plan-analyzer.ts•2.26 kB
import { PlanAnalysis, PlanSignal, RiskItem } from './types.js'
export class PlanAnalyzer {
analyze(plan: any): PlanAnalysis {
const summary: string[] = []
const risks: RiskItem[] = []
const signals: PlanSignal[] = []
const json = plan || {}
const text = JSON.stringify(json).toLowerCase()
const flags = {
usingFilesort: text.includes('using filesort') || text.includes('filesort') || text.includes('sorting_operation'),
usingTemporary: text.includes('using temporary') || text.includes('temp table') || text.includes('temporary')
}
// Walk common nodes to produce compact summary
const root = (json && (json.query_block || json))
const walk = (node: any) => {
if (!node) return
const table = node.table_name || node.table?.table_name
const access = node.access_type || node.table?.access_type
const rows = node.rows_examined_per_scan || node.rows || node.table?.rows_examined_per_scan
const filtered = node.filtered || (node.attached_condition ? 'with filter' : '')
if (table || access || rows) summary.push([table, access, rows && `${rows} rows`, filtered].filter(Boolean).join(' / '))
if (node.table) walk(node.table)
if (Array.isArray(node.nested_loop)) node.nested_loop.forEach(walk)
if (node.grouping_operation) walk(node.grouping_operation)
if (node.sorting_operation) walk(node.sorting_operation)
}
walk(root)
if (flags.usingFilesort) {
risks.push({ id: 'filesort', level: 'should', reason: '存在文件排序/排序操作，可能造成额外开销', evidence: { node: 'sorting_operation' } })
signals.push({ id: 'filesort', message: 'Filesort detected' })
}
if (flags.usingTemporary) {
risks.push({ id: 'temporary', level: 'should', reason: '使用临时表，可能带来性能问题', evidence: { node: 'temporary' } })
signals.push({ id: 'temporary', message: 'Temporary table detected' })
}
if (text.includes('full scan') || text.includes('all"')) {
risks.push({ id: 'full_scan', level: 'must', reason: '存在全表扫描', evidence: {} })
signals.push({ id: 'full_scan', message: 'Full table scan' })
}
return { summary, risks, signals, flags }
}
}