Drew Wutka
DWUTKA at Marlow.com
Tue Feb 6 09:34:27 CST 2007
Again, it depends on the design of the front end. Drew -----Original Message----- From: accessd-bounces at databaseadvisors.com [mailto:accessd-bounces at databaseadvisors.com] On Behalf Of Dan Waters Sent: Tuesday, February 06, 2007 8:57 AM To: 'Access Developers discussion and problem solving' Subject: Re: [AccessD] Connections and Performance Hi Drew, Do you know how many FE clients could maintain that type of connection to a BE at the same and still have reasonable performance? Does anyone have experience with this configuration? Dan Waters -----Original Message----- Subject: Re: [AccessD] Connections and Performance I believe there is only one connection between a front end and back end. In fact, many databases have better performance when the connection is maintained through a 'linked table'. Create a dummy table (one field, no records), called tblLink. Create a form bound to that table, and open that form, hidden, on startup. That keeps the 'connection' live while the user is in the database. I know in Access 97 that process was recommended in the help files under 'splitting a database'. Drew -----Original Message----- Subject: Re: [AccessD] Connections and Performance Thanks Drew, I have asked everyone at my customer's site to close the screens they're not using (these are bound), but told them they can stay logged in because the main screen is not bound. We'll see if that helps. If not then I will need to start timing out the bound forms. I still don't know what is the definition of one connection. Is one bound form a connection? Is a FE with any number of bound forms a connection? Or is a connection defined by the periods of time when data transfer is taking place between a FE and BE? Or . . . ? Thanks for teaching me! Dan Waters -----Original Message----- From: accessd-bounces at databaseadvisors.com [mailto:accessd-bounces at databaseadvisors.com] On Behalf Of Drew Wutka Sent: Monday, February 05, 2007 4:06 PM To: Access Developers discussion and problem solving Subject: Re: [AccessD] Connections and Performance Most 'articles' that 'document' Access performance are doing so based upon poorly designed systems. You have to design your system based on system requirements. If you are going to have 1 to 5 users, you can keep everything bound, and be reasonably assured that things will work well. If you are talking 5 to 30 users, now it's time to pick up some of the slack. Timeout forms and reports that are going to tie up db connections. 30 to 100 users, you better start thinking unbound. 100+ users, better start thinking about something other then Access as a front end (I would recommend ASP). The point is that JET, as a db system, can handle a lot, but Access, as a Front End provides more bells and whistles that tax the backend more. Case in point, we have our production database in Oracle, on it's own honking box. Huge server, loads of memory and disk space, but when certain things are run, even that system gets taken to It's knees. Drew -----Original Message----- From: accessd-bounces at databaseadvisors.com [mailto:accessd-bounces at databaseadvisors.com] On Behalf Of Dan Waters Sent: Friday, February 02, 2007 10:13 PM To: 'Access Developers discussion and problem solving' Subject: Re: [AccessD] Connections and Performance Drew, I read this somewhere - either in MS documentation or in a book where I believe the author. Here's the reason I was asking: At a certain customer site, they experienced a dramatic performance slowdown at a time when about 10 people were logged on concurrently. Each client PC has it's own FE. I know that they open the system and leave the process screens open, all of which are bound. I want to suggest that they remember to close the process screens so that just the main screen is open, which is not bound. This way a fewer number of connections are being used at any one time and performance would probably be acceptable. This particular customer, I believe, does not have a very good network, so that is part of the problem. But that's unlikely to get improved, so I wanted to provide at least a partial solution, hence my question. I've also heard that a connection is made not based on whether a form is open and bound, but on whether or not there is data traffic between to and from a table, which only takes a small part of a second. So what causes the performance slowdown when only 10 client PC's are logged on, and what could be done to improve this? Dan Waters -----Original Message----- From: accessd-bounces at databaseadvisors.com [mailto:accessd-bounces at databaseadvisors.com] On Behalf Of Drew Wutka Sent: Friday, February 02, 2007 9:26 AM To: Access Developers discussion and problem solving Subject: Re: [AccessD] Connections and Performance Where are you getting these numbers. Access can have up to 255 connections. Drew -----Original Message----- From: Dan Waters [mailto:dwaters at usinternet.com] Sent: Friday, February 02, 2007 8:45 AM To: 'Access Developers discussion and problem solving' Subject: Re: [AccessD] Connections and Performance Access has the potential for 8 simultaneous connections, but 3 of them are reserved for the system's use. That leaves five for users. Dan Waters -----Original Message----- From: accessd-bounces at databaseadvisors.com [mailto:accessd-bounces at databaseadvisors.com] On Behalf Of JWColby Sent: Friday, February 02, 2007 8:02 AM To: 'Access Developers discussion and problem solving' Subject: Re: [AccessD] Connections and Performance >But, the connection limit for one BE is 5 FE's. What does this mean? I have never heard of any such thing. John W. Colby Colby Consulting www.ColbyConsulting.com -----Original Message----- From: accessd-bounces at databaseadvisors.com [mailto:accessd-bounces at databaseadvisors.com] On Behalf Of Dan Waters Sent: Friday, February 02, 2007 8:58 AM To: 'Access Developers discussion and problem solving' Subject: [AccessD] Connections and Performance I've read several times that maintaining a connection between a FE and a BE will increase the performance of the FE because it doesn't need to reconnect before transferring data. The connection here would be a bound form connected by a table link to a table in the BE. But, the connection limit for one BE is 5 FE's. So, will maintaining connections on more than 5 FE's reduce performance? Seems logical, but I was wondering if this is correct or is there more to it? Thanks! 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