By Bruce Jenkins, President, Ora Research
Onshape Engineering团队成员Ilya Baran发表的一篇启发性博客文章揭示了一些新的云本地CAD系统的基础知识：“我们谨慎区分几种类型的数据：User Interface (UI) state- 例如，选择，相机视图，当前选项卡；这Part Studio definition- 例如，功能列表，零件名称和颜色，导入数据；[和]再生结果– the “b-rep” (bodies, faces, edges, etc.), triangles for display, regen errors.”
How do these data types differ? “The UI state generally doesn’t persist (except for things like named views),” Baran writes. “The regeneration results are cached, but they can always be rebuilt from the definition. The Part Studio definition is what we store in the database and that is where collaborative editing happens.”
Then Baran explains something that begins to suggest why we believe Onshape is not only a breakthrough in CAD, but also poised to disrupt the established paradigm for PLM platforms. “For a given Part Studio, at each point in time, the definition is stored as an eternal, immutable object that we internally call a microversion,” he writes. “Whenever the user changes the Part Studio definition (e.g., edits an extrude length, renames a part, or drags a sketch), we do not change an existing microversion, but create a new one to represent this new definition. The new microversion stores a reference to the previous (parent) microversion and the actual definition change. In this way, we store the entire evolution of the Document: this is accessible to the user as the Document history, allowing the user to reliably view and restore any prior state of an Onshape Document.”
Onshape Follow Mode. Source: Onshape
Next Baran reveals how Onshape is fundamentally different from older-generation engineering software. “Basing Onshape on immutable microversions also makes for a great foundation for other collaboration tools: those we already have, such as the Follow Mode or the Compare tool, as well as those we are developing for the future,” he says. “It also has benefits beyond just collaboration abilities: because old microversions are never modified, data integrity is better preserved, and having a history of changes allows us to debug exactly how a Document came to be when a user has a problem or when we detect a problem through our logs.”
新的云本地数据库体系结构改变了一切
What makes all this possible and practical? Much of the answer lies in Onshape’s being built on MongoDB, one of the new “NoSQL” databases widely used in cloud-native applications, instead of any of the relational database management systems (RDBMS) used in most engineering applications until now. “Relational databases were not designed to cope with the scale and agility challenges that face modern applications,” MongoDB says, “nor were they built to take advantage of the commodity storage and processing power available today.” MongoDB functions as back-end software for Craigslist, eBay, Foursquare, LinkedIn and many other of today’s massively deployed cloud-based services.
Besides being fast, scalable and designed to exploit cloud computing resources, NoSQL databases have a capability called “schema-on-read.” This allows data to be captured, stored and subsequently acted on with almost limitless freedom, without the application developer having to create a schema for the data in advance. Having to create such a schema as the first step in creating a database, a requirement of traditional RDBMS technology, is known as“schema-on -write.”
NOSQL数据库提供商Marklogic的Joe Pasqua解释了架构读取的好处：“数十年来，数据库世界一直针对固定架构的方法。首先，您定义模式，然后编写数据，然后读取数据，然后在预先定义的模式中返回。这种方法在我们的思想中深深地根深蒂固，许多人会问：“您还将如何做？”答案是读取的架构。读取模式遵循不同的顺序 - 只需将数据按原样加载，然后在您读取数据时将自己的镜头应用于数据。”
What’s the advantage? “More and more these days, data is a shared asset among groups of people with differing roles and differing interests – who want to get different insights from that data,” Pasqua explains. “With schema-on-write, you have to think about all of these constituencies in advance and define a schema that has something for everyone, but isn’t a perfect fit for anyone. When you are talking about huge volumes of data, it just isn’t practical. With schema-on-read you can present data in a schema that is adapted best to the queries being issued. You’re not stuck with a one-size-fits-all schema.”
But that’s not all. “One of the places where projects often go off the rails is when multiple datasets are being consolidated,” Pasqua continues. “With schema-on-write, you have to do an extensive data modeling job and develop an über-schema that covers all of the datasets that you care about. Then you have to think about whether your schema will handle the new datasets that you’ll inevitably want to add later. If you’re lucky enough to get through that process, Murphy will strike again and you’ll be asked to add, change or drop a column (or two or three). With schema-on-read, this upfront modeling exercise disappears.”
“In time, Onshape will be the system of record for all types of data & meta-data”
那些Onshape数据库体系结构的基本功能以及其进口，操作和归档其他工程应用程序的能力 - 开始暗示公司长期野心和愿景的真正范围和规模。确实，它并没有秘密。大约在去年Onshape公开亮相时，一位用户在其在线讨论论坛上发布：“最终打算开发PLM，还是他们会走上合作伙伴的路线来提供？我之所以问，是因为Onshape是一个具有正确平台的数据库系统，可以看似处理此功能。”
In reply, Steve Hess from Onshape’s UX/PD team posted:“As you know Onshape was built with data management in mind. The data management features of Onshape are at the core of the product and will become more exposed as Onshape matures.In time, Onshape will be the system of record for all types of data & meta-data…您的其他企业系统将可见且可访问存储在Onshape中的数据。”（我们的重点。）
已经使多个用户可以同时进行相同设计的方式来消除了许多问题，这些问题已建立了PDM和PLM提供商已花费了数年的时间“解决”，同时又持续了许多问题，因为它们的系统架构构建了它们的系统架构。上。正如Onshape创始人兼董事长Jon Hirschtick告诉我们的那样：“对于初学者来说，我们消除了传统PDM的所有功能的50-60％ - 他们根本没有在我们的世界中没有作用（复制文件，管理目录结构等）。”
Far from being a throwaway line, we think Hirschtick’s phrase “for starters” is in dead earnest. To date, Onshape’s best-understood benefits are how it removes many of the headaches and costs of locally installed software, and of CAD collaboration and data management. But we believe its larger goal is to evolve a next-generation product development platform that “in time,” as Hess declared, “will be the system of record for all types of data and meta-data.”
Onshape做到这一点的能力基于读取模式的两个关键好处。首先，它“为如何消耗数据提供了极大的灵活性，” Tom Deutsch，带有IBM的解决方案CTO解释，其次，“您的原始/原子数据可以存储在未来的参考和消费几年中。”这些位置的浮现将其对CAD协作和数据管理的根本简化扩展到越来越多的PLM领域，在该领域中，用户拥有足够的复杂性和费用，并准备好进行新事物。
ORA研究
oraresearch.com
提交以下：3 d CAD世界
