ceenet databases

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Databases on the Internet David Billard David.Billard@cui.unige.ch 4th CEENet Workshop on Network Technology Bratislava, Slovakia, August 21-31, 1998

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Outline Classical databases Why should it be different in the Internet? Organizing the data with the Araneus methodology Building dynamically a web site with the Target Form Expression Dealing with security Using transactions and workflows

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Classical Databases Entity-Relationship (ER) model Relational model Oracle DBMS

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Classical Database Environment A classical Database Management System (DBMS) is composed of: interpretation of requests ACID properties Atomicity (all or nothing) Consistency Isolation Durability

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What is different with the Internet? Hypertext data: relational tables are 2-dimensions: tuples (lines) attributes (columns) relational tables do not content navigational data ; hypertext pages implements the third dimension of access path to the data Entity-relation scheme must evolve; Relations must be queried with the third dimension in mind. Consequences:

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What is different with the Internet? Internet technology: no guaranty of service (the RSVP is not fully implemented in IP, expected to be in IPng); unsecure channel of communication; lack of the notion of user (only machines); high probability of system crash; very sensible to scale problems. we must implement recovery protocols; we must implement security features. Consequences:

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What is different with the Internet? User behaviour: the user's actions are unknown and unpredictable we cannot use tightly coupled integration of the servers; we must define a minimal set of mandatory functionalities for interoperation. Strong heterogeneity: a DBMS cannot know every other DBMS technology to interact Consequences:

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Organizing the data for their use via the Web Web sites containing valuable pieces of information Web sites containing high volume of data, retrieved from databases Data organized in hypertextual form (access paths are part of the model) What we have:

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Organizing the data for their use via the Web What we need: a methodology for the: Database design process Hypertext design process a tool for: generating web sites from databases maintaining these web sites

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The ARANEUS Project (Univ. Roma 3)

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The ARANEUS Project 1:N 1:1 University ER scheme 1:N 1:1 1:1 1:N name type day hour roomNum phone name photo e-mail

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The ARANEUS Project From ER schemes to Hypertext Conceptual schemes Selecting Macroentities (objects relevant and independent) Designing Directed Relationships (precise the direction of navigation) Designing Union Nodes and Aggregations (representation of the IS-A relationship)

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The ARANEUS Project 1:N 1:1 Selecting Macroentities (objects relevant and independent) 1:N 1:1 1:1 1:N name type day hour roomNum phone name photo e-mail

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The ARANEUS Project 1:N 1:1 Selecting Macroentities (objects relevant and independent) 1:N 1:1 1:1 1:N name type day hour roomNum phone name photo e-mail

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The ARANEUS Project 1:N 1:1 Designing Directed Relationships (precise the direction of navigation) 1:N 1:1 1:1 1:N name type day hour roomNum phone name photo e-mail

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The ARANEUS Project Designing Union Nodes and Aggregations (representation of the IS-A relationship) 1:N 1:1 1:N 1:1 1:1 1:N name type day hour roomNum phone name photo e-mail

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The ARANEUS Project Department Hypertext Conceptual Scheme type = undergraduate type = graduate name phone photo e-mail 1:N 1:1 day hour roomNum 1:N name type

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The ARANEUS Project From Hypertext Conceptual schemes to Hypertext Logical Design Mapping Macroentities (to pages or lists) Mapping Directed Relationships (to links between pages) Mapping Aggregations (pages + lists + links)

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The ARANEUS Project Mapping Macroentities to pages name phone photo e-mail room ...

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The ARANEUS Project Mapping Macroentities to lists title author date hour room ...

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The ARANEUS Project Mapping Directed relationships to links name phone photo e-mail room ... 1:N 1:1 day hour roomNum 1:N name type

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The ARANEUS Project (Univ. Roma 3) 1 2 3 4 5 6 Dynamic page generation

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Querying the databases (browsing and navigating) a query language to make DB requests a tool for presenting the result of the request: in HTML form in any form What we need:

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The Target Form Expression (TFE) project (Univ. of Keio, Japan) Idea: Extending SQL to add publishing facilities the result of a query is presented in a structured document (HTML, Java, LaTeX, ...) To give a comparison: Allaire's Cold Fusion does not allow grouping or hyperlink generation (necessary for structuring documents)

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The Target Form Expression project GENERATE keyword GENERATE andlt;mediumandgt; andlt;TFEandgt; andlt;mediumandgt; = HTML, LaTeX, Java, Excel, TCLTK, O2C, SQL andlt;TFEandgt; = expression , = tuple connector ! = row connector % = depth (link) operator [ and ] = repeaters [emp.name, emp.salary]! = list of tuples (names, salary) [store.name, [dept.name ! [emp.name]!, [item.name]!]!]%

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The Target Form Expression project Example of a movie database cast

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The Target Form Expression project

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The Target Form Expression project select a category generate html verb(select a category) ! [f.type % [f.year, [f.title % {f.title ! imagefile(f.pict) ! [imagefile(a.face), a.name, a.birth]!}]!]!], from film f, cast c, actor a where f.id = c.film and c.actor = a.id

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The Target Form Expression project generate html verb(select a category) ! [f.type % [f.year, [f.title % {f.title ! imagefile(f.pict) ! [imagefile(a.face), a.name, a.birth]!}]!]!], from film f, cast c, actor a where f.id = c.film and c.actor = a.id

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The Target Form Expression project generate html verb(select a category) ! [f.type % [f.year, [f.title % {f.title ! imagefile(f.pict) ! [imagefile(a.face), a.name, a.birth]!}]!]!], from film f, cast c, actor a where f.id = c.film and c.actor = a.id

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The Target Form Expression project generate html verb(select a category) ! [f.type % [f.year, [f.title % {f.title ! imagefile(f.pict) ! [imagefile(a.face), a.name, a.birth]!}]!]!], from film f, cast c, actor a where f.id = c.film and c.actor = a.id

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The Target Form Expression project The first wives club generate html verb(select a category) ! [f.type % [f.year, [f.title % {f.title ! imagefile(f.pict) ! [imagefile(a.face), a.name, a.birth]!}]!]!], from film f, cast c, actor a where f.id = c.film and c.actor = a.id

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The Target Form Expression project The first wives club generate html verb(select a category) ! [f.type % [f.year, [f.title % {f.title ! imagefile(f.pict) ! [imagefile(a.face), a.name, a.birth]!}]!]!], from film f, cast c, actor a where f.id = c.film and c.actor = a.id

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The Target Form Expression project The first wives club generate html verb(select a category) ! [f.type % [f.year, [f.title % {f.title ! imagefile(f.pict) ! [imagefile(a.face), a.name, a.birth]!}]!]!], from film f, cast c, actor a where f.id = c.film and c.actor = a.id

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The Target Form Expression project INVOKE keyword allow dynamic queries inside queries (recursive queries)

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Classical Database Environment Environment of a classical DBMS: secure environment

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Classical Database Environment Multidatabases - Federated DBMS Cooperative work, ...

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Securing the databases The Internet introduces threats for the DBMS and the users. 4 attacks among the more frequent Interception Modification Fabrication Interruption

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Confidentiality Cannot help a message to be intercepted; The message must not be disclosed; Confidentiality of data (Privacy) Encryption (e.g. Secure Socket Layer - SSL) Interception

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Dangerous behaviours Modification Fabrication

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Dangerous behaviours A user cannot deny having received or sent a message. Non-Repudiation schemas, based on the authentication of user. A user must really be who he claims to be. Authentication of user Authentication certificates delivered by a 'Thrustee'

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Dangerous behaviours Interruption A user cannot help a communication to being cut. Recovery procedures, based on time-outs and logging.

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Securing the databases The iSaSiLk toolbox (Univ. of Vienna) Written in Java Provides cryptography primitives (possibility to implement SSL sockets) Provides authentication primitives Provides certificate management Free for use for academic partners (not free for industry)

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Transactions in the Internet Transactions are a very common tool in databases They provide isolation of concurrent activities They are fault tolerant processes They have been extensively studied in distributed environment But They lack security and scalability in the Internet

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Example in Electronic Commerce Internet

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Example in Electronic Commerce Internet I want...

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Example in Electronic Commerce Internet the same shirt as Sandra Bullock's in 'The Net', and...

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Example in Electronic Commerce Internet the same hat as Ingrid Bergman's in 'Casablanca'!

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Example in Electronic Commerce Internet

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Example in Electronic Commerce Internet ACID Atomicity Consistency Isolation Durability

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Example in Electronic Commerce Internet ACID Atomicity Consistency Isolation Durability Secure Confidentialty Authentication Non-Repudiation

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Example in Atomic File Transfer Protocol Internet Sofware update Server A Server B System administrator

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Example in Atomic File Transfer Protocol Internet Server A Server B System administrator

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Example in Atomic File Transfer Protocol Internet Server A Server B System administrator

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Example in Atomic File Transfer Protocol Internet Server A Server B Installation application

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Example in Internet Aided Manufacturing Internet New extension card for PC

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Example in Internet Aided Manufacturing Internet New extension card for PC Printed circuit manufacturer

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Example in Internet Aided Manufacturing Internet New extension card for PC Printed circuit manufacturer Electronic component supplier

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Example in Internet Aided Manufacturing Internet New extension card for PC Printed circuit manufacturer Electronic component supplier

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Example in Internet Aided Manufacturing Internet Integrator Towards workflows

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Transactions in the Internet Transaction Internet Protocol (TIP) Corba OTS (Object Transaction Service) X/Open DTP (Distributed Transaction Processing) Related work on transactions:

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Workflows on the Internet A workflow business process:

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Workflows on the Internet Process (separation of business logic from function logic) Organization (who is doing what) Infrastructure (what has to be done manually, with computer, ...) 3 levels in a workflow:

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Workflows on the Internet Flowmark Flowman InConcert Staffware ViewStar ...

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Resume of part 1 We know how to modelize and represent a database We know how to query the database and visualize the results We are aware of security and fault-tolerance problems