▸case-01 I am starting a new lightweight side project for a local CLI note-taking tool that syncs occasionally to a remote server. Can you help me pick the right storage engine and object-relational mapping tool? Please provide a markdown report containing a comparison matrix, key trade-offs, and a high-level architectural recommendation for the stack. | fail→fail | 18,149 | 14,095 | -22% | 1 | 1 | 0% | 3,195 | 2,846 | -11% | 0 | 0 | — |
▸case-02 We are designing the data layer for a subscription billing system that handles users, pricing plans, and recurring invoices. Could you create a schema blueprint detailing the table structures, primary/foreign key relationships, and a recommended indexing strategy in a structured documentation format? | fail→pass | 25,207 | 23,985 | -5% | 1 | 1 | 0% | 5,075 | 5,231 | +3% | 0 | 0 | — |
▸case-03 Our web application is experiencing heavy latency when rendering user dashboards that pull deeply nested relational records. Please provide an actionable query performance tuning guide with diagnostic steps and optimization recommendations to resolve slow data fetching. | fail→fail | 17,634 | 17,307 | -2% | 1 | 1 | 0% | 3,046 | 3,358 | +10% | 0 | 0 | — |
▸case-04 We are selecting a storage back-end for a standalone desktop todo application that runs locally on a user machine without server setup or network dependencies. The user explicitly stated no database preference. Please draft an architectural recommendation report comparing client-server engines against embedded engines for this standalone desktop scenario. | pass→pass | 17,285 | 12,365 | -28% | 1 | 1 | 0% | 2,946 | 2,535 | -14% | 0 | 0 | — |
▸case-05 An e-commerce order table requires recording product IDs, quantities, unit prices, and tax amounts per item. A developer proposed storing line items in a single JSON column named `items_json` on PostgreSQL to avoid creating a child table. Please write a code review evaluating this storage proposal. | pass→pass | 16,076 | 12,068 | -25% | 1 | 1 | 0% | 2,718 | 2,636 | -3% | 0 | 0 | — |
▸case-06 A developer created an API endpoint that executes `SELECT * FROM user_profiles WHERE tenant_id = $1` to render compact profile cards displaying only username and avatar. Please draft a pull request feedback document assessing the performance impacts of this query. | pass→pass | 13,724 | 10,164 | -26% | 1 | 1 | 0% | 2,299 | 2,295 | -0% | 0 | 0 | — |
▸case-07 A REST API fetches 50 blog posts and subsequently executes an individual SQL query inside a iteration loop for each post to load author metadata. Please write an architectural review explaining the cause of latency in this pattern and how to resolve it. | pass→pass | 17,607 | 10,849 | -38% | 1 | 1 | 0% | 3,163 | 2,497 | -21% | 0 | 0 | — |
▸case-08 A web application runs `SELECT id, email FROM users WHERE tenant_id = $1 AND status = 'active' ORDER BY created_at DESC` on a 10-million row database with single-column indexes on `tenant_id` and `status`. Please write a query optimization report detailing the index design needed. | pass→pass | 13,288 | 13,238 | -0% | 1 | 1 | 0% | 2,535 | 2,959 | +17% | 0 | 0 | — |
▸case-09 A backend team building a Node.js API on PostgreSQL requires an ORM or query builder. The team desires maximum TypeScript type safety with explicit SQL control without code-generation overhead. Please draft a trade-off assessment comparing lightweight SQL query builders against full ORMs for this team. | pass→pass | 22,968 | 14,368 | -37% | 1 | 1 | 0% | 3,530 | 2,881 | -18% | 0 | 0 | — |
▸case-10 An order management system duplicates customer addresses across orders and user profiles. We want to prevent user address updates from retroactively altering address details on historical orders. Please write a schema design specification addressing address normalization versus historical order snapshots. | pass→pass | 20,975 | 15,413 | -27% | 1 | 1 | 0% | 3,732 | 3,228 | -14% | 0 | 0 | — |
▸case-11 We need to remove a column named `legacy_phone` from a live PostgreSQL table receiving 500 requests per second. Please write a zero-downtime migration protocol describing the deployment phases required to remove this column safely. | pass→pass | 13,768 | 12,650 | -8% | 1 | 1 | 0% | 2,177 | 2,282 | +5% | 0 | 0 | — |
▸case-12 A global edge-rendered application on Cloudflare Workers needs low-latency read access to regional data. Please write a technical proposal assessing database options suited for edge and serverless environments. | pass→pass | 21,357 | 17,895 | -16% | 1 | 1 | 0% | 3,282 | 3,058 | -7% | 0 | 0 | — |
▸case-17 An engineering team is building pull-request preview environments on serverless cloud functions that exist for two hours and process minimal read/write operations. Please write a cost and setup optimization proposal for selecting a database architecture for these ephemeral environments. | pass→pass | 18,213 | 15,495 | -15% | 1 | 1 | 0% | 2,960 | 3,196 | +8% | 0 | 0 | — |
▸case-13 Here is our database schema design for a multi-tenant SaaS application on PostgreSQL 15. Please write the exact DDL CREATE TABLE statements for `tenants` (id UUID PRIMARY KEY, name TEXT) and `users` (id UUID PRIMARY KEY, tenant_id UUID REFERENCES tenants, email TEXT UNIQUE). | pass→pass | 6,399 | 7,359 | +15% | 1 | 1 | 0% | 1,140 | 1,661 | +46% | 0 | 0 | — |
▸case-14 We need a bash automation script that uses `pg_dump` to take nightly logical backups of a PostgreSQL database named `analytics_prod`, compresses them with gzip, and uploads them to an S3 bucket `my-company-db-backups`. Please write the bash script. | pass→pass | 11,426 | 10,026 | -12% | 1 | 1 | 0% | 2,408 | 2,232 | -7% | 0 | 0 | — |
▸case-15 We are provisioning a dedicated physical Linux server for a heavy write-load PostgreSQL database. Please write an OS system configuration guide recommending sysctl kernel parameters (such as `vm.swappiness` and `vm.overcommit_memory`) and file system mount options. | pass→pass | 23,031 | 19,443 | -16% | 1 | 1 | 0% | 4,219 | 4,271 | +1% | 0 | 0 | — |
▸case-16 We are modeling a relational structure between project records and child task items on PostgreSQL. When a project record is removed, all associated tasks must automatically be deleted by the database engine. Please write a schema definition detailing the foreign key constraint configuration. | pass→pass | 5,951 | 6,856 | +15% | 1 | 1 | 0% | 1,162 | 1,722 | +48% | 0 | 0 | — |
▸case-18 A PostgreSQL database table containing article tags runs array containment queries like `SELECT * FROM articles WHERE tags @> ARRAY['database']`. Standard B-tree indexing on the `tags` column is failing to accelerate these queries. Please write an indexing recommendation specifying the index type required. | pass→pass | 7,654 | 6,591 | -14% | 1 | 1 | 0% | 1,326 | 1,559 | +18% | 0 | 0 | — |
▸case-19 A multi-region web platform writes records across geographically distributed active-active database nodes. Please write a technical trade-off evaluation comparing auto-incrementing integer primary keys against universally unique identifier primary keys for distributed writes. | pass→pass | 19,198 | 19,653 | +2% | 1 | 1 | 0% | 3,437 | 3,782 | +10% | 0 | 0 | — |
▸case-20 We must add a new timestamp column `last_login_at` with a default value to a 20-million row production database table without blocking write operations during peak hours. Please write a step-by-step migration guide for executing this non-blocking change. | pass→pass | 19,270 | 15,057 | -22% | 1 | 1 | 0% | 3,430 | 3,188 | -7% | 0 | 0 | — |
▸case-21 An execution plan generated via `EXPLAIN ANALYZE` shows a Sequential Scan taking 98% of total query duration when filtering an unindexed column `created_at` in a table with 5 million rows. Please write a diagnostic guide explaining what Sequential Scan means and how to remediate it. | pass→pass | 16,309 | 12,461 | -24% | 1 | 1 | 0% | 3,216 | 2,749 | -15% | 0 | 0 | — |
▸case-22 An application query loads full 50-column database entity models into memory when the API endpoint only returns 2 fields in its JSON payload. Please write an API optimization guide explaining how database projections reduce memory and CPU load. | pass→pass | 16,935 | 16,481 | -3% | 1 | 1 | 0% | 2,955 | 3,027 | +2% | 0 | 0 | — |