Search Views

run_demos.js

// mongosh $MONGODB_URI run_demos.js

array_size_demo = {
  description: "Enriching the index with the size of an array.",
  docs: [
    {
        _id: 1,
        values: [1,2,3,4]
    },
    {
        _id: 2,
        values: [1,2,3,4,5]
    }
  ],
  view_pipeline: [
    {
      $addFields: {
        num_values: { $size: "$values" }
      }
    }
  ],
  search_pipeline: [
    {
      $search: {
        index: "view_index",
        equals: {
          path: "num_values",
          value: 4
        }
      }
    }
  ]
}

partial_demo = {
  description: "Indexing only non-archived documents.",
  docs: [
    {
        _id: 1,
    },
    {
        _id: 2,
        archived: true
    }
  ],
  view_pipeline: [
    {
      $match: {
        $expr: {
          $ne: ["$archived", true]
        }
      }
    }
  ],
  search_pipeline: [
    {
      $search: {
        index: "view_index",
        exists: {
          path: "_id"
        }
      }
    }
  ]
}

unsearchable_demo = {
  description: "Making a field unsearchable.",
  docs: [
    {
        _id: 1,
        public: "this is public info",
        private: "this is private info"
    }
  ],
  view_pipeline: [
    {
	    $set: {
  		  private: "$$REMOVE"
      }
    }
  ],
  search_pipeline: [
    {
      $search: {
        index: "view_index",
        text: {
          query: "private",
          path: { wildcard: "*" },
        }
      }
    }
  ]
}

// flatten_attributes_demo = {
//   description: "Flattening an array of key-value pairs to make them searchable.",
//   docs: [
//     {
//         _id: 1,
//         extras: [
//           { key: "color", value: "red" },
//           { key: "shape", value: "square" }
//         ]
//     }
//   ],
//   view_pipeline: [
//     {
//       $addFields: {
//         extras: {
//           $arrayToObject: {
//             $map: {
//               input: "$extras",
//               as: "item",
//               in: [ "$$item.key", "$$item.value" ]
//             }
//           }
//         }
//       }
//     }
//   ],
//   search_pipeline: [
//     {
//       $search: {
//         index: "view_index",
//         text: {
//           query: "red",
//           path: "extras.color"
//         }
//       }
//     }
//   ]
// }


// ...                 $arrayToObject: {
// ...                     $map: {
// ...                         input: "$extras",
// ...                         as: "item",
// ...                         in: [ "$$item.key", "$$item.value" ]
// ...                     }
// ...                 }
// ...             }
// ...         }
// ...     }
// ... ]

demos = {
  'array_size': array_size_demo,
  'partial': partial_demo,
  'unsearchable': unsearchable_demo,
  // 'flatten_attributes': flatten_attributes_demo
}

function run_demo(demo_name) {
  demo = demos[demo_name];
  db = db.getSiblingDB('view_demo_' + demo_name);

  console.log('\nCreating fresh environment...');
  db.view.dropSearchIndex('view_index');
  db.view.drop();
  db.docs.deleteMany({});
  console.log('  - environment ready');

  console.log('\nInserting some docs:');
  result = db.docs.insertMany(demo.docs);
  console.log(db.docs.find({}).toArray());

  if (demo_name == 'array_size') {
    // only this demo shows winning plan
    match_stage = { $match: { values: { $size: 4 } } }
    result = db.docs.aggregate([match_stage]).explain();

    // `winningPlan` is COLLSCAN
    console.log(JSON.stringify(match_stage) + " winningPlan: " +result["queryPlanner"]["winningPlan"]["stage"]);
  }

  console.log('\nCreating enrichment view...')
  view_pipeline = demo.view_pipeline

  db.createView(
    "view",
    "docs",
    view_pipeline
  )
  console.log('View created: ')
  console.log(view_pipeline)

  console.log('\nDocs from view:')
  console.log(db.view.find({}).toArray());

  db.view.createSearchIndex(
    "view_index",
    {
      "mappings": {
        "dynamic": true
      }
    }
  )
  console.log('\nSearch index created. Polling until READY...')

  index_status = "TBD"
  while (index_status != "READY") {
    sleep(3000)
    indexes = db.view.getSearchIndexes({name: "view_index"})
    index_status = indexes[0]["status"]
  }
  console.log('Index is READY')

  search_pipeline = demo.search_pipeline

  console.log('\nSearch pipeline:')
  console.log(search_pipeline)

  console.log('\nSearch results:')
  results = db.view.aggregate(search_pipeline).toArray();
  console.log(results);
}

demo_names = ['array_size', 'partial', 'unsearchable']

for (demo_name of demo_names) {
  console.log('\n\n===============================');
  console.log('Demo: ' + demo_name);  
  console.log(demos[demo_name].description);
  console.log('===============================\n');
  
  run_demo(demo_name);
}