'have them log into a separate table per sensor.' Eughhhh. I'm not even going to start explaining why not. Just don't!!
'The main question I have is whether it would be better to have all these sensors log into one table,' Yep. Give each sensor an sensor_ID, have a sensor_ID column in the table, and index the table properly. Your queries will be simpler and much faster than querying upto 100 tables!! HTH, Martin. -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Chris Stebbing Sent: 11 June 2008 07:29 To: Delphi DB List Subject: Database Design Question Hi All, I have a question on database design if I may. The application that I will be working on is an industrial one where we will be logging data from a number of different sensors all at differing rates. The "current" data value is used to initiate actions and is always held in memory, but past data is most commonly graphed regularly. By far the largest amount of data is generated by logging these sensors, and the most common use for this data is simply graphing. An installation could range anywhere from 5 sensors to 100 sensors. The main question I have is whether it would be better to have all these sensors log into one table, or have them log into a separate table per sensor. The amount of data can build up quite an amount over time, and filtering one large table (or querying one large table) takes an amount of time. Having the data already separated by sensor would be a huge head start. Thanks for any comments and my apologies if this question is out of line here. Regards, Chris. _______________________________________________ Delphi-DB mailing list Delphi-DB@elists.org http://lists.elists.org/cgi-bin/mailman/listinfo/delphi-db
