAIN` token has already been consumed.

(&mut self)

    /// Parse an `EXPLAIN ... PLAN` statement, assuming that the `EXPLAIN` token
    /// has already been consumed.
    fn parse_explain_plan(&mut self) -> Result<Statement<Raw>, ParserError> {
        let start = self.peek_pos();
        let (has_stage, stage) = match self.parse_one_of_keywords(&[
            RAW,
            DECORRELATED,
            LOCALLY,
            OPTIMIZED,
            PHYSICAL,
            OPTIMIZER,
            PLAN,
        ]) {
            Some(RAW) => {
                self.expect_keyword(PLAN)?;
                (true, Some(ExplainStage::RawPlan))
            }
            Some(DECORRELATED) => {
                self.expect_keyword(PLAN)?;
                (true, Some(ExplainStage::DecorrelatedPlan))
            }
            Some(LOCALLY) => {
                self.expect_keywords(&[OPTIMIZED, PLAN])?;
                (true, Some(ExplainStage::LocalPlan))
            }
            Some(OPTIMIZED) => {
                self.expect_keyword(PLAN)?;
                (true, Some(ExplainStage::GlobalPlan))
            }
            Some(PHYSICAL) => {
                self.expect_keyword(PLAN)?;
                (true, Some(ExplainStage::PhysicalPlan))
            }
            Some(OPTIMIZER) => {
                self.expect_keyword(TRACE)?;
                (true, Some(ExplainStage::Trace))
            }
            Some(PLAN) => {
                if self.parse_keyword(INSIGHTS) {
                    (true, Some(ExplainStage::PlanInsights))
                } else {
                    // Use the default plan for the explainee.
                    (true, None)
                }
            }
            None => {
                // Use the default plan for the explainee.
                (false, None)
            }
            _ => unreachable!(),
        };

        let with_options = if self.parse_keyword(WITH) {
            if self.consume_token(&Token::LParen) {
                let options = self.parse_comma_separated(Parser::parse_explain_plan_option)?;
                self.expect_token(&Token::RParen)?;
                options
            } else {
                self.prev_token(); // push back WITH in case it's actually a CTE
                vec![]