Windows CE 20MB file limit and SQL Server CE

[Matt]

Hello,

I have a Pocket PC application that currently uses an XML file as its
data source.
The file is stored in the memory of the Pocket PC itself and not on a
card.

I have discovered that this XML file cannot exceed 20MB due to a limit
placed by the Windows CE operating system.

My question is, if I used SQL Server CE as the data source would that
solve the 20MB limit problem?
I'm guessing it might create many small files for the data rather than
one large one.

Another question is, if I placed the data source file on a memory card
would it accept files larger than 20MB or still be rejected by Windows
CE (I don't have one to test for my self you see).
This would be slow to access so might not be a solution anyhow.

Thanks in advance.

Matt

 

[Marauderz]

Since I have movies that are a couple of hundred MB in the memory card I'll
have to say yes a file can be bigger than 20MB

 

[Ginny Caughey [MVP]]

Matt,

Have you considered using a delimited text files instead of XML. It must
take forever to parse an XML file that size! You can get a TextDataAdapter
at www.opennetcf.org.

Ginny Caughey
..Net Compact Framework MVP

 

[Chris Tacke, eMVP]

Where did you learn of this "limit"? I know of no such limitations. Maybe
you're confused with the Pocket Access limits?

--
Chris Tacke
Co-founder
OpenNETCF.org
Has OpenNETCF helped you? Consider donating to support us!
http://www.opennetcf.org/donate

 

[Matt]

Hi Ginny,

You're right it does take forever
Hence my other post about using SQL CE which you have seen and replied
to (thanks).

The use of the XML file is existing functionality which I have now
taken over.
I wouldn't like to split it up in to multiple delimited text files
simply because of the sheer number I would have to deal with.
The XML file is in fact a serialised dataset that is copied to the
Pocket PC via the Active Sync link.
This dataset contains the results of many queries from many different
database tables.
When the Pocket PC app is loaded it reads in the XML file and then
deserialises it back into a dataset which is used throughout the
application.

You'll appreciate that it is all very simple and effective with little
code which is why it was done like that but does have the problem
of using lots of memory and being slow to intially load.

Matt

 

[Matt]

Hi Chris,

I discovered that when trying to Active Sync the XML file onto the
Pocket PC it would fail when the file size hit 20MB.
It was OK for anything under that size.
I search around on the news groups and found a posting that there was
limit placed by the operating system.
Of course I am unable to find this posting now that I need to refer to
it.

Maybe I have got hold of the wrong end of the stick and the 20MB limit
is something more specific to my device, like not enough memory?
I'm still learning you see.

Thanks,

Matt

 

[Peter Foot [MVP]]

The maximum file size in main memory (object store) is 32mb, there should
not be such a limit on external storage such as CF or SD cards (which you
should consider for a file of this size).

Peter

 

[Ginny Caughey [MVP]]

Matt,

You're right that the XML does retain the multiple table data in just one
file. Still, I think I'd be tempted to do some testing for performance and
size.

Ginny

 

[Matt]

Peter,

My Pocket PC definately throws a wobbler when using Active Sync for
files greater than 20MB.
Perhaps it is an Active Sync quirk, perhaps it is the version of CE
it's running?
I'll have to test it out tomorrow.
Unfortuanately my company probably won't buy a card just for me to test
with.

Thanks,

Matt

 

[Saverio Tedeschi]

Hi Matt,
have you considere zipping file, then syncing, and finally unzipping it on
your device? I've a commercial component to do that, both on Pc and Pda
size. HTH

 

[Saverio Tedeschi]

Hi,
a little clarification: when I say "I have", actually I mean "I use", and
NOT "I've developed", a component to zip/unzip files. Have a nice day!

 

[Matt]

Hi Peter,

You're right it is 32 MB that I have a problem with.
I'm not sure why I said 20MB, I obviously left it too long between
discovering the problem and posting about it.

Thanks.