perf(cqn4sql): Add benchmark suite

db-service/bench/cases/assoc-to-join-recursive.cjs

@@ -0,0 +1,8 @@
+'use strict'
+
+const cds = require('@sap/cds')
+
+module.exports = {
+  name: 'assoc-to-join: recursive depth 3',
+  buildInput: () => cds.ql`SELECT from my.Genres { ID, parent.parent.parent.name }`,
+}

db-service/bench/cases/assoc-to-join-simple.cjs

@@ -0,0 +1,8 @@
+'use strict'
+
+const cds = require('@sap/cds')
+
+module.exports = {
+  name: 'assoc-to-join: simple',
+  buildInput: () => cds.ql`SELECT from my.Books { ID, author.name }`,
+}

db-service/bench/cases/exists-recursive.cjs

@@ -0,0 +1,8 @@
+'use strict'
+
+const cds = require('@sap/cds')
+
+module.exports = {
+  name: 'exists: recursive depth 3',
+  buildInput: () => cds.ql`SELECT from my.Genres { ID } where exists parent.parent.parent`,
+}

db-service/bench/cases/exists-simple.cjs

@@ -0,0 +1,8 @@
+'use strict'
+
+const cds = require('@sap/cds')
+
+module.exports = {
+  name: 'exists: simple',
+  buildInput: () => cds.ql`SELECT from my.Books { ID } where exists author`,
+}

db-service/bench/cases/expand-recursive.cjs

@@ -0,0 +1,8 @@
+'use strict'
+
+const cds = require('@sap/cds')
+
+module.exports = {
+  name: 'expand: recursive depth 3',
+  buildInput: () => cds.ql`SELECT from my.Genres { ID, parent { parent { parent { name }}} }`,
+}

db-service/bench/cases/expand-simple.cjs

@@ -0,0 +1,8 @@
+'use strict'
+
+const cds = require('@sap/cds')
+
+module.exports = {
+  name: 'expand: simple',
+  buildInput: () => cds.ql`SELECT from my.Authors { ID, books { title } }`,
+}

db-service/bench/cases/simple-select.cjs

@@ -0,0 +1,8 @@
+'use strict'
+
+const cds = require('@sap/cds')
+
+module.exports = {
+  name: 'Most Basic Select',
+  buildInput: () => cds.ql`SELECT from my.Books { ID }`,
+}

db-service/bench/model/schema.cds

@@ -0,0 +1,24 @@
+namespace my;
+
+entity Books {
+  key ID     : Integer;
+      title  : String;
+      stock  : Integer;
+      author : Association to Authors;
+      genre  : Association to Genres;
+}
+
+entity Authors {
+  key ID    : Integer;
+      name  : String;
+      books : Association to many Books
+                on books.author = $self;
+}
+
+entity Genres {
+  key ID       : Integer;
+      name     : String;
+      parent   : Association to Genres;
+      children : Composition of many Genres
+                   on children.parent = $self;
+}

db-service/bench/results/results.csv

@@ -0,0 +1,8 @@
+commit_sha,case,n,min_ms,max_ms,median_ms,p95_ms,mean_ms,mad_ms
+681dc75033f5,Most Basic Select,500,0.019,2.964,0.021,0.070,0.040,0.001
+681dc75033f5,exists: simple,500,0.026,1.038,0.030,0.051,0.034,0.002
+681dc75033f5,assoc-to-join: simple,500,0.034,1.379,0.039,0.075,0.048,0.003
+681dc75033f5,exists: recursive depth 3,500,0.035,0.791,0.040,0.058,0.045,0.003
+681dc75033f5,assoc-to-join: recursive depth 3,500,0.036,0.631,0.046,0.072,0.050,0.003
+681dc75033f5,expand: simple,500,0.060,2.042,0.073,0.116,0.086,0.004
+681dc75033f5,expand: recursive depth 3,500,0.129,2.593,0.162,0.571,0.224,0.015

db-service/bench/runner.cjs

@@ -0,0 +1,158 @@
+'use strict'
+
+const { performance } = require('node:perf_hooks')
+const fs = require('node:fs')
+const path = require('node:path')
+const { execSync } = require('node:child_process')
+
+const cds = require('@sap/cds')
+const cqn4sql = require('../lib/cqn4sql')
+
+// config
+const ITER = Number(process.env.ITER || 500)
+const WARMUP = Number(process.env.WARMUP || 50)
+const CSV_PATH = process.env.CSV || path.join(__dirname, 'results/results.csv')
+
+// stats in ms
+function stats(ms) {
+  // sort values ascending for percentile/median calculation
+  ms.sort((a, b) => a - b)
+
+  const n = ms.length
+
+  const min = ms[0]
+  const max = ms[n - 1]
+  const median = ms[Math.floor(n / 2)]
+  const mean = ms.reduce((s, x) => s + x, 0) / n
+
+  // 95th percentile --> 5% of runs were slower than p95
+  const p95 = ms[Math.floor(n * 0.95)]
+  // MAD (Median Absolute Deviation): measure of variability
+  const madArr = ms.map(x => Math.abs(x - median)).sort((a, b) => a - b)
+  const mad = madArr[Math.floor(n / 2)]
+
+  return { n, min, max, median, p95, mean, mad }
+}
+
+function getCommitSha() {
+  try {
+    return execSync('git rev-parse --short=12 HEAD', { cwd: path.join(__dirname, '..') })
+      .toString()
+      .trim()
+  } catch {
+    return 'unknown'
+  }
+}
+
+function fmtNum(x) {
+  return x.toFixed(3)
+}
+
+function appendCsvRow(filePath, commit, row) {
+  const line =
+    [
+      commit,
+      row.case,
+      row.n,
+      fmtNum(row.min),
+      fmtNum(row.max),
+      fmtNum(row.median),
+      fmtNum(row.p95),
+      fmtNum(row.mean),
+      fmtNum(row.mad),
+    ].join(',') + '\n'
+  fs.appendFileSync(filePath, line, 'utf8')
+}
+
+function ensureCsvHeader(filePath) {
+  const header = 'commit_sha,case,n,min_ms,max_ms,median_ms,p95_ms,mean_ms,mad_ms\n'
+  if (!fs.existsSync(filePath) || fs.statSync(filePath).size === 0) {
+    fs.mkdirSync(path.dirname(filePath), { recursive: true })
+    fs.writeFileSync(filePath, header, 'utf8')
+  }
+}
+
+function removeExistingEntriesForCommit(filePath, commit) {
+  if (!fs.existsSync(filePath)) return
+  const prefix = commit + ','
+  const lines = fs.readFileSync(filePath, 'utf8').split(/\r?\n/)
+
+  const filtered = lines.filter((line, i) => i === 0 || !line.startsWith(prefix))
+
+  fs.writeFileSync(filePath, filtered.join('\n'), 'utf8')
+}
+
+function gcSafe() {
+  if (global.gc) global.gc()
+}
+
+;(async function run() {
+  const modelDir = path.join(__dirname, 'model')
+  const model = await cds.load([modelDir]).then(cds.linked)
+
+  // discover cases
+  const casesDir = path.join(__dirname, 'cases')
+  const caseFiles = fs.readdirSync(casesDir).filter(f => /\.(cjs|js)$/.test(f))
+
+  const commit = getCommitSha()
+  // prepare CSV
+  ensureCsvHeader(CSV_PATH)
+  removeExistingEntriesForCommit(CSV_PATH, commit)
+
+  const results = []
+
+  for (const f of caseFiles) {
+    const mod = require(path.join(casesDir, f))
+    const label = mod.name || path.basename(f, path.extname(f))
+
+    if (typeof mod.setup === 'function') await mod.setup({ cqn4sql, model, cds })
+
+    // warmup
+    for (let i = 0; i < WARMUP; i++) {
+      const cqn = mod.buildInput({ model, cds })
+      cqn4sql(cqn, model)
+    }
+    gcSafe()
+
+    // timed iterations
+    const times = []
+    for (let i = 0; i < ITER; i++) {
+      const cqn = mod.buildInput({ model, cds })
+      const t0 = performance.now()
+      cqn4sql(cqn, model)
+      const t1 = performance.now()
+      times.push(t1 - t0)
+    }
+
+    if (typeof mod.teardown === 'function') await mod.teardown()
+
+    const s = stats(times)
+    const row = { case: label, ...s }
+    results.push({ commit, ...row })
+    gcSafe()
+  }
+
+  results.sort((a, b) => a.median - b.median)
+
+  console.log('case,n,min_ms,max_ms,median_ms,p95_ms,mean_ms,mad_ms')
+  for (const row of results) {
+    console.log(
+      [
+        row.case,
+        row.n,
+        fmtNum(row.min),
+        fmtNum(row.max),
+        fmtNum(row.median),
+        fmtNum(row.p95),
+        fmtNum(row.mean),
+        fmtNum(row.mad),
+      ].join(','),
+    )
+    appendCsvRow(CSV_PATH, commit, row)
+  }
+
+  console.error(`\nAppended results to ${CSV_PATH} (commit ${commit})`)
+})().catch(err => {
+  console.error(err)
+  process.exit(1)
+})