I am a little unclear about your message but the first thing I would do is find out exactly what is happening on your network. Find out what your traffic patterns are and then what is causing them. To help in this you can look into MRTG (http://people.ee.ethz.ch/~oetiker/webtools/mrtg/). That will show you graphically the traffic coming into an interface and out of an interface. It can show the cpu, memory, errors etc of your network devices. If there is a MIB that your device supports, MRTG can grab it. That will let you know if the slow down is traffic related. Doesn't take long to install and configure either. You can also look into Qcheck to measure your actual throughput on your links. Both great toold and both free.
If you find it's traffic related and you want other user traffic to have priority over the dbase traffic, you can look into traffic shaping to give one type of traffic priority over another.
Here is a sample of traffic shaping: http://www.cisco.com/en/US/products/sw/iosswrel/ps1835/products_configuration_guide_chapter09186a00800bd8ef.html
Here is a sample of traffic policing: http://www.cisco.com/en/US/products/sw/iosswrel/ps1839/products_feature_guide09186a0080087b04.html
Here is a sample of traffic queuing: http://www.cisco.com/en/US/products/sw/iosswrel/ps1830/products_feature_guide09186a0080087b13.html
But first you have to find out what's going on. Tools you can use are MRTG, sniffers, Qcheck, syslog and if you have to access-lists with the log keyword or ip accounting (careful with this one due to the increased CPU load on the router) to find out the mem/cpu/errors/traffic/etc of your network devices.
Hope it helps.
Steve