# Big Data Knowledge Test vs Database Keys and Constraints

The clearest difference is in-app purchases: Database Keys and Constraints at none against Big Data Knowledge Test's 2. Database Keys and Constraints also leads on device support (3 vs 1) and iOS requirement (15.1 vs 17.2). On price and ads there is nothing between them.

Both are free to download. Big Data Knowledge Test sells 2 in-app purchases, starting at $13.99 per month. Database Keys and Constraints asks for nothing beyond the download.

## The numbers

| Metric | Big Data Knowledge Test | Database Keys and Constraints |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 3 months | — |
| Size | 9 MB | 38 MB |
| Requires iOS | 17.2 | **15.1** |
| Devices | iPhone | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Cargo Teleport Inc](https://appshunter.io/developer/1761832181) | [Tsuyoshi Sezaki](https://appshunter.io/developer/1886356149) |

## What reviewers say

### Big Data Knowledge Test

[App page](https://appshunter.io/ios/app/big-data-knowledge-test/id6740737722)

**Features:** macOS Compatibility

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Premium monthly subscription | $13.99 | per month |
| Lifetime version | $24.99 | one-time |


### Database Keys and Constraints

[App page](https://appshunter.io/ios/app/database-keys-and-constraints/id6773622183)

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is Big Data Knowledge Test free?

Big Data Knowledge Test is free to download, with in-app purchases available.

### Is Database Keys and Constraints free?

Database Keys and Constraints is free to download, with no in-app purchases.

### Do Big Data Knowledge Test or Database Keys and Constraints have ads?

Neither Big Data Knowledge Test nor Database Keys and Constraints shows ads.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*