雲端運算環境的興起，軟體即服務(Software as a Service, SaaS)的營運模式也開始受到軟體開發商的注意，其中一項關鍵技術是支援多租戶的軟體開發。在設計多租戶應用程式時有許多需要考量的因素，包含每個租戶各自的客製化設定、資料安全性等等。本論文著重於資料層級的客製化部份，如何讓各個租戶之間可以共用資料庫，但又能提供租戶適度地更改其資料表綱要(schema)以達到客製化的需求。 為了解決資料層級客製化所面臨的問題，一種常見的作法是可延伸性表格(Extension Table Layout)。但是，在關聯式資料庫中實作可延伸性表格，軟體開發人員為了配合可延伸性表格的資料存放方式，所使用的SQL語句會變得相當複雜且易錯。因此，本研究實作一個系統工具協助軟體開發人員將SQL語句，從一租戶一資料表寫法自動轉換成以可延伸性表格邏輯表達的SQL語句，透過執行轉換後的語句來對儲存在可延伸性表格的資料進行增刪修改。 軟體開發人員在本系統工具的協助下，加入租戶識別碼(TenanId)的開發概念後，即可實際建立一個多租戶應用程式。為了評估本系統工具的效用，我們以其建置了一個多校(租戶)選課系統，並進行多項效能實驗以探討影響本系統工具效能的因素。初步的結果顯示，本系統工具可以協助軟體開發人員，以較低的代價滿足資料層級客製化應用的需求。 / Software as a service (SaaS) is an emerging service model of cloud computing. One of the key technology in SaaS is supporting multi-tenant applications. There are many considerations in the design of multi-tenant applications, including customized configuration of tenants and data security. In this thesis, we focus on data-level customized configuration, and propose an approach for not only sharing database between tenants but also supporting tenants to modify their table schemas within limits. Extension Table Layout is one solution for solving the problems in data-level customized configuration for multi-tenant applications. However, SQL statemenst based on the Extension Table Layout are rather complicated and error-prone. Thus, we develop a tool to help software developers that will automatically rewrite the SQL statements from the common Private Table Layout into those from the Extension Table Layout at runtime. In other words, our tool enable software developers to write SQL statements in a multi-tenant application like in a single tenant application. Indeed, software developers could develop a multi-tenant application easily by using our tool and the multi-tenant enabler - TenantId. In order to assess the feasibility of our tool, we develop an online multi-tenant course election application. Besides, we disscus the effectiveness of the factors that affecting our tool and work on a number of experiments and performance tests. The preliminary results show that our SQL rewriting tool can help software developers at a lower cost to meet the needs of data-level customized applications to a degree.

近年來雲端運算蓬勃發展，為資訊系統的建置與服務帶來巨大的改變，其中一個重要趨勢為軟體即服務，並透過多租戶共享資源達到降低成本的優勢。因此如何讓服務可以共享資源，又能兼顧各租戶的客製化需求，這將會是軟體即服務關鍵成功因素。 為了讓租戶客製化自己的綱要，在多租戶的相關研究中，發展出各種綱要映射技術，各適用不同的狀況，但在開發應用程式時候往往無法預估租戶適合使用何種綱要映射技術。本研究提出可以讓多租戶軟體框架具有綱要映射技術的可調性，應用程式開發時候毋需考慮使用何種綱要映射技術，等租用時候再依據應用程式及租戶的特性決定。本研究將以小量租戶效能最佳的Private Table Layout與適合用於大量租戶的Universal Table Layout為例，提出的可調性多租戶實體模式來建構具有可調性的多租戶軟體框架。此外本研究提出的軟體框架經過技術的封裝，開發者不需要了解多租戶的相關技術，就能完成多租戶應用程式的開發。 / Software as a service (SaaS) is an emerging service model of cloud computing. It’s central defining characteristic is the ability for clients to use a software application on a pay-as-you-go subscription basis. However, to be economically sustainable, a SaaS application must leverage resource sharing to a large degree by accommodating different clients of the application while making it appear to each that they have the application all to themselves. In other words, a SaaS application must be a multi-tenant application. An important multi-tenant research topic is the various kinds of schema mapping technology have been developed in order for our tenants to customize their schema. However, it is hard to determine tenants’ need for particular schema mapping technology in different circumstances. This thesis proposes an adaptable schema mapping technology for a multi-tenant application (MTA) framework. The application and tenants’ characteristics do not need to be considered while applications developers are developing their schema mapping technology. This approach will take examples from the Private Table Layout mapping and the Universal Table Layout mapping to illustrate the features of this adaptable multi-tenant software framework. Furthermore, this thesis argues that, with the approach packaged as a software framework, developers are able to complete the development of a multi-tenant application without full understanding of the underlying technologies.

隨著雲端運算的服務租用理念越來越受到重視，SaaS 服務供應商在提供服務的時候無不希望可以以最少的成本服務最多的客戶，於是吸引了許多的研究者投入精力以及時間，希望可以設計出讓租戶們共享資源又能夠有客製化空間的解決方案。服務供應商為了順利推廣多租戶軟體開發，其中一項關鍵技術是支援 SQL 語句自動轉換機制，目的是協助 SQL 語句轉換成以多租戶資料架構邏輯表達的 SQL 語句，讓租戶應用程式的軟體開發人員能夠專注在自身的應用程式開發。 開發 SQL 語句自動轉換機制，必須先選定資料庫的資料架構，本論文採用 Universal Table Layout 這個 SaaS 多租戶資料共享常見的資料架構。 我們參考知名 SaaS 廠商 Force.com 的 Universal Table Layout 資料架構，並提出一些修正。其次，我們應用關聯式代數抽象化來設計 SQL 語句的轉換規則，這些理論結果不僅在表達轉換機制上更具有一般性，並且讓轉換規則的理解也變得更加容易。我們以這些理論推導為基礎實現一個實驗的工具，最後透過幾個實驗，觀察及探討實驗數據所呈現的意義。

近年來，雲端運算中的軟體即服務(Software as Service，SaaS)穩健與快速地成長。SaaS服務提供者在建置服務的過程中，無不希望盡可能地讓租戶共享資源，避免租戶擁有特殊資源，需要獨立維護，以降低維護營運成本。另一方面，也要能讓租戶們擁有一定程度的客製化能力，以製做出屬於租戶私有之服務邏輯。因此如何讓租戶在共有一切資源的前提下，又能提供客製化能力，將是SaaS服務提供者的一大課題。本研究所提出的中介軟體框架將在共用硬體及資料庫與單一應用程式的共用架構下，採用Force.com Universal Table資料架構，並提供三大特色功能，Tenant Aware、Data Access以及Tenant Customizability，來解決隔離性、存取Force.com Universal Table資料架構以及提供租戶客製化能力三大議題。透過此中介軟體框架應可幫助SaaS提供者，建置出一個資源共享、租戶具有客製能力與維護性高的多租戶雲端軟體服務。 / In recent years, Software as a service (SaaS), the service model of cloud computing, has been growing healthy and rapidly. When SaaS providers build service, they want tenants to share same resources, and not to have its own special resource which will cause providers to maintain it separately. SaaS providers want tenants sharing the same resources to reduce maintenance cost. But the current trend is to provide the customizability to tenants for customizing its own service. How to share resources under the premise of providing customizability to tenants will be the main challenge to SaaS providers. In this thesis, we propose a middleware framework based on shared hardware、database with a single application instance. Our framework will use the Force.com Universal Table schema as the foundation. The key features of our framework are Tenant Aware、Data Access and Tenant Customizability. These features will address the issues of isolating tenants, accessing the Force.com Universal Table schema and providing customizability to tenants. This middleware framework will help SaaS providers to build a resource-sharing, customizable multi-tenant SaaS with lower maintenance cost.

傳統展演中，觀眾和表演者被視為是兩個獨立的個體，表演者與表演者間及表演者與觀眾間互動不多，若使用穿戴式裝置結合科技與藝術的「虛實互動數位展演」，能協助營造現場的互動氣氛，是既新穎又富有創意的表演模式，還能結合故事劇情與觀眾互動，此種互動的情境氛圍，會比一般的資訊傳遞更容易讓觀眾有所感受。 而目前許多表演活動的展演特效系統，都是由特效控制技術人員根據展演人員的動作與節目進程來呈現。如果由展演人員自行操作、建置與管理的話，便需要瞭解特效控制的相關技術，此外也需要和技術人員互相溝通與合作。而彼此觀念、資訊與背景的不同，難免容易造成控制上的失誤、延遲或是溝通不良導致表演效果不佳以致於觀眾不好的視聽感受。基於上述問題，本研究將設計一個基於多租戶概念的雲端互動展演系統整合平台，展演人員只需透過網路連結至展演系統網站，配合連網感應器的穿戴式裝置，不需自行建置、管理系統平台，登入後可依個人需求使用直覺圖形化邏輯編輯器，使用滑鼠拖拉，控制需求，不需繁複的技術教學訓練，便根據穿戴式裝置回傳的感測訊號做出響應式的展演效果變化，達到展演人員可簡單好上手地自行操作展演特效系統，減少與特效控制技術人員合作上的失誤。 / In traditional performance art, viewers and performers are regarded as two independent individuals. There is less interaction between performers and performers, performers and audiences. If wearable devices are used in the "cyber-physical interactive digital performance art", it can help create an interactive atmosphere in the scene. It is a creative, innovative mode of performance, and it also creates a combination between scenario and the interaction of the audiences. The interactive atmosphere is easier for the audience to be affected than ordinary information transmission. Currently, many special effects are presented by the technical staff. They are based on the performers and progression of show. If the special effects are managed by the performer-selves, they need to understand the relative technologies. In addition, they have to cooperate and communicate with technical staff. However, the difference of concept and background between each other, it's hard to avoid the mistake, delay, or misunderstanding of control. It may cause that the poor performance bring audience about the bad auditory and visual feeling. According to above issues, this study will design and implement a multi-tenant cloud platform for cyber-physical interactive performance art. The performers just connect to the performance art system website via the Internet, with the wearable device, and they do not need to set up and manage system platform by themselves. They log in the website, with the GUI editor, and use mouse to control demand. Without complex technical training, the variety of special effects are presented which based on the wearable device’s signal. We suppose that the platform makes the performers operate special effects system by themselves simply and easily. It also reduces the misunderstanding with the technical staff.