We need to produce article of 1500+ characters? Actually it's Chinese characters count, not words. Requires at least 1500 Chinese characters, cannot be less than 1050 characters. Must be 6-8 paragraphs, each 150-250 Chinese characters. Title already given, we output only the body, no title. Must be natural, conversational, no AI phrasing.
We need to write about "数据库结构迁移，平滑过渡的实战指南". Must be 6-8 paragraphs, each 150-250 characters. So total characters must be >=1500 and <=? Actually at least 1500, cannot be less than 1050. So we need at least 1500 Chinese characters in body. Each paragraph 150-250 characters. If we have 6 paragraphs, each average ~250 => 1500. If 7 paragraphs, average ~215 => ~1505. 8 paragraphs average ~188 => ~1504. So we need 6-8 paragraphs each 150-250 characters. Let's aim for 7 paragraphs of about 215 characters each => total ~1505 characters.
We need to count characters. Let's draft 7 paragraphs, each roughly 215 characters.
Paragraph 1: intro, echo title.
Paragraph 2: why migration matters, pain points.
Paragraph 3: planning and assessment.
Paragraph 4: design migration strategy (blue-green, canary).
Paragraph 5: data migration steps, tools, testing.
Paragraph 6: cutover and monitoring.
Paragraph 7: wrap-up, reflection.
We need to ensure each paragraph length 150-250 characters. Let's craft.
I'll draft paragraphs and then count characters roughly.
Paragraph1 (approx 210 chars):
"很多团队在系统升级或者业务重构时，都会遇到数据库结构迁移的难题。这次我们聊的，就是如何在不中断业务的情况下，平滑完成数据库结构的搬迁。标题里提到的‘平滑过渡’，其实就是把迁移这件事，当成一次细致的工程管理，而不是一次性的大改动。"
Count characters? Let's count roughly: I'll count manually.
"很多团队在系统升级或者业务重构时，都会遇到数据库结构迁移的难题。" = 30? Let's count precisely: 很多(2)团队(2)在(1)系统(2)升级(2)或者(2)业务(2)重构(2)时(1)，都(1)会(1)遇到(2)数据库(3)结构(2)迁移(2)的(1)难题(2)。 that's about 30? Hard to count precisely. But we need roughly 200 characters. Better to approximate but ensure each paragraph roughly 150-250 characters. It's okay if slightly off as long as total >=1500. Let's aim for 7 paragraphs each ~215 characters.
I'll write paragraphs with about 200-230 characters.
Let's write paragraph1 ~210 chars.
I'll write and then count roughly.
"很多团队在系统升级或者业务重构时，都会遇到数据库结构迁移的难题。这次我们聊的，就是如何在不中断业务的情况下，平滑完成数据库结构的搬迁。标题里提到的‘平滑过渡’，其实就是把迁移这件事，当成一次细致的工程管理，而不是一次性的大改动。"
Now count characters (including punctuation). Let's count roughly: I'll count each Chinese character and punctuation as one. Let's count manually:
很多团队在系统升级或者业务重构时，都会遇到数据库结构迁移的难题。 (Let's count: 很多(2)团队(2)在(1)系统(2)升级(2)或者(2)业务(2)重构(2)时(1)，都(1)会(1)遇到(2)数据库(3)结构(2)迁移(2)的(1)难题(2)。) That's about 2+2+1+2+2+2+1+1+1+2+3+2+2+1+2 = 30? Actually let's just approximate length: It's about 38 characters? Hmm.
Anyway, we need each paragraph 150-250 characters, not words. So we need to produce longer paragraphs.
Better to write longer paragraphs with about 200-250 characters each. Let's craft longer sentences.
Paragraph1: Let's write around 230 characters.
"很多团队在系统升级或者业务重构时，都会碰到数据库结构迁移的痛点。这次我们要聊的，正是如何在不影响线上服务的前提下，平滑完成数据库结构的搬迁。标题里提到的‘平滑过渡’，其实是把迁移当成一次系统化的工程，而不是一次性的大改动。"
Now count characters roughly: Let's count quickly.
很多团队在系统升级或者业务重构时，都会碰到数据库结构迁移的痛点。 (approx 30)
这次我们要聊的，正是如何在不影响线上服务的前提下，平滑完成数据库结构的搬迁。 (approx 38?)
标题里提到的‘平滑过渡’，其实是把迁移当成一次系统化的工程，而不是一次性的大改动。 (approx 38) Total maybe ~106. Need 150-250. So need longer.
Add more details: talk about why it's common, mention pain points, mention goal.
Let's rewrite paragraph1 with more content to reach ~200 characters.
"很多团队在系统升级、业务重构或者架构演进的过程中，都会遇到数据库结构迁移的尴尬。如果直接把表、字段、索引全扔掉重建，往往会导致服务不可用、数据不一致，甚至业务回滚。我们今天要讲的，就是如何在保持业务稳定的前提下，平滑完成数据库结构的迁移，让迁移变得可控、可追踪。"
Now count characters: Let's count roughly.
很多团队在系统升级、业务重构或者架构演进的过程中，都会遇到数据库结构迁移的尴尬。 (approx 38)
如果直接把表、字段、索引全扔掉重建，往往会导致服务不可用、数据不一致，甚至业务回滚。 (approx 40)
我们今天要讲的，就是如何在保持业务稳定的前提下，平滑完成数据库结构的迁移，让迁移变得可控、可追踪。 (approx 45) Total ~123. Still short.
Need 150-250 characters each. Let's expand more.
Add more sentences: mention typical scenarios, importance.
Paragraph1 final version maybe 210 characters.
"在实际项目中，数据库结构迁移几乎是每个技术团队不可避免的环节。无论是增加新表、拆分旧表，还是调整字段类型，都可能直接影响业务的连续性。如果缺乏计划，直接在生产库里改动，往往会导致服务中断、数据错误，甚至需要紧急回滚。我们今天的目标，就是帮助大家理清迁移的思路，找到一条既安全又高效的平滑过渡之路。"
Now count characters: Let's approximate. This seems around 200-230 characters. Let's count quickly:
在实际项目中，数据库结构迁移几乎是每个技术团队不可避免的环节。 (28)
无论是增加新表、拆分旧表，还是调整字段类型，都可能直接影响业务的连续性。 (38)
如果缺乏计划，直接在生产库里改动，往往会导致服务中断、数据错误，甚至需要紧急回滚。 (40)
我们今天的目标，就是帮助大家理清迁移的思路，找到一条既安全又高效的平滑过渡之路。 (38) Total ~144. Slightly under 150. Need a bit more.
Add a sentence: "本文将从需求分析到上线验证，一步步拆解迁移的关键点。" That's about 20 characters.
Add at end: "本文将从需求分析到上线验证，一步步拆解迁移的关键点。" That's about 20 characters.
Now total ~164, okay.
"在实际项目中，数据库结构迁移几乎是每个技术团队不可避免的环节。无论是增加新表、拆分旧表，还是调整字段类型，都可能直接影响业务的连续性。如果缺乏计划，直接在生产库里改动，往往会导致服务中断、数据错误，甚至需要紧急回滚。我们今天的目标，就是帮助大家理清迁移的思路，找到一条既安全又高效的平滑过渡之路。本文将从需求分析到上线验证，一步步拆解迁移的关键点。"
Now count roughly: seems around 200 characters. Good.
Paragraph2: talk about why need migration, pain points, benefits.
Paragraph2 draft ~210 characters.
"很多业务在成长过程中，会因为流量增长、功能扩展或是技术债务，导致原有的数据库结构不再适用。比如，原来的单表变得过于庞大，查询效率下降；又或者，业务需要
