omnigraph-engine 0.2.2

Runtime engine for the Omnigraph graph database.
Documentation
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
mod helpers;

use arrow_array::{Array, Int32Array};
use helpers::*;
use omnigraph::db::Omnigraph;
use omnigraph_compiler::ir::ParamMap;

// ─── Inline queries for point-in-time tests ─────────────────────────────────

const ALL_PERSONS_QUERY: &str = r#"
query all_persons() {
    match {
        $p: Person
    }
    return { $p.name, $p.age }
    order { $p.name asc }
}
"#;

const FRIENDS_QUERY: &str = r#"
query friends_of($name: String) {
    match {
        $p: Person { name: $name }
        $p knows $f
    }
    return { $f.name }
    order { $f.name asc }
}
"#;

const UNEMPLOYED_QUERY: &str = r#"
query unemployed() {
    match {
        $p: Person
        not { $p worksAt $_ }
    }
    return { $p.name }
    order { $p.name asc }
}
"#;

const FILTERED_QUERY: &str = r#"
query older_than($min_age: I32) {
    match {
        $p: Person
        $p.age > $min_age
    }
    return { $p.name, $p.age }
    order { $p.name asc }
}
"#;

const GET_PERSON_QUERY: &str = r#"
query get_person($name: String) {
    match {
        $p: Person { name: $name }
    }
    return { $p.name, $p.age }
}
"#;

// ─── Morphological matrix ───────────────────────────────────────────────────
//
// Dimensions:
//   Query type:   Tabular | Traversal | Negation (AntiJoin) | Filtered | Aggregation
//   Mutation:     Insert  | Update    | Delete node         | Delete edge
//   Branch:       Main    | Named branch
//   Result shape: Empty→non-empty | Non-empty→empty | Count changes | Value changes
//
// Existing coverage (4 tests):
//   Tabular  × Insert  × Main  (returns_historical_data)
//   Traversal × Insert × Main  (traversal_uses_historical_graph_index)
//   Tabular  × Update  × Main  (multiple_versions_sees_correct_state)
//   Error case                  (snapshot_at_version_fails_for_nonexistent_version)
//
// New coverage (9 tests below):
//   Tabular    × Delete node  × Main   → non-empty becomes smaller
//   Traversal  × Delete edge  × Main   → edge disappears from historical
//   Negation   × Insert edge  × Main   → anti-join result shrinks after insert
//   Negation   × Delete edge  × Main   → anti-join result grows after delete
//   Filtered   × Update       × Main   → entity enters/exits filter after age change
//   Multi-hop  × Insert(n+e)  × Main   → friends-of-friends grows after new path
//   Traversal  × Delete node  × Main   → cascade removes edges from traversal
//   Tabular    × Insert       × Branch → branch isolation for point-in-time
//   Tabular    × Multi-step   × Main   → 4-version chain: insert, update, delete

// ─── Original tests ────────────────────────────────────────────────────────

#[tokio::test]
async fn run_query_at_returns_historical_data() {
    let dir = tempfile::tempdir().unwrap();
    let mut db = init_and_load(&dir).await;
    let v_before = version_main(&db).await.unwrap();

    mutate_main(
        &mut db,
        MUTATION_QUERIES,
        "insert_person",
        &mixed_params(&[("$name", "Eve")], &[("$age", 22)]),
    )
    .await
    .unwrap();

    let historical = db
        .run_query_at(v_before, ALL_PERSONS_QUERY, "all_persons", &ParamMap::new())
        .await
        .unwrap();
    let current = query_main(&mut db, ALL_PERSONS_QUERY, "all_persons", &ParamMap::new())
        .await
        .unwrap();

    assert_eq!(historical.num_rows(), 4, "historical should have 4 persons");
    assert_eq!(current.num_rows(), 5, "current should have 5 persons");

    let historical_names = collect_column_strings(historical.batches(), "p.name");
    assert!(!historical_names.contains(&"Eve".to_string()));

    let current_names = collect_column_strings(current.batches(), "p.name");
    assert!(current_names.contains(&"Eve".to_string()));
}

#[tokio::test]
async fn run_query_at_traversal_uses_historical_graph_index() {
    let dir = tempfile::tempdir().unwrap();
    let mut db = init_and_load(&dir).await;
    let v_before = version_main(&db).await.unwrap();

    mutate_main(
        &mut db,
        MUTATION_QUERIES,
        "insert_person",
        &mixed_params(&[("$name", "Eve")], &[("$age", 22)]),
    )
    .await
    .unwrap();
    mutate_main(
        &mut db,
        MUTATION_QUERIES,
        "add_friend",
        &params(&[("$from", "Eve"), ("$to", "Alice")]),
    )
    .await
    .unwrap();

    let historical = db
        .run_query_at(
            v_before,
            FRIENDS_QUERY,
            "friends_of",
            &params(&[("$name", "Alice")]),
        )
        .await
        .unwrap();
    let current = query_main(
        &mut db,
        FRIENDS_QUERY,
        "friends_of",
        &params(&[("$name", "Eve")]),
    )
    .await
    .unwrap();

    assert_eq!(historical.num_rows(), 2);
    let hist_names = collect_column_strings(historical.batches(), "f.name");
    assert!(hist_names.contains(&"Bob".to_string()));
    assert!(hist_names.contains(&"Charlie".to_string()));

    assert_eq!(current.num_rows(), 1);
    let cur_names = collect_column_strings(current.batches(), "f.name");
    assert!(cur_names.contains(&"Alice".to_string()));
}

#[tokio::test]
async fn snapshot_at_version_fails_for_nonexistent_version() {
    let dir = tempfile::tempdir().unwrap();
    let db = init_and_load(&dir).await;

    let result = db.snapshot_at_version(99999).await;
    assert!(result.is_err(), "non-existent version should return error");
}

#[tokio::test]
async fn run_query_at_multiple_versions_sees_correct_state() {
    let dir = tempfile::tempdir().unwrap();
    let mut db = init_and_load(&dir).await;
    let v1 = version_main(&db).await.unwrap();

    mutate_main(
        &mut db,
        MUTATION_QUERIES,
        "set_age",
        &mixed_params(&[("$name", "Alice")], &[("$age", 99)]),
    )
    .await
    .unwrap();
    let v2 = version_main(&db).await.unwrap();

    mutate_main(
        &mut db,
        MUTATION_QUERIES,
        "insert_person",
        &mixed_params(&[("$name", "Frank")], &[("$age", 40)]),
    )
    .await
    .unwrap();

    let at_v1 = db
        .run_query_at(v1, ALL_PERSONS_QUERY, "all_persons", &ParamMap::new())
        .await
        .unwrap();
    assert_eq!(at_v1.num_rows(), 4, "v1 should have 4 persons");
    let v1_names = collect_column_strings(at_v1.batches(), "p.name");
    assert!(!v1_names.contains(&"Frank".to_string()));

    let at_v2 = db
        .run_query_at(v2, ALL_PERSONS_QUERY, "all_persons", &ParamMap::new())
        .await
        .unwrap();
    assert_eq!(at_v2.num_rows(), 4, "v2 should have 4 persons");
    let v2_names = collect_column_strings(at_v2.batches(), "p.name");
    assert!(!v2_names.contains(&"Frank".to_string()));

    let current = query_main(&mut db, ALL_PERSONS_QUERY, "all_persons", &ParamMap::new())
        .await
        .unwrap();
    assert_eq!(current.num_rows(), 5, "current should have 5 persons");
    let cur_names = collect_column_strings(current.batches(), "p.name");
    assert!(cur_names.contains(&"Frank".to_string()));
}

// ─── Tabular × Delete node ─────────────────────────────────────────────────

#[tokio::test]
async fn tabular_delete_node_invisible_at_historical_version() {
    let dir = tempfile::tempdir().unwrap();
    let mut db = init_and_load(&dir).await;
    // Fixture: Alice, Bob, Charlie, Diana
    let v_before = version_main(&db).await.unwrap();

    mutate_main(
        &mut db,
        MUTATION_QUERIES,
        "remove_person",
        &params(&[("$name", "Charlie")]),
    )
    .await
    .unwrap();

    // Historical: Charlie still exists
    let historical = db
        .run_query_at(v_before, ALL_PERSONS_QUERY, "all_persons", &ParamMap::new())
        .await
        .unwrap();
    let hist_names = collect_column_strings(historical.batches(), "p.name");
    assert_eq!(historical.num_rows(), 4);
    assert!(hist_names.contains(&"Charlie".to_string()));

    // Current: Charlie is gone
    let current = query_main(&mut db, ALL_PERSONS_QUERY, "all_persons", &ParamMap::new())
        .await
        .unwrap();
    let cur_names = collect_column_strings(current.batches(), "p.name");
    assert_eq!(current.num_rows(), 3);
    assert!(!cur_names.contains(&"Charlie".to_string()));
}

// ─── Traversal × Delete edge ───────────────────────────────────────────────

#[tokio::test]
async fn traversal_delete_edge_invisible_at_historical_version() {
    let dir = tempfile::tempdir().unwrap();
    let mut db = init_and_load(&dir).await;
    // Fixture: Alice knows Bob, Alice knows Charlie
    let v_before = version_main(&db).await.unwrap();

    // Remove all Knows edges FROM Alice
    mutate_main(
        &mut db,
        MUTATION_QUERIES,
        "remove_friendship",
        &params(&[("$from", "Alice")]),
    )
    .await
    .unwrap();

    // Historical traversal: Alice's friends at v_before = Bob, Charlie
    let historical = db
        .run_query_at(
            v_before,
            FRIENDS_QUERY,
            "friends_of",
            &params(&[("$name", "Alice")]),
        )
        .await
        .unwrap();
    assert_eq!(historical.num_rows(), 2);
    let hist_names = collect_column_strings(historical.batches(), "f.name");
    assert!(hist_names.contains(&"Bob".to_string()));
    assert!(hist_names.contains(&"Charlie".to_string()));

    // Current: Alice has no friends (edges deleted)
    let current = query_main(
        &mut db,
        FRIENDS_QUERY,
        "friends_of",
        &params(&[("$name", "Alice")]),
    )
    .await
    .unwrap();
    assert_eq!(
        current.num_rows(),
        0,
        "Alice should have no friends after edge deletion"
    );
}

// ─── Negation (AntiJoin) × Insert ──────────────────────────────────────────

#[tokio::test]
async fn negation_insert_shrinks_antijoin_result() {
    let dir = tempfile::tempdir().unwrap();
    let mut db = init_and_load(&dir).await;
    // Fixture: Alice worksAt Acme, Bob worksAt Globex
    // Unemployed: Charlie, Diana
    let v_before = version_main(&db).await.unwrap();

    // Give Charlie a job
    mutate_main(
        &mut db,
        r#"
query hire($from: String, $to: String) {
    insert WorksAt { from: $from, to: $to }
}
"#,
        "hire",
        &params(&[("$from", "Charlie"), ("$to", "Acme")]),
    )
    .await
    .unwrap();

    // Historical: Charlie and Diana were unemployed
    let historical = db
        .run_query_at(v_before, UNEMPLOYED_QUERY, "unemployed", &ParamMap::new())
        .await
        .unwrap();
    let hist_names = collect_column_strings(historical.batches(), "p.name");
    assert_eq!(historical.num_rows(), 2);
    assert!(hist_names.contains(&"Charlie".to_string()));
    assert!(hist_names.contains(&"Diana".to_string()));

    // Current: only Diana is unemployed
    let current = query_main(&mut db, UNEMPLOYED_QUERY, "unemployed", &ParamMap::new())
        .await
        .unwrap();
    let cur_names = collect_column_strings(current.batches(), "p.name");
    assert_eq!(current.num_rows(), 1);
    assert!(cur_names.contains(&"Diana".to_string()));
    assert!(!cur_names.contains(&"Charlie".to_string()));
}

// ─── Negation (AntiJoin) × Delete edge ─────────────────────────────────────

#[tokio::test]
async fn negation_delete_edge_grows_antijoin_result() {
    let dir = tempfile::tempdir().unwrap();
    let mut db = init_and_load(&dir).await;
    // Fixture: Alice worksAt Acme, Bob worksAt Globex
    // Unemployed at start: Charlie, Diana
    let v_before = version_main(&db).await.unwrap();

    // Fire Alice (delete WorksAt edge)
    mutate_main(
        &mut db,
        r#"
query fire($from: String) {
    delete WorksAt where from = $from
}
"#,
        "fire",
        &params(&[("$from", "Alice")]),
    )
    .await
    .unwrap();

    // Historical: 2 unemployed (Charlie, Diana)
    let historical = db
        .run_query_at(v_before, UNEMPLOYED_QUERY, "unemployed", &ParamMap::new())
        .await
        .unwrap();
    assert_eq!(historical.num_rows(), 2);
    let hist_names = collect_column_strings(historical.batches(), "p.name");
    assert!(!hist_names.contains(&"Alice".to_string()));

    // Current: 3 unemployed (Alice, Charlie, Diana)
    let current = query_main(&mut db, UNEMPLOYED_QUERY, "unemployed", &ParamMap::new())
        .await
        .unwrap();
    assert_eq!(current.num_rows(), 3);
    let cur_names = collect_column_strings(current.batches(), "p.name");
    assert!(cur_names.contains(&"Alice".to_string()));
}

// ─── Filtered × Update (value enters/exits filter) ─────────────────────────

#[tokio::test]
async fn filtered_update_entity_crosses_filter_boundary() {
    let dir = tempfile::tempdir().unwrap();
    let mut db = init_and_load(&dir).await;
    // Fixture: Alice(30), Bob(25), Charlie(35), Diana(28)
    // older_than(30): Charlie(35) only
    let v_before = version_main(&db).await.unwrap();

    // Update Bob's age from 25 to 40 → enters the filter
    mutate_main(
        &mut db,
        MUTATION_QUERIES,
        "set_age",
        &mixed_params(&[("$name", "Bob")], &[("$age", 40)]),
    )
    .await
    .unwrap();

    // Historical: only Charlie is older than 30
    let historical = db
        .run_query_at(
            v_before,
            FILTERED_QUERY,
            "older_than",
            &int_params(&[("$min_age", 30)]),
        )
        .await
        .unwrap();
    assert_eq!(historical.num_rows(), 1);
    let hist_names = collect_column_strings(historical.batches(), "p.name");
    assert_eq!(hist_names, vec!["Charlie"]);

    // Current: Bob(40) and Charlie(35) are older than 30
    let current = query_main(
        &mut db,
        FILTERED_QUERY,
        "older_than",
        &int_params(&[("$min_age", 30)]),
    )
    .await
    .unwrap();
    assert_eq!(current.num_rows(), 2);
    let cur_names = collect_column_strings(current.batches(), "p.name");
    assert!(cur_names.contains(&"Bob".to_string()));
    assert!(cur_names.contains(&"Charlie".to_string()));
}

// ─── Multi-hop traversal × Insert ──────────────────────────────────────────

#[tokio::test]
async fn multi_hop_traversal_historical_version() {
    let dir = tempfile::tempdir().unwrap();
    let mut db = init_and_load(&dir).await;
    // Fixture: Alice→Bob, Alice→Charlie, Bob→Diana
    // friends_of_friends(Alice) = Diana (Alice→Bob→Diana)
    let v_before = version_main(&db).await.unwrap();

    // Insert Eve and edge: Charlie→Eve
    // Now friends_of_friends(Alice) = Diana + Eve (Alice→Charlie→Eve)
    mutate_main(
        &mut db,
        MUTATION_QUERIES,
        "insert_person",
        &mixed_params(&[("$name", "Eve")], &[("$age", 22)]),
    )
    .await
    .unwrap();
    mutate_main(
        &mut db,
        MUTATION_QUERIES,
        "add_friend",
        &params(&[("$from", "Charlie"), ("$to", "Eve")]),
    )
    .await
    .unwrap();

    let fof_query = r#"
query fof($name: String) {
    match {
        $p: Person { name: $name }
        $p knows $mid
        $mid knows $f
    }
    return { $f.name }
    order { $f.name asc }
}
"#;

    // Historical: friends-of-friends of Alice = Diana only
    let historical = db
        .run_query_at(v_before, fof_query, "fof", &params(&[("$name", "Alice")]))
        .await
        .unwrap();
    assert_eq!(historical.num_rows(), 1);
    let hist_names = collect_column_strings(historical.batches(), "f.name");
    assert_eq!(hist_names, vec!["Diana"]);

    // Current: friends-of-friends of Alice = Diana + Eve
    let current = query_main(&mut db, fof_query, "fof", &params(&[("$name", "Alice")]))
        .await
        .unwrap();
    assert_eq!(current.num_rows(), 2);
    let cur_names = collect_column_strings(current.batches(), "f.name");
    assert!(cur_names.contains(&"Diana".to_string()));
    assert!(cur_names.contains(&"Eve".to_string()));
}

// ─── Traversal × Delete node (cascade removes edges) ───────────────────────

#[tokio::test]
async fn traversal_delete_node_cascade_removes_edges() {
    let dir = tempfile::tempdir().unwrap();
    let mut db = init_and_load(&dir).await;
    // Fixture: Alice knows Bob, Alice knows Charlie, Bob knows Diana
    let v_before = version_main(&db).await.unwrap();

    // Delete Bob → cascades to Knows edges involving Bob
    mutate_main(
        &mut db,
        MUTATION_QUERIES,
        "remove_person",
        &params(&[("$name", "Bob")]),
    )
    .await
    .unwrap();

    // Historical: Alice's friends = Bob, Charlie
    let historical = db
        .run_query_at(
            v_before,
            FRIENDS_QUERY,
            "friends_of",
            &params(&[("$name", "Alice")]),
        )
        .await
        .unwrap();
    assert_eq!(historical.num_rows(), 2);
    let hist_names = collect_column_strings(historical.batches(), "f.name");
    assert!(hist_names.contains(&"Bob".to_string()));
    assert!(hist_names.contains(&"Charlie".to_string()));

    // Current: Alice's friends = Charlie only (Bob was deleted, edge cascaded)
    let current = query_main(
        &mut db,
        FRIENDS_QUERY,
        "friends_of",
        &params(&[("$name", "Alice")]),
    )
    .await
    .unwrap();
    assert_eq!(current.num_rows(), 1);
    let cur_names = collect_column_strings(current.batches(), "f.name");
    assert_eq!(cur_names, vec!["Charlie"]);
}

// ─── Branch isolation for point-in-time ────────────────────────────────────

#[tokio::test]
async fn branch_point_in_time_isolated_from_main() {
    let dir = tempfile::tempdir().unwrap();
    let uri = dir.path().to_str().unwrap();
    let mut main = init_and_load(&dir).await;

    main.branch_create("feature").await.unwrap();
    let v_main_before = version_main(&main).await.unwrap();

    // Insert Eve on main
    mutate_main(
        &mut main,
        MUTATION_QUERIES,
        "insert_person",
        &mixed_params(&[("$name", "Eve")], &[("$age", 22)]),
    )
    .await
    .unwrap();

    // Insert Frank on feature branch
    let mut feature = Omnigraph::open(uri).await.unwrap();
    mutate_branch(
        &mut feature,
        "feature",
        MUTATION_QUERIES,
        "insert_person",
        &mixed_params(&[("$name", "Frank")], &[("$age", 33)]),
    )
    .await
    .unwrap();

    // Historical main at v_main_before: 4 persons, no Eve, no Frank
    let hist_main = main
        .run_query_at(
            v_main_before,
            ALL_PERSONS_QUERY,
            "all_persons",
            &ParamMap::new(),
        )
        .await
        .unwrap();
    assert_eq!(hist_main.num_rows(), 4);
    let hist_names = collect_column_strings(hist_main.batches(), "p.name");
    assert!(!hist_names.contains(&"Eve".to_string()));
    assert!(!hist_names.contains(&"Frank".to_string()));

    // Current main: 5 persons (Eve present, Frank not visible on main)
    let cur_main = query_main(
        &mut main,
        ALL_PERSONS_QUERY,
        "all_persons",
        &ParamMap::new(),
    )
    .await
    .unwrap();
    assert_eq!(cur_main.num_rows(), 5);
    let cur_names = collect_column_strings(cur_main.batches(), "p.name");
    assert!(cur_names.contains(&"Eve".to_string()));
    assert!(!cur_names.contains(&"Frank".to_string()));

    // Feature branch: 5 persons (Frank present, Eve not visible on feature)
    let cur_feature = query_branch(
        &mut feature,
        "feature",
        ALL_PERSONS_QUERY,
        "all_persons",
        &ParamMap::new(),
    )
    .await
    .unwrap();
    assert_eq!(cur_feature.num_rows(), 5);
    let feat_names = collect_column_strings(cur_feature.batches(), "p.name");
    assert!(feat_names.contains(&"Frank".to_string()));
    assert!(!feat_names.contains(&"Eve".to_string()));
}

// ─── Multi-step version chain: insert → update → delete ────────────────────

#[tokio::test]
async fn four_version_chain_insert_update_delete() {
    let dir = tempfile::tempdir().unwrap();
    let mut db = init_and_load(&dir).await;

    // v1: baseline (Alice=30, Bob=25, Charlie=35, Diana=28)
    let v1 = version_main(&db).await.unwrap();

    // v2: insert Eve(22)
    mutate_main(
        &mut db,
        MUTATION_QUERIES,
        "insert_person",
        &mixed_params(&[("$name", "Eve")], &[("$age", 22)]),
    )
    .await
    .unwrap();
    let v2 = version_main(&db).await.unwrap();

    // v3: update Eve's age to 50
    mutate_main(
        &mut db,
        MUTATION_QUERIES,
        "set_age",
        &mixed_params(&[("$name", "Eve")], &[("$age", 50)]),
    )
    .await
    .unwrap();
    let v3 = version_main(&db).await.unwrap();

    // v4: delete Eve
    mutate_main(
        &mut db,
        MUTATION_QUERIES,
        "remove_person",
        &params(&[("$name", "Eve")]),
    )
    .await
    .unwrap();

    // v1: no Eve, 4 persons
    let at_v1 = db
        .run_query_at(v1, ALL_PERSONS_QUERY, "all_persons", &ParamMap::new())
        .await
        .unwrap();
    assert_eq!(at_v1.num_rows(), 4);
    let v1_names = collect_column_strings(at_v1.batches(), "p.name");
    assert!(!v1_names.contains(&"Eve".to_string()));

    // v2: Eve exists with age 22, 5 persons
    let at_v2 = db
        .run_query_at(
            v2,
            GET_PERSON_QUERY,
            "get_person",
            &params(&[("$name", "Eve")]),
        )
        .await
        .unwrap();
    assert_eq!(at_v2.num_rows(), 1);
    let v2_batch = at_v2.concat_batches().unwrap();
    let v2_ages = v2_batch
        .column_by_name("p.age")
        .unwrap()
        .as_any()
        .downcast_ref::<Int32Array>()
        .unwrap();
    assert_eq!(v2_ages.value(0), 22);

    // v3: Eve exists with age 50
    let at_v3 = db
        .run_query_at(
            v3,
            GET_PERSON_QUERY,
            "get_person",
            &params(&[("$name", "Eve")]),
        )
        .await
        .unwrap();
    assert_eq!(at_v3.num_rows(), 1);
    let v3_batch = at_v3.concat_batches().unwrap();
    let v3_ages = v3_batch
        .column_by_name("p.age")
        .unwrap()
        .as_any()
        .downcast_ref::<Int32Array>()
        .unwrap();
    assert_eq!(v3_ages.value(0), 50);

    // v4 (current): Eve is gone, back to 4
    let current = query_main(&mut db, ALL_PERSONS_QUERY, "all_persons", &ParamMap::new())
        .await
        .unwrap();
    assert_eq!(current.num_rows(), 4);
    let cur_names = collect_column_strings(current.batches(), "p.name");
    assert!(!cur_names.contains(&"Eve".to_string()));
}