# Querycairn: Explain Plans — Read PostgreSQL Plan JSON

> Read PostgreSQL Plan JSON (iPhone/iPad app by Robert Corbin.)

- Source: https://appshunter.io/ios/app/querycairn-explain-plans/id6792557968 (this page in markdown: same URL + `.md`)
- Developer: [Robert Corbin](https://appshunter.io/developer/1890247992)
- Category: Developer Tools, Productivity
- Price: $2.99
- Age rating: 4+
- Requires: iOS 17.0 · 2 MB
- Languages: English
- Released: 2026-07-29
- Data updated: 2026-09-09
- User reviews in markdown: https://appshunter.io/ios/app/querycairn-explain-plans/id6792557968/reviews.md

## What is Querycairn?

Querycairn is a private query-plan interpretation bench for developers, database administrators, consultants, and technical teams who need a focused second screen without pasting schema or plans into a website.

Surface the nodes where row-estimate error and loop amplification make a seemingly small plan expensive.

KEY FEATURES
- PostgreSQL EXPLAIN JSON import
- Recursive plan-node inventory
- Estimated-versus-actual row view
- Loop and predicate risk scoring
- Node owner and hypothesis notes
- Statistics and index checklist
- Plan findings export
- Database credentials never requested
- Native structured-file or CSV import
- Local PDF, workspace JSON, and domain-artifact export
- No account, ads, analytics, tracking, IAP, or subscription

Querycairn interprets recorded PostgreSQL plan fields and entered context; it does not connect to a database, execute SQL, recommend an index automatically, or prove a change is safe. EXPLAIN ANALYZE executes the statement. Use controlled data, representative parameters, and expert review.


## Version history (last 2 releases)

### 1.1 — 2026-08-31

Removes about 35 MB of artwork the app never displayed. Plan parsing and the cost breakdown work as before.

### 1.0 — 2026-07-29

No release notes.

## More apps by Robert Corbin

- [Daily Word Journey](https://appshunter.io/ios/app/daily-word-journey/id6761548266)
- [Hush Secret Text](https://appshunter.io/ios/app/hush-secret-text/id6761658175)
- [Renew Guard](https://appshunter.io/ios/app/renew-guard/id6761755447)
- [Receipt to PDF](https://appshunter.io/ios/app/receipt-to-pdf/id6761782025)
- [Route Your Pay](https://appshunter.io/ios/app/route-your-pay/id6761783719)
- [Tip Arbiter](https://appshunter.io/ios/app/tip-arbiter/id6761786879)

All apps by Robert Corbin: https://appshunter.io/developer/1890247992

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-09-09.*