Which databases really speak the protocol they claim
Measured check by check against the original engine: PostgreSQL, MySQL, MongoDB, Elasticsearch.
Dataset 45a7361f915b, audited 23 October 2026.
✓Works the same
≠Differs
∅Refused
✕Breaks
·Not measured
✓Works the same
≠Differs
∅Refused
✕Breaks
·Not measured
PostgreSQL wire protocol20 engines, best first. Pick an engine for what differs; pick a column for its features.
Types
Engine
Score
Referencepostgres-13 to postgres-18
the original
✓Works the same, 86 of 86 checks matched
✓Works the same, 72 of 72 checks matched
✓Works the same, 60 of 60 checks matched
✓Works the same, 36 of 36 checks matched
✓Works the same, 96 of 96 checks matched
✓Works the same, 66 of 66 checks matched
✓Works the same, 96 of 96 checks matched
✓Works the same, 522 of 522 checks matched
✓Works the same, 246 of 246 checks matched
✓Works the same, 2004 of 2004 checks matched
✓Works the same, 4380 of 4380 checks matched
98.9
∅91%Refused, 11 of 12 checks matched
✓Works the same, 12 of 12 checks matched
✓Works the same, 10 of 10 checks matched
✓Works the same, 6 of 6 checks matched
✓Works the same, 16 of 16 checks matched
✓Works the same, 11 of 11 checks matched
✓Works the same, 16 of 16 checks matched
✓Works the same, 87 of 87 checks matched
✓Works the same, 41 of 41 checks matched
✓Works the same, 334 of 334 checks matched
✓Works the same, 735 of 735 checks matched
98.7
∅91%Refused, 11 of 12 checks matched
✓Works the same, 12 of 12 checks matched
✓Works the same, 10 of 10 checks matched
✓Works the same, 6 of 6 checks matched
✓Works the same, 16 of 16 checks matched
✓Works the same, 11 of 11 checks matched
✓Works the same, 16 of 16 checks matched
✓Works the same, 87 of 87 checks matched
≠97%Differs, 40 of 41 checks matched
✓Works the same, 332 of 332 checks matched
≠99%Differs, 722 of 727 checks matched
97.7
∅91%Refused, 11 of 12 checks matched
✓Works the same, 12 of 12 checks matched
✓Works the same, 10 of 10 checks matched
∅83%Refused, 5 of 6 checks matched
✓Works the same, 16 of 16 checks matched
✓Works the same, 11 of 11 checks matched
✓Works the same, 16 of 16 checks matched
≠98%Differs, 86 of 87 checks matched
✓Works the same, 41 of 41 checks matched
✓Works the same, 334 of 334 checks matched
≠99%Differs, 732 of 733 checks matched
91.3
≠75%Differs, 9 of 12 checks matched
✕91%Breaks, 11 of 12 checks matched
✕80%Breaks, 8 of 10 checks matched
≠66%Differs, 4 of 6 checks matched
✓Works the same, 16 of 16 checks matched
✓Works the same, 11 of 11 checks matched
✓Works the same, 16 of 16 checks matched
✓Works the same, 87 of 87 checks matched
✓Works the same, 41 of 41 checks matched
✓Works the same, 334 of 334 checks matched
≠99%Differs, 736 of 737 checks matched
68.2
✕46%Breaks, 7 of 15 checks matched
≠91%Differs, 11 of 12 checks matched
∅90%Refused, 9 of 10 checks matched
≠16%Differs, 1 of 6 checks matched
≠81%Differs, 13 of 16 checks matched
≠72%Differs, 8 of 11 checks matched
≠56%Differs, 9 of 16 checks matched
✕29%Breaks, 24 of 81 checks matched
≠17%Differs, 7 of 41 checks matched
≠97%Differs, 87 of 89 checks matched
✕84%Breaks, 281 of 332 checks matched
64.4
✕50%Breaks, 6 of 12 checks matched
≠66%Differs, 8 of 12 checks matched
≠50%Differs, 5 of 10 checks matched
≠0%Differs, 0 of 6 checks matched
≠56%Differs, 9 of 16 checks matched
≠72%Differs, 8 of 11 checks matched
≠25%Differs, 4 of 16 checks matched
≠60%Differs, 49 of 81 checks matched
≠29%Differs, 12 of 41 checks matched
≠90%Differs, 100 of 110 checks matched
≠82%Differs, 429 of 517 checks matched
62.7
≠75%Differs, 9 of 12 checks matched
≠75%Differs, 9 of 12 checks matched
≠40%Differs, 4 of 10 checks matched
≠33%Differs, 2 of 6 checks matched
≠56%Differs, 9 of 16 checks matched
≠36%Differs, 4 of 11 checks matched
≠31%Differs, 5 of 16 checks matched
≠28%Differs, 23 of 80 checks matched
≠29%Differs, 12 of 41 checks matched
≠91%Differs, 75 of 82 checks matched
≠79%Differs, 322 of 403 checks matched
46.6
≠71%Differs, 10 of 14 checks matched
≠75%Differs, 9 of 12 checks matched
≠60%Differs, 6 of 10 checks matched
≠0%Differs, 0 of 6 checks matched
≠75%Differs, 12 of 16 checks matched
≠72%Differs, 8 of 11 checks matched
≠12%Differs, 2 of 16 checks matched
≠52%Differs, 46 of 87 checks matched
≠17%Differs, 7 of 41 checks matched
≠91%Differs, 98 of 107 checks matched
✕12%Breaks, 84 of 698 checks matched
33.8
✕42%Breaks, 6 of 14 checks matched
≠50%Differs, 6 of 12 checks matched
≠10%Differs, 1 of 10 checks matched
≠0%Differs, 0 of 6 checks matched
≠0%Differs, 0 of 16 checks matched
≠0%Differs, 0 of 11 checks matched
≠0%Differs, 0 of 16 checks matched
≠0%Differs, 0 of 87 checks matched
≠2%Differs, 1 of 41 checks matched
≠61%Differs, 68 of 110 checks matched
✕44%Breaks, 215 of 479 checks matched
31.4
≠41%Differs, 5 of 12 checks matched
≠83%Differs, 10 of 12 checks matched
≠20%Differs, 2 of 10 checks matched
≠0%Differs, 0 of 6 checks matched
≠62%Differs, 10 of 16 checks matched
≠72%Differs, 8 of 11 checks matched
≠18%Differs, 3 of 16 checks matched
≠1%Differs, 1 of 87 checks matched
≠14%Differs, 6 of 41 checks matched
≠90%Differs, 87 of 96 checks matched
≠1%Differs, 1 of 80 checks matched
21.5
✕25%Breaks, 3 of 12 checks matched
✕25%Breaks, 3 of 12 checks matched
✕10%Breaks, 1 of 10 checks matched
≠0%Differs, 0 of 6 checks matched
≠0%Differs, 0 of 16 checks matched
≠0%Differs, 0 of 11 checks matched
≠0%Differs, 0 of 16 checks matched
≠1%Differs, 1 of 81 checks matched
≠2%Differs, 1 of 41 checks matched
≠98%Differs, 139 of 141 checks matched
✕1%Breaks, 1 of 80 checks matched
20.1
≠41%Differs, 5 of 12 checks matched
≠50%Differs, 6 of 12 checks matched
✕10%Breaks, 1 of 10 checks matched
≠0%Differs, 0 of 6 checks matched
≠37%Differs, 6 of 16 checks matched
≠18%Differs, 2 of 11 checks matched
≠0%Differs, 0 of 16 checks matched
≠0%Differs, 0 of 80 checks matched
≠4%Differs, 2 of 41 checks matched
≠82%Differs, 42 of 51 checks matched
≠0%Differs, 0 of 80 checks matched
18.1
✕25%Breaks, 3 of 12 checks matched
✕41%Breaks, 5 of 12 checks matched
≠10%Differs, 1 of 10 checks matched
≠0%Differs, 0 of 6 checks matched
≠50%Differs, 8 of 16 checks matched
≠18%Differs, 2 of 11 checks matched
≠6%Differs, 1 of 16 checks matched
≠1%Differs, 1 of 81 checks matched
≠4%Differs, 2 of 41 checks matched
≠94%Differs, 47 of 50 checks matched
✕0%Breaks, 0 of 80 checks matched
15.2
≠41%Differs, 5 of 12 checks matched
≠33%Differs, 1 of 3 checks matched
·Not measured, 0 of 2 checks matched
≠25%Differs, 1 of 4 checks matched
·Not measured
·Not measured
·Not measured
·Not measured
≠0%Differs, 0 of 4 checks matched
≠0%Differs, 0 of 2 checks matched
✕0%Breaks, 0 of 77 checks matched
13.7
✕33%Breaks, 4 of 12 checks matched
≠41%Differs, 5 of 12 checks matched
≠10%Differs, 1 of 10 checks matched
≠0%Differs, 0 of 6 checks matched
≠0%Differs, 0 of 16 checks matched
≠0%Differs, 0 of 11 checks matched
≠0%Differs, 0 of 16 checks matched
≠0%Differs, 0 of 80 checks matched
≠2%Differs, 1 of 41 checks matched
≠66%Differs, 18 of 27 checks matched
✕0%Breaks, 0 of 80 checks matched
13.3
≠50%Differs, 6 of 12 checks matched
≠16%Differs, 2 of 12 checks matched
≠0%Differs, 0 of 10 checks matched
≠0%Differs, 0 of 6 checks matched
≠0%Differs, 0 of 16 checks matched
≠0%Differs, 0 of 11 checks matched
≠0%Differs, 0 of 16 checks matched
≠0%Differs, 0 of 80 checks matched
≠2%Differs, 1 of 41 checks matched
≠58%Differs, 30 of 51 checks matched
≠1%Differs, 1 of 80 checks matched
10.5
✕33%Breaks, 4 of 12 checks matched
≠8%Differs, 1 of 12 checks matched
≠0%Differs, 0 of 10 checks matched
≠0%Differs, 0 of 6 checks matched
≠25%Differs, 4 of 16 checks matched
≠27%Differs, 3 of 11 checks matched
≠0%Differs, 0 of 16 checks matched
≠10%Differs, 8 of 79 checks matched
≠2%Differs, 1 of 41 checks matched
·Not measured
≠7%Differs, 6 of 80 checks matched
7
✕16%Breaks, 2 of 12 checks matched
≠8%Differs, 1 of 12 checks matched
≠0%Differs, 0 of 10 checks matched
≠0%Differs, 0 of 6 checks matched
≠0%Differs, 0 of 16 checks matched
≠0%Differs, 0 of 11 checks matched
≠0%Differs, 0 of 16 checks matched
≠0%Differs, 0 of 80 checks matched
≠2%Differs, 1 of 41 checks matched
≠92%Differs, 23 of 25 checks matched
≠0%Differs, 0 of 80 checks matched
4.3
✕25%Breaks, 3 of 12 checks matched
≠8%Differs, 1 of 12 checks matched
≠0%Differs, 0 of 10 checks matched
≠0%Differs, 0 of 6 checks matched
≠0%Differs, 0 of 16 checks matched
≠0%Differs, 0 of 11 checks matched
≠0%Differs, 0 of 16 checks matched
≠0%Differs, 0 of 12 checks matched
≠0%Differs, 0 of 41 checks matched
·Not measured
≠0%Differs, 0 of 80 checks matched
3.3
≠16%Differs, 2 of 12 checks matched
≠8%Differs, 1 of 12 checks matched
≠0%Differs, 0 of 10 checks matched
≠0%Differs, 0 of 6 checks matched
≠0%Differs, 0 of 16 checks matched
✕0%Breaks, 0 of 11 checks matched
≠0%Differs, 0 of 16 checks matched
·Not measured, 0 of 87 checks matched
≠2%Differs, 1 of 41 checks matched
·Not measured, 0 of 334 checks matched
·Not measured, 0 of 739 checks matched
MySQL client/server protocol14 engines, best first. Pick an engine for what differs; pick a column for its features.
Engine
Score
Referencemysql-5.7 to mysql-9
the original
✓Works the same, 60 of 60 checks matched
✓Works the same, 52 of 52 checks matched
✓Works the same, 8 of 8 checks matched
✓Works the same, 28 of 28 checks matched
✓Works the same, 380 of 380 checks matched
✓Works the same, 76 of 76 checks matched
100
✓Works the same, 15 of 15 checks matched
✓Works the same, 13 of 13 checks matched
✓Works the same, 2 of 2 checks matched
✓Works the same, 7 of 7 checks matched
✓Works the same, 95 of 95 checks matched
✓Works the same, 19 of 19 checks matched
84.7
≠36%Differs, 4 of 11 checks matched
✓Works the same, 13 of 13 checks matched
≠50%Differs, 1 of 2 checks matched
≠71%Differs, 5 of 7 checks matched
≠95%Differs, 91 of 95 checks matched
≠94%Differs, 18 of 19 checks matched
81.1
≠40%Differs, 6 of 15 checks matched
✓Works the same, 13 of 13 checks matched
≠50%Differs, 1 of 2 checks matched
≠71%Differs, 5 of 7 checks matched
≠86%Differs, 82 of 95 checks matched
≠94%Differs, 18 of 19 checks matched
59.1
≠36%Differs, 4 of 11 checks matched
✕46%Breaks, 6 of 13 checks matched
✓Works the same, 2 of 2 checks matched
≠28%Differs, 2 of 7 checks matched
≠78%Differs, 72 of 92 checks matched
✕63%Breaks, 12 of 19 checks matched
44.7
≠36%Differs, 4 of 11 checks matched
≠30%Differs, 4 of 13 checks matched
≠50%Differs, 1 of 2 checks matched
≠28%Differs, 2 of 7 checks matched
≠89%Differs, 85 of 95 checks matched
≠15%Differs, 3 of 19 checks matched
34.8
≠27%Differs, 3 of 11 checks matched
✕38%Breaks, 5 of 13 checks matched
≠0%Differs, 0 of 2 checks matched
≠28%Differs, 2 of 7 checks matched
≠70%Differs, 67 of 95 checks matched
∅5%Refused, 1 of 19 checks matched
23.3
≠27%Differs, 3 of 11 checks matched
✕23%Breaks, 3 of 13 checks matched
≠0%Differs, 0 of 2 checks matched
≠0%Differs, 0 of 7 checks matched
≠53%Differs, 51 of 95 checks matched
≠0%Differs, 0 of 19 checks matched
21.7
≠36%Differs, 4 of 11 checks matched
≠7%Differs, 1 of 13 checks matched
≠0%Differs, 0 of 2 checks matched
≠0%Differs, 0 of 7 checks matched
≠52%Differs, 50 of 95 checks matched
≠0%Differs, 0 of 19 checks matched
11.9
≠27%Differs, 3 of 11 checks matched
✕7%Breaks, 1 of 13 checks matched
≠0%Differs, 0 of 2 checks matched
≠0%Differs, 0 of 7 checks matched
≠23%Differs, 15 of 64 checks matched
≠0%Differs, 0 of 19 checks matched
11.5
≠18%Differs, 2 of 11 checks matched
≠7%Differs, 1 of 13 checks matched
≠0%Differs, 0 of 2 checks matched
≠0%Differs, 0 of 7 checks matched
≠26%Differs, 17 of 65 checks matched
≠0%Differs, 0 of 19 checks matched
6.7
≠26%Differs, 4 of 15 checks matched
≠7%Differs, 1 of 13 checks matched
≠0%Differs, 0 of 2 checks matched
≠14%Differs, 1 of 7 checks matched
≠0%Differs, 0 of 48 checks matched
≠0%Differs, 0 of 19 checks matched
2.5
≠9%Differs, 1 of 11 checks matched
✕7%Breaks, 1 of 13 checks matched
≠0%Differs, 0 of 2 checks matched
≠0%Differs, 0 of 7 checks matched
≠0%Differs, 0 of 95 checks matched
≠0%Differs, 0 of 19 checks matched
1.2
≠9%Differs, 1 of 11 checks matched
≠0%Differs, 0 of 13 checks matched
≠0%Differs, 0 of 2 checks matched
✕0%Breaks, 0 of 7 checks matched
✕0%Breaks, 0 of 85 checks matched
≠0%Differs, 0 of 19 checks matched
1.2
≠9%Differs, 1 of 11 checks matched
≠0%Differs, 0 of 13 checks matched
≠0%Differs, 0 of 2 checks matched
≠0%Differs, 0 of 7 checks matched
≠0%Differs, 0 of 48 checks matched
≠0%Differs, 0 of 19 checks matched
MongoDB wire protocol3 engines, best first. Pick an engine for what differs; pick a column for its features.
Types
Engine
Score
Referencemongodb-6.0 to mongodb-8.0
the original
✓Works the same, 93 of 93 checks matched
✓Works the same, 12 of 12 checks matched
✓Works the same, 6 of 6 checks matched
✓Works the same, 3 of 3 checks matched
✓Works the same, 18 of 18 checks matched
✓Works the same, 15 of 15 checks matched
✓Works the same, 6 of 6 checks matched
✓Works the same, 9 of 9 checks matched
✓Works the same, 9 of 9 checks matched
✓Works the same, 12 of 12 checks matched
✓Works the same, 36 of 36 checks matched
98.9
∅96%Refused, 29 of 30 checks matched
✓Works the same, 4 of 4 checks matched
✓Works the same, 2 of 2 checks matched
✓Works the same, 1 of 1 checks matched
✓Works the same, 6 of 6 checks matched
✓Works the same, 5 of 5 checks matched
✓Works the same, 2 of 2 checks matched
✓Works the same, 3 of 3 checks matched
✓Works the same, 3 of 3 checks matched
✓Works the same, 4 of 4 checks matched
✓Works the same, 12 of 12 checks matched
48.4
≠33%Differs, 10 of 30 checks matched
≠50%Differs, 2 of 4 checks matched
≠50%Differs, 1 of 2 checks matched
✓Works the same, 1 of 1 checks matched
≠83%Differs, 5 of 6 checks matched
≠80%Differs, 4 of 5 checks matched
≠50%Differs, 1 of 2 checks matched
✓Works the same, 3 of 3 checks matched
✓Works the same, 3 of 3 checks matched
≠50%Differs, 2 of 4 checks matched
≠33%Differs, 4 of 12 checks matched
48.3
≠29%Differs, 9 of 31 checks matched
≠50%Differs, 2 of 4 checks matched
≠50%Differs, 1 of 2 checks matched
∅0%Refused, 0 of 1 checks matched
≠83%Differs, 5 of 6 checks matched
≠80%Differs, 4 of 5 checks matched
≠50%Differs, 1 of 2 checks matched
✓Works the same, 3 of 3 checks matched
✓Works the same, 3 of 3 checks matched
≠50%Differs, 2 of 4 checks matched
≠41%Differs, 5 of 12 checks matched
Elasticsearch REST API6 engines, best first. Pick an engine for what differs; pick a column for its features.
Types
Engine
Score
Referenceelasticsearch-7 to elasticsearch-9
the original
✓Works the same, 21 of 21 checks matched
✓Works the same, 21 of 21 checks matched
✓Works the same, 24 of 24 checks matched
✓Works the same, 30 of 30 checks matched
✓Works the same, 30 of 30 checks matched
✓Works the same, 9 of 9 checks matched
✓Works the same, 33 of 33 checks matched
✓Works the same, 21 of 21 checks matched
✓Works the same, 21 of 21 checks matched
✓Works the same, 108 of 108 checks matched
77.9
≠57%Differs, 4 of 7 checks matched
≠71%Differs, 5 of 7 checks matched
≠75%Differs, 6 of 8 checks matched
≠90%Differs, 9 of 10 checks matched
≠70%Differs, 7 of 10 checks matched
≠66%Differs, 2 of 3 checks matched
≠63%Differs, 7 of 11 checks matched
≠57%Differs, 4 of 7 checks matched
✓Works the same, 7 of 7 checks matched
≠94%Differs, 34 of 36 checks matched
76.3
≠57%Differs, 4 of 7 checks matched
≠71%Differs, 5 of 7 checks matched
≠75%Differs, 6 of 8 checks matched
≠90%Differs, 9 of 10 checks matched
≠70%Differs, 7 of 10 checks matched
≠66%Differs, 2 of 3 checks matched
≠63%Differs, 7 of 11 checks matched
≠57%Differs, 4 of 7 checks matched
✓Works the same, 7 of 7 checks matched
≠88%Differs, 32 of 36 checks matched
69.7
≠57%Differs, 4 of 7 checks matched
≠57%Differs, 4 of 7 checks matched
≠62%Differs, 5 of 8 checks matched
≠80%Differs, 8 of 10 checks matched
≠70%Differs, 7 of 10 checks matched
≠66%Differs, 2 of 3 checks matched
≠63%Differs, 7 of 11 checks matched
≠57%Differs, 4 of 7 checks matched
≠85%Differs, 6 of 7 checks matched
≠83%Differs, 30 of 36 checks matched
4.6
≠28%Differs, 2 of 7 checks matched
≠0%Differs, 0 of 7 checks matched
≠0%Differs, 0 of 8 checks matched
·Not measured, 0 of 10 checks matched
·Not measured, 0 of 10 checks matched
·Not measured, 0 of 3 checks matched
·Not measured, 0 of 11 checks matched
·Not measured, 0 of 7 checks matched
∅0%Refused, 0 of 7 checks matched
≠2%Differs, 1 of 36 checks matched
3.7
≠28%Differs, 2 of 7 checks matched
≠0%Differs, 0 of 7 checks matched
≠0%Differs, 0 of 8 checks matched
≠0%Differs, 0 of 10 checks matched
≠0%Differs, 0 of 10 checks matched
≠0%Differs, 0 of 3 checks matched
≠0%Differs, 0 of 11 checks matched
≠0%Differs, 0 of 7 checks matched
≠0%Differs, 0 of 7 checks matched
≠0%Differs, 0 of 36 checks matched
3.7
≠28%Differs, 2 of 7 checks matched
≠0%Differs, 0 of 7 checks matched
≠0%Differs, 0 of 8 checks matched
≠0%Differs, 0 of 10 checks matched
≠0%Differs, 0 of 10 checks matched
≠0%Differs, 0 of 3 checks matched
≠0%Differs, 0 of 11 checks matched
≠0%Differs, 0 of 7 checks matched
≠0%Differs, 0 of 7 checks matched
≠0%Differs, 0 of 36 checks matched
Tier 0 is the wire contract only: frames, types and bulk load. It is not the SQL dialect, performance, durability or feature coverage. A high score means drivers and tools can talk to the engine as they do to the reference; it does not mean your queries behave the same.All caveats and how scores are counted