> Does anyone have any statistics or even subjective feelings about the > efficiency of using query on query in CF5? > > We're using the Linux version, and are considering using it more > extensively now that we've worked out our data server is extremely > taxed. If it's faster than Interbase at queries I guess it could be a > big resource saver....
I expect some MM people on this list will respond but I thought I would throw in an opinion..... Given that CF5 is still interpretted, I would say that QofQ in CF5 would be slower than accessing the database directly. Remember that CF can cache queries and you should look at this possibility first. Ultimately, though, the data still has to come from your database server - and also has to (possibly) be written back there. If, in the end, you just have lots of requests going to the database that need up-to-minute answers (i.e. CF caching is not an option) then you have to upgrade your DB Server. I would take the statement you made of "our data server is extremely taxed" as a hint that it is time to upgrade. It is unlikely that anything you do will reduce the load on your database server enough to make a difference if it is already at threshold. Even in CFMX (which compiles to Java for execution), QofQ is unlikely tol be as fast at executing queries than the native database you are connecting to. That ignores the network overhead for transmitting the query results (but you can always solve that by upping your network bandwidth between your CF Server and Database Server). You might improve performance on the CF Server end by caching your data there locally and performing QofQ. But this will mainly be because you are saving the time it takes to transmit the results moreso than because you are executing the query on the CF side. I am just guessing here but I believe the SQL "engine" in CFMX is mainly a "brute force" approach equivalent to a full table scan in a database. You can't create indexes to improve performance because the "tables" are only temporarily available. I also doubt if there is an execution plan generated to try and optimise the process. I generally use QofQ for "variations" on reporting against a result set. Meaning that you sometimes want to just do one query and present several "views" of that data. This generally means that I just filter the data I have loaded with a WHERE clause and possible do some aggregations. Everything else I do directly to the database - either through views or direct table access. Gary Menzel Web Development Manager IT Operations Brisbane -+- ABN AMRO Morgans Limited Level 29, 123 Eagle Street BRISBANE QLD 4000 PH: 07 333 44 828 FX: 07 3834 0828 If this communication is not intended for you and you are not an authorised recipient of this email you are prohibited by law from dealing with or relying on the email or any file attachments. This prohibition includes reading, printing, copying, re-transmitting, disseminating, storing or in any other way dealing or acting in reliance on the information. If you have received this email in error, we request you contact ABN AMRO Morgans Limited immediately by returning the email to [EMAIL PROTECTED] and destroy the original. We will refund any reasonable costs associated with notifying ABN AMRO Morgans. This email is confidential and may contain privileged client information. ABN AMRO Morgans has taken reasonable steps to ensure the accuracy and integrity of all its communications, including electronic communications, but accepts no liability for materials transmitted. Materials may also be transmitted without the knowledge of ABN AMRO Morgans. ABN AMRO Morgans Limited its directors and employees do not accept liability for the results of any actions taken or not on the basis of the information in this report. ABN AMRO Morgans Limited and its associates hold or may hold securities in the companies/trusts mentioned herein. Any recommendation is made on the basis of our research of the investment and may not suit the specific requirements of clients. Assessments of suitability to an individual?s portfolio can only be made after an examination of the particular client?s investments, financial circumstances and requirements. --- You are currently subscribed to cfaussie as: [EMAIL PROTECTED] To unsubscribe send a blank email to [EMAIL PROTECTED] MXDU2004 + Macromedia DevCon AsiaPac + Sydney, Australia http://www.mxdu.com/ + 24-25 February, 2004
