Access to databases of interest.

Chest Pain Dataset

1. There is a subset of the Children's Hospital medical record system containing about 300 patient records in an Oracle 7.3.2 database on the machine Gray.lcs.mit.edu. This is actual patient data downloaded from Children's Hospital in Boston, which has been "scrubbed" to remove identifying information about the patients. Nevertheless, treat the data as confidential, because potential errors in scrubbing or others' abilities to correlate apparently innocuous facts about these patients with other knowledge could lead to compromise. In particular, do not leave the data or any data extracted from it in places where others could gain access to it.

There is an incomplete description of the data model available.

To access these data from a PC running Windows95 or WindowsNT, the following components need to be installed:

  1. Oracle software from CD labelled Workgroup Server 7.3.2.1.1 NT. This disk contains the full server software for Oracle running under NT, but for our purposes the stuff of interest is the client software for either 95 or NT, depending on your workstation setup.
  2. One of the components that is installed by the above setup should be SQL*Net V2. This needs to be configured by running the program "SQL Net Easy Configuration" (under he Start menu). You need to select "Add Database Alias" and do the following:
  3. Oracle's ODBC (Open Database Connectivity) drivers must also be installed in order to give you convenient access to the database. These may be obtained from Oracle's Web site, or from anonymous FTP on medg.lcs.mit.edu/pub/6.872/ORACLE_ODBC. That directory contains two files, n116315.exe, and runme.bat. (The .exe file is about 10MB in size, so don't try this over a slow modem!) Download them both and run the latter. It will expand the former into three subdirectories that install the ODBC drivers for Windows95, Windows3.1 and WindowsNT/x86, respectively. From the appropriate subdirectory, run Setup.exe. Tell it just to install the ODBC drivers; the rest of what it proposes should already be in place.
  4. You then need to configure the ODBC driver. From the Oracle menu under your Start menu, select "32-bit Administrator" (euphoneous, no?). When it lists data sources, select "Add...". Select the "Oracle73 driver." In the next dialog box, for Data Source name type OCHDB, for SQL*Net String type CHDB (from step 2, above). (Description is for your pleasure.)
  5. You can test out your installation thus far by using the 32-bit ODBC Test program under the Oracle hierarchical menu. When you Connect, choose OCHDB and type your Oracle User Name and Oracle Password. (Note: You must obtain these from the instructor before you can connect to the Oracle database!)
  6. A more capable way to browse the database than by using the above test program is to set up the Microsoft Access database program to connect to OCHDB. This lets you use the facilities of Access to view the data, prepare reports, design forms, run queries, etc. Unfortunately, the "standard" installation of Access (which is part of Microsoft Office Professional) does not install the ODBC drivers needed by Access. You need to select "custom install" and tell it to do so.
  7. In Access, you need to create a new database, Then select File/Get External Data/Link Tables..., and under Files of type, select ODBC Databases. Then select or type OCHDB for Select Data Source. This will ask you to log on to Oracle, so use your Oracle User Name and Oracle Password. You then can select all of (or a subset of) the tables in the next selection list. You will get a handout showing the tables and fields in them. Access then maps each selected Oracle table to an Access table that it creates. In this process, it will ask you what are the primary key(s) of each table. Once this process is completed, you can use all of Access' facilities to explore this database.
  8. Other means of accessing the Oracle database involve programming in various scripting or programming languages. Some of these require installation of additional "bridging" software. For example, Java access requires JDBC, which in turn uses ODBC, which in turn uses SQL*Net! We do not have instructions (or licenses) for how to use all these, but here is a list of some possibilities:

Any of these methods can be used, in turn, with various Web server technologies to build Web-based applications. These are challenging implementation problems.