I have an XML doc like follows which is populated all day long by a client, about 5 records per minute. The client is responsible for populating the XML File with data and I'll read the data (this is a continual process all day long) and display some calculated results on an HTML page.
<data field1="123" field2="456" field3="789" .... about 60 attributes of type "double", could be up to 500
<data field1="198" field2="745" field3="124"
....... many records
I want to read the last e.g. 3 <data> records on the list and do an average of each value about every minute within the "page_load" method of the vb code. The asp.net page is set to refresh every 60 seconds in the <meta> tag. Some business logic is done on the values before they are display on the HTML page.
The XML file will get very large with all the readings - should the records be moved to another file for archiving as they'll need to be recalled in future?
Please advise the best method for my problem and give a code sample to read the last few rows in the list specific to my problem and do an average on them (and how to write the values to another file if this is what should be done)