# Send database-migrations to your agent Hand the extracted package to your coding agent with a concrete install brief instead of figuring it out manually. ## Fast path - Download the package from Yavira. - Extract it into a folder your agent can access. - Paste one of the prompts below and point your agent at the extracted folder. ## Suggested prompts ### New install ```text I downloaded a skill package from Yavira. Read SKILL.md from the extracted folder and install it by following the included instructions. Then review README.md for any prerequisites, environment setup, or post-install checks. Tell me what you changed and call out any manual steps you could not complete. ``` ### Upgrade existing ```text I downloaded an updated skill package from Yavira. Read SKILL.md from the extracted folder, compare it with my current installation, and upgrade it while preserving any custom configuration unless the package docs explicitly say otherwise. Then review README.md for any prerequisites, environment setup, or post-install checks. Summarize what changed and any follow-up checks I should run. ``` ## Machine-readable fields ```json { "schemaVersion": "1.0", "item": { "slug": "database-migrations", "name": "database-migrations", "source": "tencent", "type": "skill", "category": "开发工具", "sourceUrl": "https://clawhub.ai/wpank/database-migrations", "canonicalUrl": "https://clawhub.ai/wpank/database-migrations", "targetPlatform": "OpenClaw" }, "install": { "downloadUrl": "/downloads/database-migrations", "sourceDownloadUrl": "https://wry-manatee-359.convex.site/api/v1/download?slug=database-migrations", "sourcePlatform": "tencent", "targetPlatform": "OpenClaw", "packageFormat": "ZIP package", "primaryDoc": "SKILL.md", "includedAssets": [ "README.md", "SKILL.md" ], "downloadMode": "redirect", "sourceHealth": { "source": "tencent", "slug": "database-migrations", "status": "healthy", "reason": "direct_download_ok", "recommendedAction": "download", "checkedAt": "2026-05-11T22:16:02.052Z", "expiresAt": "2026-05-18T22:16:02.052Z", "httpStatus": 200, "finalUrl": "https://wry-manatee-359.convex.site/api/v1/download?slug=database-migrations", "contentType": "application/zip", "probeMethod": "head", "details": { "probeUrl": "https://wry-manatee-359.convex.site/api/v1/download?slug=database-migrations", "contentDisposition": "attachment; filename=\"database-migrations-1.0.0.zip\"", "redirectLocation": null, "bodySnippet": null, "slug": "database-migrations" }, "scope": "item", "summary": "Item download looks usable.", "detail": "Yavira can redirect you to the upstream package for this item.", "primaryActionLabel": "Download for OpenClaw", "primaryActionHref": "/downloads/database-migrations" }, "validation": { "installChecklist": [ "Use the Yavira download entry.", "Review SKILL.md after the package is downloaded.", "Confirm the extracted package contains the expected setup assets." ], "postInstallChecks": [ "Confirm the extracted package includes the expected docs or setup files.", "Validate the skill or prompts are available in your target agent workspace.", "Capture any manual follow-up steps the agent could not complete." ] } }, "links": { "detailUrl": "https://openagent3.xyz/skills/database-migrations", "downloadUrl": "https://openagent3.xyz/downloads/database-migrations", "agentUrl": "https://openagent3.xyz/skills/database-migrations/agent", "manifestUrl": "https://openagent3.xyz/skills/database-migrations/agent.json", "briefUrl": "https://openagent3.xyz/skills/database-migrations/agent.md" } } ``` ## Documentation ### Schema Evolution Strategies StrategyRiskDowntimeBest ForAdditive-OnlyVery LowNoneAPIs with backward-compatibility guaranteesExpand-ContractLowNoneRenaming, restructuring, type changesParallel ChangeLowNoneHigh-risk changes on critical tablesLazy MigrationMediumNoneLarge tables where bulk migration is too slowBig BangHighYesDev/staging or small datasets only Default to Additive-Only. Escalate to Expand-Contract only when you must modify or remove existing structures. ### Zero-Downtime Patterns Every production migration must avoid locking tables or breaking running application code. OperationPatternKey ConstraintAdd columnNullable firstNever add NOT NULL without default on large tablesRename columnExpand-contractAdd new → dual-write → backfill → switch reads → drop oldDrop columnDeprecate firstStop reading → stop writing → deploy → dropChange typeParallel columnAdd new type → dual-write + cast → switch → drop oldAdd indexConcurrentCREATE INDEX CONCURRENTLY — don't wrap in transactionSplit tableExtract + FKCreate new → backfill → add FK → update queries → drop old columnsChange constraintTwo-phaseAdd NOT VALID → VALIDATE CONSTRAINT separatelyAdd enum valueAppend onlyNever remove or rename existing values ### Migration Tools ToolEcosystemStyleKey StrengthPrisma MigrateTypeScript/NodeDeclarative (schema diff)ORM integration, shadow DBKnexJavaScript/NodeImperative (up/down)Lightweight, flexibleDrizzle KitTypeScript/NodeDeclarative (schema diff)Type-safe, SQL-likeAlembicPythonImperative (upgrade/downgrade)Granular control, autogenerateDjango MigrationsPython/DjangoDeclarative (model diff)Auto-detectionFlywayJVM / CLISQL file versioningSimple, wide DB supportgolang-migrateGo / CLISQL (up/down files)Minimal, embeddableAtlasGo / CLIDeclarative (HCL/SQL diff)Schema-as-code, linting, CI Match the tool to your ORM and deployment pipeline. Prefer declarative for simple schemas, imperative for fine-grained data manipulation. ### Rollback Strategies ApproachWhen to UseReversible (up + down)Schema-only changes, early-stage productsForward-only (corrective migration)Data-destructive changes, production at scaleHybridReversible for schema, forward-only for data ### Data Preservation Soft-delete columns — rename with _deprecated suffix instead of dropping Snapshot tables — CREATE TABLE _backup__ AS SELECT * FROM
Point-in-time recovery — ensure WAL archiving covers migration windows Logical backups — pg_dump of affected tables before migration ### Blue-Green Database 1. Replicate primary → secondary (green) 2. Apply migration to green 3. Run validation suite against green 4. Switch traffic to green 5. Keep blue as rollback target (N hours) 6. Decommission blue after confidence window ### Backfill Strategies StrategyBest ForInline backfillSmall tables (< 100K rows)Batched backfillMedium tables (100K–10M rows)Background jobLarge tables (10M+ rows)Lazy backfillWhen immediate consistency not required ### Batch Processing DO $$ DECLARE batch_size INT := 1000; rows_updated INT; BEGIN LOOP UPDATE my_table SET new_col = compute_value(old_col) WHERE id IN ( SELECT id FROM my_table WHERE new_col IS NULL LIMIT batch_size FOR UPDATE SKIP LOCKED ); GET DIAGNOSTICS rows_updated = ROW_COUNT; EXIT WHEN rows_updated = 0; PERFORM pg_sleep(0.1); -- throttle to reduce lock pressure COMMIT; END LOOP; END $$; ### Dual-Write Period For expand-contract and parallel change: Dual-write — application writes to both old and new columns/tables Backfill — fill new structure with historical data Verify — assert consistency (row counts, checksums) Cut over — switch reads to new, stop writing to old Cleanup — drop old structure after cool-down period ### Test Against Production-Like Data Never test against empty or synthetic data only Use anonymized production snapshots Match data volume — a migration working on 1K rows may lock on 10M Reproduce edge cases: NULLs, empty strings, max-length, unicode ### Migration CI Pipeline - name: Test migrations steps: - run: docker compose up -d db - run: npm run migrate:up # apply all - run: npm run migrate:down # rollback all - run: npm run migrate:up # re-apply (idempotency) - run: npm run test:integration # validate app - run: npm run migrate:status # no pending Every migration PR must pass: up → down → up → tests. ### Pre-Migration Tested against production-like data volume Rollback written and tested Backup of affected tables created App code compatible with both old and new schema Execution time benchmarked on staging Lock impact analyzed Replication lag monitoring in place ### During Migration Monitor lock waits and active queries Monitor replication lag Watch for error rate spikes Keep rollback command ready ### Post-Migration Schema matches expected state Integration tests pass against migrated DB Data integrity validated (row counts, checksums) ORM schema / type definitions updated Deprecated structures cleaned up after cool-down Migration documented in team runbook ### NEVER Do NEVER run untested migrations directly in production NEVER drop a column without first removing all application references and deploying NEVER add NOT NULL to a large table without a default value in a single statement NEVER mix schema DDL and data mutations in the same migration file NEVER skip the dual-write phase when renaming columns in a live system NEVER assume migrations are instantaneous — always benchmark on production-scale data NEVER disable foreign key checks to "speed up" migrations in production NEVER deploy application code that depends on a schema change before the migration has completed ## Trust - Source: tencent - Verification: Indexed source record - Publisher: wpank - Version: 1.0.0 ## Source health - Status: healthy - Item download looks usable. - Yavira can redirect you to the upstream package for this item. - Health scope: item - Reason: direct_download_ok - Checked at: 2026-05-11T22:16:02.052Z - Expires at: 2026-05-18T22:16:02.052Z - Recommended action: Download for OpenClaw ## Links - [Detail page](https://openagent3.xyz/skills/database-migrations) - [Send to Agent page](https://openagent3.xyz/skills/database-migrations/agent) - [JSON manifest](https://openagent3.xyz/skills/database-migrations/agent.json) - [Markdown brief](https://openagent3.xyz/skills/database-migrations/agent.md) - [Download page](https://openagent3.xyz/downloads/database-migrations)