Database Limitations


As you design your database, you should keep in mind the following limitations:

  • A table can have up to 255 fields.

  • A table can have up to 32 indexes.

    Note 

    Keep in mind that defining relationships with Referential Integrity turned on creates one additional index in each participating table that counts toward the 32-index limit per table.

  • A multiple-field index can have up to 10 fields. The sum of the lengths of the fields cannot exceed 255 bytes.

  • A row in a table, excluding memo fields and ActiveX objects, can be no longer than approximately 4, kilobytes.

  • A memo field can store up to 1 gigabyte of characters, but you can’t display a memo larger than 64 kilobytes in a form or a datasheet.

    Note 

    Clearly, if you try to store a 1-gigabyte memo (which requires 2. gigabytes of storage because of double-byte character set support) or a 2-gigabyte ActiveX object in your database file, your file will be full with the data from one record.

  • An ActiveX object can be up to 2 gigabytes in size.

  • There is no limit on the number of records in a table, but an Access 2007 database cannot be larger than 2. gigabytes. If you have several large tables, you might need to define each one in a separate Access database and then attach them to the database that contains the forms, reports, macros, and modules for your applications. See Chapter 6, “Importing and Linking Data,” for details.

Now that you’ve started to get comfortable with creating databases and tables, you can read the next chapter to learn how to make modifications to existing tables in a database.




Microsoft Office Access 2007 Inside Out
MicrosoftВ® Office Access(TM) 2007 Inside Out (Microsoft Office Access Inside Out)
ISBN: 0735623252
EAN: 2147483647
Year: 2007
Pages: 234

Similar book on Amazon
Access 2007: The Missing Manual
Access 2007: The Missing Manual
Microsoftu00ae Office Access(TM) 2007 Step by Step (Step By Step (Microsoft))
Microsoftu00ae Office Access(TM) 2007 Step by Step (Step By Step (Microsoft))
Microsoft Office Access 2007 Forms, Reports, and Queries
Microsoft Office Access 2007 Forms, Reports, and Queries
Alison Balter's Mastering Microsoft Office Access 2007 Development
Alison Balter's Mastering Microsoft Office Access 2007 Development

flylib.com © 2008-2017.
If you may any questions please contact us: flylib@qtcs.net