Field Length Question

[Wayne]

Is the storage space requirement of a text field determined by the
field size that has been set or by the actual amount of text stored in
the field?

[Allen Browne]

It's the actual number of characters in the field that determines how much
disk space is used.

Internally, Access uses pointers to manage the saved data, so a Text field
defined at 255 characters does not use up 255 bytes (double for Unicode) on
the drive, unless you actually type 255 characters into it.

Where it does make a difference is the buffer Access uses to hold and edit
the current record(s.) That's limited to 2k characters, which actually
translates into 4k for English with Unicode Compression on (less a bit for
the record overhead.) So, if you have 17 Text fields defined at 255
characters each, the table may be too wide to edit.

--
Allen Browne - Microsoft MVP. Perth, Western Australia
Tips for Access users - http://allenbrowne.com/tips.html
Reply to group, rather than allenbrowne at mvps dot org.

"Wayne" <cqdi...@volcanomail.com> wrote in message
news:884ce604-abcb-4ef1...@v15g2000prn.googlegroups.com...

[Wayne]

On Aug 15, 4:32 pm, "Allen Browne" <AllenBro...@SeeSig.invalid> wrote:
> It's the actual number of characters in the field that determines how much
> disk space is used.
>
> Internally, Access uses pointers to manage the saved data, so a Text field
> defined at 255 characters does not use up 255 bytes (double for Unicode) on
> the drive, unless you actually type 255 characters into it.
>
> Where it does make a difference is the buffer Access uses to hold and edit
> the current record(s.) That's limited to 2k characters, which actually
> translates into 4k for English with Unicode Compression on (less a bit for
> the record overhead.) So, if you have 17 Text fields defined at 255
> characters each, the table may be too wide to edit.
>
> --
> Allen Browne - Microsoft MVP.  Perth, Western Australia

> Tips for Access users -http://allenbrowne.com/tips.html

> Reply to group, rather than allenbrowne at mvps dot org.
>

Thanks for the informative answer Allen. Would I be correct in
assuming that memo fields don't contribute to the total buffer size
and are handled in a different manner?

[Allen Browne]

Each BLOB field (Memo, OLE Object, ...) counts only 10 bytes (the size of
the pointer), regardless of whether it contains 1 character or 64k.

--
Allen Browne - Microsoft MVP. Perth, Western Australia

Tips for Access users - http://allenbrowne.com/tips.html

Reply to group, rather than allenbrowne at mvps dot org.

"Wayne" <cqdi...@volcanomail.com> wrote in message

news:af8c76f7-dffd-46aa...@u20g2000prg.googlegroups.com...

> On Aug 15, 4:32 pm, "Allen Browne" <AllenBro...@SeeSig.invalid> wrote:
>> It's the actual number of characters in the field that determines how
>> much
>> disk space is used.
>>
>> Internally, Access uses pointers to manage the saved data, so a Text
>> field
>> defined at 255 characters does not use up 255 bytes (double for Unicode)
>> on
>> the drive, unless you actually type 255 characters into it.
>>
>> Where it does make a difference is the buffer Access uses to hold and
>> edit
>> the current record(s.) That's limited to 2k characters, which actually
>> translates into 4k for English with Unicode Compression on (less a bit
>> for
>> the record overhead.) So, if you have 17 Text fields defined at 255
>> characters each, the table may be too wide to edit.
>>