Optimizing Microsoft Access Performance

Summary

The information in this article applies to LIMS 1.x and Access 2.0.

The faster Microsoft Access runs, the faster LIMS runs. Follow the tips in this article to improve overall system performance.

More Information

Follow the suggestions below to increase the performance of Microsoft Access and LIMS:

1. Increase RAM, if possible. While Access will run on workstations with as little as 8 MB, the practical minimum for Access and LIMS is 16 MB. Adding additional RAM will improve performance significantly.

2. Set Microsoft Windows Virtual Memory. Make sure the Virtual Memory swap file setting is large enough and permanent rather than temporary. Use the 386 Enhanced icon of the Windows Control Panel to view and update the swap file settings.

3. Set buffers to at least 40. Set the buffers setting in the CONFIG.SYS file to at least 40 to make it easier for Access to perform operations on large database files.

4. Defragment your hard disk and compact the database. If applicable (not a concern on some network operating systems such as NetWare), use a disk defragmenting utility (e.g. MS-DOS Defragmenter) to periodically defragment the hard disk where LIMSDATA resides. Periodically compacting both LIMSCODE and LIMSDATA will remove fragmentation within the file, reduce the size of the file, and restore optimal performance.

5. Don’t use Windows wallpaper (full-screen background) bitmaps on a low-memory workstation.

6. Adjust the [ISAM] settings in LIMS.INI. The two settings that have the most impact on performance are MaxBufferSize and ReadAheadPages. Keep in mind that the optimum value for a setting can vary by workstation and is dependent on how much memory is available at any given time.

MaxBufferSize. This sets the maximum size of the Jet database engine’s internal cache and is measured in kilobytes. The default setting is 512. You can set it to any value from 18 to 4096.

ReadAheadPages. This sets the number of 2K data pages the Jet database engine reads ahead when doing sequential page reads. The default setting is 16. You can set it to any value between from 0 to 31.