Calculating Access 97 size and handling of text fields

[kuhni]

Hi everybody!

After searching newsgroups for a couple of hours, I now try asking
directly (running the risk of asking again the same question). My
problem is to predict when the size of the database (1GB I expect) is
over 1GB by calculating the maximal number of data sets (tuple) added:

1. Is the following calculation for estimating the mdb file size in
Access 97 correct:
1 integer field = 4 Byte
1 text field (10 characters only permitted) = 10 x 1 Byte (Assumption:
Unicode 2 Byte after compression only 1 Byte) = 10 Byte
+ a certain amount of Access overhead (that's not my problem by the
way)

2. What happens to text fields internally when there is not all memory
used? E.g. text field (size: 255 characters) with no entry or only one
character. Is the full memory reserved anyway or does Access 97
recognise that no data is in and doesn't use all the memory?

THANK YOU SO MUCH!

All the best,
Stephan Kuhnert

[Douglas J. Steele]

Access only uses as much space for text fields as is required. This is
easily proven. Create a table that has 10 text fields, each of 255 bytes. In
theory, that exceeds the allowable row size, however, you won't get an error
until after you try to store the 2001st character.

Yes, an Integer in Access is 4 bytes.

I don't believe Access 97 supports Unicode, so that's a non-issue.

Don't forget that indexes take up part of the 1Gb.

--
Doug Steele, Microsoft Access MVP
http://I.Am/DougSteele
(no e-mails, please!)

"kuhni" <st************ @gmx.de> wrote in message
news:88******** *************** ***@posting.goo gle.com...

Hi everybody!

After searching newsgroups for a couple of hours, I now try asking
directly (running the risk of asking again the same question). My
problem is to predict when the size of the database (1GB I expect) is
over 1GB by calculating the maximal number of data sets (tuple) added:

1. Is the following calculation for estimating the mdb file size in
Access 97 correct:
1 integer field = 4 Byte
1 text field (10 characters only permitted) = 10 x 1 Byte (Assumption:
Unicode 2 Byte after compression only 1 Byte) = 10 Byte
+ a certain amount of Access overhead (that's not my problem by the
way)

2. What happens to text fields internally when there is not all memory
used? E.g. text field (size: 255 characters) with no entry or only one
character. Is the full memory reserved anyway or does Access 97
recognise that no data is in and doesn't use all the memory?

THANK YOU SO MUCH!

All the best,
Stephan Kuhnert

[Ed Robichaud]

If you know now that your data will exceed 1 gig, then Jet is not the tool
for you. Try Oracle or SOL.
-Ed

"kuhni" <st************ @gmx.de> wrote in message
news:88******** *************** ***@posting.goo gle.com...

Hi everybody!

After searching newsgroups for a couple of hours, I now try asking
directly (running the risk of asking again the same question). My
problem is to predict when the size of the database (1GB I expect) is
over 1GB by calculating the maximal number of data sets (tuple) added:

1. Is the following calculation for estimating the mdb file size in
Access 97 correct:
1 integer field = 4 Byte
1 text field (10 characters only permitted) = 10 x 1 Byte (Assumption:
Unicode 2 Byte after compression only 1 Byte) = 10 Byte
+ a certain amount of Access overhead (that's not my problem by the
way)

2. What happens to text fields internally when there is not all memory
used? E.g. text field (size: 255 characters) with no entry or only one
character. Is the full memory reserved anyway or does Access 97
recognise that no data is in and doesn't use all the memory?

THANK YOU SO MUCH!

All the best,
Stephan Kuhnert