MS Access size limit


ODBC errors are generated every time the program attempts to save information to the database.


The reason for these problems is most probably that the 2 GByte size limit of your MS Access connected database has been reached. This can be confirmed in Windows Explorer by checking the file size of the MS Access data file (extension .MDB) in the BioNumerics database directory.

When a connected database was set up in a BioNumerics version prior to 6.0, the option Store trace files in database was checked by default. Sequence trace files are relatively large, so they quickly fill up the database. For applications such as MLST, in which large numbers of sequences are assembled from trace files, we recommend to use SQLite (available from BioNumerics version 7.5 on) or a database management software (DBMS) such as SQL Server, MySQL or Oracle.

Alternatively, if you prefer to continue using MS Access, you should uncheck the option Store trace files in database in the Connected database dialog box and always save the trace files in the same directory on your computer or on a network drive (from version 7.0 on, a copy is automatically saved in the source files directory). A technical support document is available with step-by-step instructions on reducing the size of the MS Access data file by exporting trace files saved in the connected database and restoring them as files in a directory of your choice. Please contact our support team to obtain this document.

To restore the functionality of the database, it will be necessary to compact the database file first. This can be done by opening the database in MS Access and selecting “Compact & Repair database” (under “Database tools”). When MS Access is not installed on your computer or in rare cases where the .MDB file is corrupted and cannot be opened in MS Access anymore, a standalone tool such as JetComp (see might be required to compact and repair the database directly via the Microsoft Jet Engine.


Applicable for: 
Version 3.5 - 8.0