MongoDB vs PostgreSQL
Fourteen of fourteen models named MongoDB first on the direct prompt; zero named PostgreSQL. MongoDB was named by fourteen of the fourteen models and PostgreSQL by nine and MongoDB carries 82 labels and PostgreSQL 11, so the shares are not directly comparable.
Named in four categories this edition.
Named in six categories this edition.
Share is the count of first choices across the direct, paraphrase, budget and scale prompts over all fourteen models, for a mid-market B2B company; rank is within the category; every quote names the model and the prompt it came from. Both figures come from the nosql databases page.
By framing
MongoDBFirst choices, of fourteen modelsPostgreSQL
Across every category in the October 2026 Edition, MongoDB and PostgreSQL were named in the same answer forty-nine times, of the 236 answers naming MongoDB and the 106 naming PostgreSQL. In those answers PostgreSQL took the first choice seven times and MongoDB twenty-six.
Every model, every framing
| Model | Direct | Paraphrase | Comparative | Budget-constrained | Scale-constrained | Negative |
|---|---|---|---|---|---|---|
| Claude Haiku 4.5 | | | | | ||
| GPT-5.4 mini | | | | | ||
| Gemini 3.5 Flash | | | | | | |
| Perplexity Sonar | | | | | ||
| Grok 4.1 Fast | | | | | | |
| Mistral Small | | | | | | |
| DeepSeek V4 Flash | | | | | | |
| Llama 4 Maverick | | | ||||
| Qwen 3.7 Flash | | | | | | |
| Kimi K2 | | | | | | |
| GLM 4.7 FlashX | | | | | ||
| MiniMax M2.5 | | | | | ||
| GPT-6 Luna | | | | | | |
| Muse Glimmer 30B | | | | | | |
MongoDB PostgreSQL first choice named as an alternative argued againstblank: not namedEach cell is one answer, MongoDB on the left and PostgreSQL on the right.The direct prompt
MongoDB first, PostgreSQL an alternative
14 of 14 modelsPostgreSQL was named in the answer but not as the choice, or not at all.Bold names in an answer are the products the judge labeled a first choice; a model naming several gives each of them that label. The full answer text for every row is in the record.
By buyer segment
MongoDB69%#1 of 10PostgreSQL5%#4 of 10MongoDB74%#1 of 13PostgreSQL2%#6 of 13MongoDB56%#1 of 9PostgreSQL0%#– of 9What the models said about MongoDB
Every negative label with a quote, up to three, then the highest-weighted positives, up to three. Five of six in this category shown.
“MongoDB's own docs warn that sharded clusters require careful planning and that poor shard-key choice can hurt scalability and performance.” GPT-5.4 mini · negative prompt · soft negative
“The most popular document database and production-ready, but with a long history of internet-exposed instances and NoSQL injection risk.” Muse Glimmer 30B · negative prompt · soft negative
“If you need a quick start with flexible JSON documents and strong consistency: MongoDB Community Edition self-hosted, or Atlas Free/Flex for a managed free tier.” Muse Glimmer 30B · budget prompt · first choice
“Often the default choice for B2B applications... For most mid-market B2B companies without extreme scale requirements, MongoDB ... are safe bets.” Claude Haiku 4.5 · direct prompt · first choice
“MongoDB Community Edition is often considered the most popular choice for budget-conscious companies due to its balance of features and ease of use.” Claude Haiku 4.5 · budget prompt · first choice
What the models said about PostgreSQL
Every negative label with a quote, up to three, then the highest-weighted positives, up to three. Three of three in this category shown.
“Before choosing any NoSQL database, ask yourself: "Why can't I use PostgreSQL?"” Gemini 3.5 Flash · negative prompt · first choice
“If your data is highly normalized and relational ... stick to Postgres.” Qwen 3.7 Flash · scale prompt · first choice
“modern trends suggest looking at PostgreSQL (specifically with JSONB) as the ultimate hybrid solution” Qwen 3.7 Flash · direct prompt · alternative
Comparisons are drawn for the top eight products in each category, each against each. The output is the models' output; nothing here is a recommendation by the index.