Wednesday, September 21, 2005

Limitations of MS Access

REFERENCE: http://www.codeguru.com/forum/archive/index.php/t-235929.html
There is an article Microsoft Access 2000: Choosing between MSDE and Jet (http://www.microsoft.com/sql/techinfo/deployment/70/msdejet.asp) which lists all the limitations of Access database in the Word file (http://www.microsoft.com/sql/techinfo/deployment/70/Access2000MSDE.doc).
Here is extract:
"Appendix B: Access/Jet (.mdb) Specifications

File size (.mdb filetype) 2 GB
No. of objects in a database 32,768
Modules 1,000
Number of characters in an object name 64
Number of characters in a password 14
Number of characters in a user name or group name 20
Number of characters in a table name 64
Number of characters in a field name 64
Number of fields in a table 255
Number of open tables 2048.
Table size 1 gigabyte
Number of characters in a Text field 255
No. of characters in a Memo field (data entered via UI) 65,535
No.of char. in a Memo field (data entered programmatically) 1 gigabyte
Size of an OLE Object field 1 gigabyte
Number of indexes in a table 32
Number of fields in an index 10
Number of characters in a validation message 255
Number of characters in a validation rule 2,048
Number of characters in a table or field description 255
Number of characters in a record 2,000
Number of characters in a field property setting 255"

Thursday, September 01, 2005

Number of users Access can Accomodate

http://www.dbforums.com/archive/index.php/t-1079077.html
I agree Access is a very easy to start with database, but here are the
limitations to what Access can do:

1. The theoretical maximum number of concurrent users in an Access database
is 255. However, this figure is just the maximum
number possible, and you are more likely to find that the maximum number of
users is about 50-100, although depending on your
design, this might be less. This should certainly be borne in mind when
starting to design a database, as it is almost guaranteed that
although the initial brief called for only 15 users, after a year of
operation there will probably be twice that using the database.
Therefore over-engineering is required.

2. Also, Access isn't configured to run as a client/server database, so it
isn't optimized for running over a network. A true client/server
application will only call the data from the server to the client that are
needed. Therefore, you will probably see some network
performance degradation.

3. Access is also limited to how much data it can store. In Access 97, this
is 1 Gigabyte per database, and in Access
2000 it is 2Gb, although you can have multiple databases used to store
information in.

I believe this info is relevant for you to decide. I strongly recommmend
that if you haven't yet started with your app design,
switch to SQL as backend, and frontend with something as VB, that gives you
more flexibility and a far better UI.