How to fix Firestore: Query exceeds maximum 30 disjunctions in Firebase

// Problematic query with too many OR conditions
const query = db.collection('products')
  .where('category', 'in', [/* array with >30 items */]);

// OR multiple where clauses
const query = db.collection('users')
  .where('status', '==', 'active')
  .where('age', '>', 18)
  .where('country', 'in', [/* large array */]);

// Split array into chunks of 30 or fewer
function chunkArray(array, chunkSize) {
  const chunks = [];
  for (let i = 0; i < array.length; i += chunkSize) {
    chunks.push(array.slice(i, i + chunkSize));
  }
  return chunks;
}

// Execute multiple queries
async function queryWithLargeInArray(items) {
  const chunks = chunkArray(items, 30);
  const promises = chunks.map(chunk => 
    db.collection('products')
      .where('id', 'in', chunk)
      .get()
  );
  
  const results = await Promise.all(promises);
  // Combine results
  return results.flatMap(snapshot => snapshot.docs);
}

// Instead of many OR conditions:
// .where('status', '==', 'pending')
// .where('status', '==', 'processing')
// .where('status', '==', 'shipped')

// Use array-contains with a statuses field
await db.collection('orders')
  .where('statuses', 'array-contains', 'active')
  .get();

// Or store active statuses in a separate array field

// Paginate through results
async function getPaginatedResults(filters, pageSize = 20) {
  let query = db.collection('items');
  
  // Apply filters in batches
  for (const filter of filters.slice(0, 30)) {
    query = query.where(filter.field, filter.operator, filter.value);
  }
  
  const snapshot = await query.limit(pageSize).get();
  return snapshot.docs;
}

// Process remaining filters in subsequent pages if needed

// Collection group query with limited disjunctions
const query = db.collectionGroup('items')
  .where('category', 'in', [/* max 30 items */])
  .where('active', '==', true);

// Combine with client-side filtering for additional criteria
const snapshot = await query.get();
const filtered = snapshot.docs.filter(doc => 
  // Additional client-side filtering
  doc.data().price > 100 && doc.data().inStock
);

// Instead of querying across many fields
// Store a tags array for efficient querying
{
  title: "Product",
  tags: ["electronics", "sale", "featured", "in-stock"],
  // ... other fields
}

// Query becomes simpler
await db.collection('products')
  .where('tags', 'array-contains-any', [/* up to 10 items */])
  .get();