Diskspace for memo fields

Diskspace for memo fields

Post by wayn.. » Thu, 02 Jun 1994 10:44:22



Can someone give me a detail description on diskspace consumed by
MEMO fields in a Foxpro database?  Particularly if the vast majority
of them are not filled in.
 
 
 

Diskspace for memo fields

Post by Justified And Ancien » Wed, 08 Jun 1994 05:44:41




>Can someone give me a detail description on diskspace consumed by
>MEMO fields in a Foxpro database?  Particularly if the vast majority
>of them are not filled in.

And the suprise answer is ... almost none.

Each memo field consumes 10 bytes in your database.  But the .fpt file
is not extended until you actually put something into the memo field.

If you have a memo field that seems to be taking too much space, do
a PACK MEMO on it, and see what that does.  When you alter the contents
of a memo field, FoxPro doesn't check to see if it can re-use another
portion of the .fpt file, it just extends the file and sticks your
new memo field onto the end of it.
--

=My thoughts, my posts, my ideas, my responsibility, my beer, my pizza.  OK???=



 
 
 

Diskspace for memo fields

Post by Stan Varlam » Wed, 08 Jun 1994 20:48:02



...

: If you have a memo field that seems to be taking too much space, do
: a PACK MEMO on it, and see what that does.  When you alter the contents
: of a memo field, FoxPro doesn't check to see if it can re-use another
: portion of the .fpt file, it just extends the file and sticks your
: new memo field onto the end of it.
: --

Do not forget SET BLOCKSIZE (see Help)! May save up to 50%!
--

 
 
 

Diskspace for memo fields

Post by Justified And Ancien » Wed, 08 Jun 1994 23:36:25




>: If you have a memo field that seems to be taking too much space, do
>: a PACK MEMO on it, and see what that does.  When you alter the contents
>: of a memo field, FoxPro doesn't check to see if it can re-use another
>: portion of the .fpt file, it just extends the file and sticks your
>: new memo field onto the end of it.

>Do not forget SET BLOCKSIZE (see Help)! May save up to 50%!

Yea, but make sure you have VERY GOOD DOCUMENTATION if you go about
playing with it.  The memo blocksize is stored in the .dbf header, and
if the header gets crunched, you have to know what blocksize you're
using in order to get it back.

Sure, you can go play around, but...
--

=My thoughts, my posts, my ideas, my responsibility, my beer, my pizza.  OK???=
=This .signature will be on vacation from 06/13/94 through 06/24/94.  Have you=
=given your .signature a vacation lately?                                     =

 
 
 

Diskspace for memo fields

Post by Stan Varlam » Thu, 09 Jun 1994 10:53:09



:...
: >: new memo field onto the end of it.
: >
: >Do not forget SET BLOCKSIZE (see Help)! May save up to 50%!

: Yea, but make sure you have VERY GOOD DOCUMENTATION if you go about
: playing with it.  The memo blocksize is stored in the .dbf header, and
: if the header gets crunched, you have to know what blocksize you're
: using in order to get it back.

: Sure, you can go play around, but...

Do not forget BACKUP copies!

I don't think it is a scientific approach not to do something useful because
if we do it wrong, it'll be screwed up. Just cover up with backups,
what's the problem?
--

 
 
 

Diskspace for memo fields

Post by Justified And Ancien » Thu, 09 Jun 1994 23:29:44




>: >: new memo field onto the end of it.
>: >
>: >Do not forget SET BLOCKSIZE (see Help)! May save up to 50%!

>: Yea, but make sure you have VERY GOOD DOCUMENTATION if you go about
>: playing with it.  The memo blocksize is stored in the .dbf header, and
>: if the header gets crunched, you have to know what blocksize you're
>: using in order to get it back.

>: Sure, you can go play around, but...

>Do not forget BACKUP copies!

>I don't think it is a scientific approach not to do something useful because
>if we do it wrong, it'll be screwed up. Just cover up with backups,
>what's the problem?

I was thinking more of the "what do you mean you spilled coffee on the
server" type of problems.  Anybody who doesn't have good backups before
scheduled compressions is asking for trouble.
--

=My thoughts, my posts, my ideas, my responsibility, my beer, my pizza.  OK???=
=This .signature will be on vacation from 06/13/94 through 06/24/94.  Have you=
=given your .signature a vacation lately?                                     =
 
 
 

Diskspace for memo fields

Post by Yellow Disk U » Sat, 11 Jun 1994 23:15:33





>>Can someone give me a detail description on diskspace consumed by
>>MEMO fields in a Foxpro database?  Particularly if the vast majority
>>of them are not filled in.
>And the suprise answer is ... almost none.
>Each memo field consumes 10 bytes in your database.  But the .fpt file
>is not extended until you actually put something into the memo field.
>If you have a memo field that seems to be taking too much space, do
>a PACK MEMO on it, and see what that does.  When you alter the contents
>of a memo field, FoxPro doesn't check to see if it can re-use another
>portion of the .fpt file, it just extends the file and sticks your
>new memo field onto the end of it.
>--

Has anybody tried to join several char and num fields into one single
memo field (like sort of variable length fields)? I think that indexing
shouldn't be a problem. What character should be used as field separator?

By the way I noticed that the best way to index a memo field is
something like:

   INDEX ON PADR(m.memo,10," ") TAG Memotag

This ensures that although the first memo field is empty the index is
still generated correctly. Any opinions?

_arto


 
 
 

Diskspace for memo fields

Post by Yellow Disk U » Sun, 12 Jun 1994 23:50:19


Quote:>   INDEX ON PADR(m.memo,10," ") TAG Memotag
>This ensures that although the first memo field is empty the index is
>still generated correctly. Any opinions?

Sorry. I should have written INDEX ON ""+PADR(...

_arto

 
 
 

1. What is the syntax for copy a memo to a database memo field

Can someone please tell me what the syntax is for copying the contents
of a memo field (i.e., memo.lines) to a memo field in a database.
Better yet, I know that

Memo.lines.LoadFromFile('filename')

will load the contents of a file into memo.lines.  Is there a way to use
LoadFromFile to load directly into the memo field in the database.

ALL help is appreciated.

Thanks, Ken

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