▸case-01 Our team is updating a high-traffic MySQL database table containing over 50 million rows to add new foreign key constraints and alter column types. Can you deliver an impact analysis, a zero-downtime rollout plan, executable migration scripts, data integrity verification queries, manual and automated rollback commands, batch processing guidelines to prevent lock contention, and setup details for tracking migration progress? | fail→pass | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-09 We need to alter a primary key and rebuild clustered indexes on a 500 GB partitioned transactions table in SQL Server Enterprise Edition. What is the zero-downtime rollout and script strategy? | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-03 We are migrating our MongoDB cluster from an unsharded collection to a sharded cluster using hash-based shard keys. We want guidance on chunk migrations, balancer settings, and mongos configuration. | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-13 In SQL Server, we are splitting a wide orders table into orders and order_deliveries. High read/write activity continues throughout the deployment. Deliver the implementation strategy, scripts, and validation suite. | fail→pass | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-04 Our reporting query joining 5 tables in PostgreSQL is taking 15 seconds to run on standard SELECT queries. Can you rewrite the SQL query using CTEs and window functions to optimize execution time without making schema changes? | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-02 We are migrating a legacy user table in SQL Server to a new normalized schema while keeping our services online. I need a comprehensive deliverable that includes an analysis report of the schema updates, a zero-downtime deployment approach, all required SQL scripts, verification suites to confirm data correctness, safe rollback scripts, batching strategies to reduce lock escalation, and monitoring integration guidance. | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-17 We need to change the primary key of a MySQL InnoDB table from auto-increment BIGINT to a composite primary key (tenant_id, id). What is the zero-downtime implementation plan, SQL scripts, and rollback strategy? | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-07 We are renaming the column usr_phone to phone_number in an active MySQL 8.0 production database where microservices are constantly reading and writing. We are thinking of dropping the old column and adding the new column in one transaction. Provide the complete migration rollout plan and scripts. | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-10 We are deprecating a legacy_bio text column from our PostgreSQL users table. Provide the zero-downtime strategy and SQL scripts to safely remove this column without breaking running app instances. | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-19 A PostgreSQL table session_data has heavy bloat (70% dead tuples) and 50 GB of wasted disk space. VACUUM FULL locks the table for hours. How do we reclaim space with zero downtime? | fail→pass | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-12 We need to convert a monolith non-partitioned audit_logs table (200 million rows) in PostgreSQL into range-partitioned tables by month while keeping log ingestion active. Provide the migration analysis, strategy, and executable scripts. | pass→pass | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-06 We need to add a NOT NULL column tenant_id to a 100-million row events table in PostgreSQL 14 without holding an exclusive table lock that causes downtime. We're tempted to just run ALTER TABLE events ADD COLUMN tenant_id UUID NOT NULL DEFAULT '00000000-0000-0000-0000-000000000000' directly in a single DDL statement. Show us how to do this safely with full documentation. | fail→pass | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-05 We are building a Typescript Node.js app using TypeORM. Can you generate the TypeScript class definitions and decorated entity interfaces for our existing user, post, and comment models? | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-08 We need to add a composite index on (customer_id, created_at DESC) to a PostgreSQL orders table with 80 GB of data. A junior dev suggested running CREATE INDEX idx_cust_created ON orders (customer_id, created_at DESC); during low traffic. How should this be executed safely? | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-18 We need to change a column account_number from VARCHAR(20) to NVARCHAR(50) on a SQL Server table with 25 million rows. Direct ALTER TABLE takes the table offline. How do we migrate safely? | fail→pass | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-15 We need to add a new value 'PENDING_APPROVAL' to an existing PostgreSQL custom ENUM type order_status in production. What is the safest SQL migration script and rollback plan? | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-20 In MySQL 8.0, we extract user_settings->>'$.theme' frequently in SELECT queries. We want to promote theme to a generated regular column with an index. Deliver the migration strategy and scripts. | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-14 We need to enforce a foreign key constraint between order_items.product_id and products.id on a MySQL 8.0 database with 15 million existing rows in order_items. Adding FK constraints directly locks the child table. How do we execute this with zero downtime? | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-11 We are modifying an ENUM column definition to add new values on a MySQL 5.7 InnoDB table with 30 million rows. Direct ALTER TABLE locks the table for over 20 minutes. Outline the migration strategy and scripts to perform this change online. | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-16 We are migrating data from a legacy JSON column metadata->>'user_ip' to a dedicated ip_address INET column across 40 million rows in PostgreSQL. Running a single UPDATE users SET ip_address = (metadata->>'user_ip')::inet freezes the database. Provide the migration script. | fail→pass | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-21 We want to enable System-Versioned Temporal Tables on an existing core SQL Server table contracts containing 10 million rows without taking down the contract management system. Outline the rollout plan and scripts. | fail→pass | — | — | — | — | — | — | — | — | — | — | — | — |
▸case-22 We need to add a foreign key constraint from payments.user_id to users.id in PostgreSQL on a live system with millions of rows. How do we add and validate the constraint without holding an AccessExclusiveLock during validation? | fail→fail | — | — | — | — | — | — | — | — | — | — | — | — |