Oracle Pro Tips, Trends & Technology eXTRA Pinnacle Publishing http://www.pinnaclepublishing.com Issue 3.8 May 28, 2002 TABLE OF CONTENTS 1) Pop Quiz (answer at the end) 2) Did You Know... 3) Oracle News 4) Java Series 5) Answer to the Pop Quiz --------------------------------------------------------- 1) POP QUIZ (answer at the end) --------------------------------------------------------- a. In Oracle8 and Oracle9, what types of LOBs (large objects) are supported? b. What's the difference between an "internal" LOB and an "external" one? c. How many segments are created for each LOB column in Oracle? d. If a table contains one CLOB column and one BLOB column, what's the number of segments created for that table? e. How does one find out the segments that belong to an LOB? f. What are the components of a CLOB? --------------------------------------------------------- 2) DID YOU KNOW... --------------------------------------------------------- * that Oracle has created a Web-based conference/chat group called CTO Summit? According to Oracle, the "CTO Summit is a special online event that analyzes technology trends and brings you the information you need to make the right choices for tomorrow." Better still, you can for free! Check out the following link for details: http://www.oracle.com/events/ctosummit/index.html?overview.html Note that for some of these Oracle links, you'll have to first register with Oracle before you can access them. For your free registration, go to http://technet.oracle.com/. As I had mentioned in previous articles, once you've registered, you can access Oracle's online documentation at: http://technet.oracle.com/docs/products/oracle9i/content.html ********************************************************* eTouchDB V2.1 Add a database capability to your Web site. eTouchDB allows the Web user to view, edit, add, delete, and even filter through a database using a basic Internet Web browser. Features include: compatibility with current Web publishing techniques, use as little as two lines of ASP code, eTouchDB writes the HTML for your database on the fly and allows users to view, edit, or even modify your database from anywhere in the world. eTouchDB supports these database formats: Oracle, Microsoft Access, Microsoft Excel, Microsoft SQL Server, Sybase, Ingres, DB2, Informix, dBASE, Foxpro, Paradox, Btrieve, Clipper, CSV, and Tab Delimited Text file. http://www.componentsource.com/product.asp?SC=Pinna&PO=511115&option=&MTC=XX ********************************************************* --------------------------------------------------------- 3) ORACLE NEWS --------------------------------------------------------- The Oracle Applications Users Group conference was recently held in Toronto. The next one will be held in September. Check out the conference details at: http://www.oaug.org/ * * * * If you like figures, you may be interested in Oracle database technology market share for ERP software. Apparently, Oracle is the database of choice for organizations that implement SAP, Siebel, and Peoplesoft. Find out more at the following URL: http://www.oracle.com/features/9i/index.html?t1db_facts.html As we all know, vendors tend to highlight statistics that favor their products. That's why the above figures were readily available on Oracle's Web site. Wired magazine (http://www.wired.com/) recently reported that, in terms of the overall database market, which includes relational and non-relational databases, IBM has taken the lead, overtaking Oracle with US$3.06 billion in database revenue. Oracle has sales of US$2.97 billion a year, slipping to the number two spot. Nevertheless, Oracle remains "leader of the relational database software segment that accounts for 80 percent of the overall $8.84 billion database market." Find out more at: http://www.wired.com/news/business/0,1367,52357,00.html * * * * Finally, if you're interested in finding out potential security issues in Oracle products, please check out the following URL: http://www.cert.org/advisories/CA-2002-08.html It discusses the "multiple vulnerabilities in Oracle Application Server and Oracle Database...," which include "buffer overflows, insecure default settings, failures to enforce access controls, and failure to validate input. The impacts of these vulnerabilities include the execution of arbitrary commands or code, denial of service, and unauthorized access to sensitive information." --------------------------------------------------------- 4) JAVA SERIES --------------------------------------------------------- My colleague Jim Skehill has been very busy during the past couple of weeks building a Java prototype for a time-entry and project-tracking application. As a result, he's unable to contribute a Java article this week. The good news is that we'll ask him to share his war stories on building industrial Java applications using Oracle 9iAS technology! --------------------------------------------------------- 5) ANSWER TO THE POP QUIZ --------------------------------------------------------- a. In Oracle8 and Oracle9, what types of LOBs (large objects) are supported? Starting from Oracle8, four types of LOBs are supported, namely: -- CLOB, which contains single-byte character data -- for example, a resume -- BLOB, which contains binary data -- for example, a Microsoft Word document -- NCLOB, which contains fixed-width multi-byte character data -- for example, a resume in Chinese -- BFILE, which contains binary data stored outside the Oracle database; Oracle simply contains a "pointer" to the operating system for read-only access -- for example, a JPEG image file in the operating system can be "read" into the database for display. b. What's the difference between an "internal" LOB and an "external" one? CLOB, BLOB, and NCLOB are known as "internal" LOBs, whereas BFILE is an "external" LOB. Internal LOBs require space to be allocated within the Oracle database for storage. On the other hand, an external LOB is physically stored outside Oracle; Oracle simply stores the pointer, not the entire BFILE object. Because of this, the BFILE operating system file is excluded from Oracle's backup and recovery facility. For instance, a database export won't be able to export the BFILE content. c. How many segments are created for each LOB column in Oracle? Two segments are created: one data segment and one index segment. d. If a table contains one CLOB column and one BLOB column, what's the minimum number of segments created for that table? Five: one segment for the table data, and two segments for each of the LOB columns, bringing the total to five. e. How does one find out the segments that belong to an LOB? SELECT * FROM user_lobs; f. What are the components of a CLOB? i. LOB data values: data that is stored ii. Locator: A pointer to the data location. It's stored in line with the other data of its row iii. LOB index: This is created implicitly and is used to find the LOB data --------------------------------------------------------- Well, that's it for this week. I welcome your feedback, input, tips, suggestions, Web sites, and other Oracle- related news. If you send me something, please let me know whether I can use your name with your comments. I apologize in advance if I don't respond personally to each of your questions or suggestions, but I'll get to as many as I can in the eNewsletter if not personally. Garry Chan, Editor Database Architect mailto:GChan@ProcaseConsulting.com This eNewsletter is brought to you compliments of Pinnacle Publishing, Inc. Copyright(c) 2002 http://www.pinnaclepublishing.com All rights reserved.