what version of DF are you using ?

What is the column type and size defined on the database backend ? BLOB ? how big is the column on database ?

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As Focus said, 32bit apps can only address 2Gb of memory, so this would be your app hard limit, (for the entire APP) not just for this column. So in practical terms, the physical/hard limit would be something lower than 2GB. otherwise you will face the Out-of-Memory error.

but, that's why I asked you what is the real column size at the database. It worth nothing you set a buffer of 100MB in your app. if your Db column is set to hold just 30MB.
You would be just wasting memory.


So you need to set the value, taking that in mind. After you find your optimal value, you later have to deal with reading and writing to the column successfully.
If your are using newer DF release, (18.2 I guess,, not sure ) you have option to work with uchar arrays, do read and write to the column. This will help you a lot, as you dont need to change the String Argument_Size (which is 64k only by default).

If you are in lower version and dont have uchar arrays support to read/writh to table buffers , you have to change argument_size in order to hold the entire column data in a single string variable. Otherwise your data will be truncated, hence corrupted.

At the end, if you find out you have memory constraints.. (due allocating multiple buffers in a big size, as described in that article Focus shared) , you can use Embedded-SQL to fetch data in chunks.. DataFlex 2021 Help (dataaccess.com)

Regards