Re: Slow Accessing a memo field on a network

Thank you all for your replies but I think you may be missing what I'm
asking. I understand that the memofield access can be slow especially if
the memofiled is large. However, my memofield is no more than 3K but does
contain around 150 lines. My question is why is it so much slower when the
file is open at another workstation on the network, otherwise, it is very
fast to loop through the memofield.

My question is whether it is normal for the memofield access to be very fast
when accessing it over a network on workstation #1. But, very slow if the
table is open at another workstation on the network? I noticed that it is
definitely a lot faster when I simply copy the memofield to a variable and
then access the lines via the local variable.

So, say I have 3 computers (one is the file server). I open the table and
it is slow to do multiple accesses of the memofield but only if it is open
on another computer. My fear is that all data access may be slowing down
but not enough to detect with the eye and that maybe there is something else
I'm not noticing. I have not used Set Refresh so that is just using the
default and I am opening the table via pessimistic locking but nothing is
not locked on the reads. It's just the multiple accessing via the
memofields when the table is open at another workstation that slows
everything down. Also, I don't think this is happening on all LANs and may
depend on the server and network setup. But, it does appear to be happening
on some so it really has me curious.

Thanks,
Mike


"Alex.K" <nomail@xxxxxxxxxx> wrote in message
news:%23k5ccbt%23HHA.1184@xxxxxxxxxxxxxxxxxxxxxxx
Mike,

You should only read the Memo field once and store it to a string var.
Then do all processing on the string. You can also use _MLINE and MLINE()
on strings.

Another method is to use ALINES() and process as an Array



- Craig

"MikeA" <appell@xxxxxxxxxxxxxxxxxx> wrote in message
news:JA5Ii.7361$A72.1856@xxxxxxxxxxx
Anyone have any ideas about this: here's the situation,

I have a memo field that I use in a table and I read various lines from
the memo field for default settings. This makes it so that I don't
always have to modify the structure of the table. The total length of
the memofield is small (under 3K). However, I have to read the memo
field multiple times to get the default values on any particular line.
For example:

set memowidth to 8192
test1 = mline(mytable.mysettings, 1)
test2 = memline(mytable.mysettings, 2)
test3 = memline(mytable.mysettings, 3)
test4 = memline(mytable.mysettings, 4)

There are about 150 lines at present in the field. Here's the strange
thing. I have a method in a form that reads all the values and sets the
objects on the form accordingly. It seems like it is starting to take a
long time to load the form (around 6-10 seconds). But, this delay is
ONLY PRESENT if the table is open on another computer on the network. If
I open the table on the same computer in a separate program (such as VFP)
or I run another instance of my application, then everything is fast.
The slowness only happens if the table is open on another workstation and
it appears that it is just as slow if the table is open on 2 workstations
or 10 (makes no difference). It drastically speeds up when the table is
open on only one workstation and is fast even if that table is open on
one computer with multiple programs (such as if it is open in my app as
well as open in VFP).

I have noticed this problem on both an XP Pro computer (as the server)
with XP workstations and I have also noticed this problem on a real Win
2000 server with XP workstations. I'm using VFP 6/SP3. The problem only
seems to happen when doing multiple reads from the same memofield many
times. In other words, if I do this instead:

m.lcMain = mytable.mysettings

and I then populate the form using m.lcMain then everything is very fast.
It's as if multiple reads to the same memofield is really slow but only
if the table is open on another workstation. There are no virus checkers
or other programs (that I know of) to slow it down). I can't understand
why this is happening but I'm not sure if it is happening on other server
OS's as well or just these few examples I have provided. I'm running the
exe on the local machine. But, it seems to be some kind of network issue
because the speed drastically slows down (reading the memo field multiple
times) whether the table is open on two workstations or 10. It's then
pretty much the same slow speed when open at 2 computers or more but
lightening fast when open at only one. Anyone have any ideas?

Thanks,
Mike






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