David, Thank your for the your thoughts. I have psql installed and I am currently trying to use pgADMIN III. I have used it to make and drop Databases and tables. I have not yet successfully built a table from SQL. I have taken one of my Excel tables and used it to build a CREATE table script. I have built a couple dozen small scale databases in Access and I have read a lot about normalization. But I am not sure how far to take it. I am intrigued by the idea of using queries and views to de-normalize data. But I don't have a clue as to a process. I appreciate your comment on designing for efficient representation rather than use cases. I am guessing that means normalization? ray -----Original Message----- From: David Johnston [mailto:polobo@xxxxxxxxx] Sent: Sunday, March 20, 2011 9:05 AM To: 'ray'; pgsql-general@xxxxxxxxxxxxxx Subject: RE: Database Design for Components and Interconnections Ray, You seem to have a fairly good understanding of the model you are working with. I'd suggest simply finding some technical SQL resources, install PostgreSQL, and fire away. Learn by doing. When doing the design focus on minimizing the amount of non-key repetition that you model (find and read stuff regarding database normalization). You can use queries and views to de-normalize the data as needed for processing. While you want to keep in mind HOW you plan to use the data it is more important to focus on simply efficiently representing the data using the model. You can never fully predict how you will want to use data but if it is modeled well most use cases can be implemented without too much difficulty. If you cheat to make working with a specific use case easier you are likely to find that, in the future, a new use case has to deconstruct the data before it can be used. It is much harder to deconstruct data than to construct more complex data from simpler parts. Lasty, remember that learning takes time and energy (though the bright-side is that actual cash outlay is minimal if you can provide enough of the other two items) David J. -----Original Message----- From: pgsql-general-owner@xxxxxxxxxxxxxx [mailto:pgsql-general-owner@xxxxxxxxxxxxxx] On Behalf Of ray Sent: Sunday, March 20, 2011 12:40 AM To: pgsql-general@xxxxxxxxxxxxxx Subject: Database Design for Components and Interconnections I am looking for some help in database design. I would like to design a database to help design alternative designs of a basic electronic circuit design. I have a list of components that will be interconnected for a basic design. Additional components and associated connections are identified for different alternatives. The connections have properties that must be managed. The typical use is to implement a new design where a specific set of components is identified and the associated interconnects need to be managed. Additionally, these two sets of data will be copied to another application for analysis. The connection information is a matrix where the row and column 'labels' are elements of the components table. The matrix elements define the interconnections between the components. In the simplest case, the interconnection matrix elements are just either -1, 0, or 1, defining whether or not there is a connection between the two components and the direction of the connection. In the more realistic cases, there are many properties of each interconnection so this is a three dimensional matrix. As for performance, this database will be accessed by at most 20 people at one time where they are addressing disjoint properties. The number of components will be a couple thousand. The average number of interconnections of any one component to other components is 6 so the matrix may be considered sparse. I usually use a spreadsheet for the component definitions and multiple spreadsheets (tabs) for each of the tables in the third dimension. Then save the needed interconnection info as a CSV file for import into other applications. I will appreciate any suggestions, insights, questions and comments. Thanks, ray -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
