Live pushdown to DuckDB, query by query in Vue

<link rel="stylesheet" href="https://cdn.latticegrid.dev/lattice-grid@1.108.0/lattice-grid.min.css">
<style>
  #grid > div { height: 560px; }
</style>
<div id="app"></div>

<script type="module">
  import * as Vue from 'https://esm.sh/vue@3/dist/vue.esm-browser.prod.js';
  import * as lattice from 'https://cdn.latticegrid.dev/lattice-grid@1.108.0/lattice-grid.esm.min.js';
  import createLatticeGrid from 'https://cdn.latticegrid.dev/lattice-grid@1.108.0/modules/vue.esm.min.js';
  import * as duckdb from 'https://cdn.jsdelivr.net/npm/@duckdb/duckdb-wasm@1.29.0/+esm';

  const { createGrid, duckdbAdapter, createPushdownSource } = lattice;
  const LatticeGrid = createLatticeGrid({ vue: Vue, createGrid });

  // Lattice ships no engine. The page starts DuckDB-Wasm itself and hands the
  // adapter a live connection; the grid loads none of it, so the bundle is the
  // same size whether this is used or not.
  const bundle = await duckdb.selectBundle(duckdb.getJsDelivrBundles());
  const worker = await duckdb.createWorker(bundle.mainWorker);
  const db = new duckdb.AsyncDuckDB(new duckdb.ConsoleLogger(duckdb.LogLevel.ERROR), worker);
  await db.instantiate(bundle.mainModule, bundle.pthreadWorker);
  const connection = await db.connect();

  // from is any SQL table expression. read_parquet streams the file, so a host
  // that honours range requests lets DuckDB read only the bytes a query touches.
  const adapter = duckdbAdapter({
    connection,
    from: "read_parquet('/demo-data/readings.parquet')",
  });
  const source = createPushdownSource({
    adapter,
    compute: lattice,   // the grid finishes anything SQL could not express
    pageSize: 200,      // only the visible window comes back, per interaction
  });

  // Wrap execute to show the statement DuckDB ran and how long it took.
  const inner = adapter.execute.bind(adapter);
  adapter.execute = async (query, request) => {
    const started = performance.now();
    const result = await inner(query, request);
    const ms = Math.round(performance.now() - started);
    const f = adapter.sqlFor(query);
    const out = document.getElementById('sql');
    if (out) out.textContent = f.sql + '\n-- ' + ms + ' ms, ' + result.rows.length + ' of ' + (result.total ?? '?') + ' rows';
    return result;
  };

  Vue.createApp({
    components: { LatticeGrid },
    data() {
      return {
        config: {
          rowKey: 'reading_id',
          toolPanel: { side: 'left', panels: ['filters', 'columns'] },
          columns: [
            { field: 'reading_id', title: '#', type: 'number', layout: { width: 110 } },
            { field: 'plant', title: 'Plant', filter: { type: 'set' } },
            { field: 'line', title: 'Line', filter: { type: 'set' } },
            { field: 'product', title: 'Product' },
            { field: 'bore_mm', title: 'Bore', type: 'millimetres',
              spec: { lower: 9.95, upper: 10.05, target: 10 } },
            { field: 'cycle_seconds', title: 'Cycle', type: 'seconds' },
            { field: 'in_spec', title: 'In spec', type: 'boolean' },
            { field: 'taken_at', title: 'Taken', type: 'dateString' },
          ],
          source,   // a hundred thousand rows; DuckDB answers each filter and sort in SQL
        },
      };
    },
    template: `
      <div id="grid"><lattice-grid v-bind="config" /></div>
      <pre id="sql" style="margin-top: 12px"></pre>
    `,
  }).mount('#app');
</script>