Size Limit for Format IDX-8 Data File

I created a format IDX-8 data file using Visual COBOL 5.0 on Microsoft Visual Studio Community 2019. I would like to know what is the size limit for this data file. I read a knowledge base articled at https://www.microfocus.com/documentation/visual-cobol/vc60/DevHub/HRFLRHFILE09.html . It states that format IDX-8 "Supports Files Logically >4 Gb". What is meant by "logically"? And what is the maximum size that an format IDX-8 data file will support? I performed a rebuild on the file to obtain the file information  which is as follows:

"File : C:\\tpselfax.DAT
Organization : Indexed
Format : IDX-8
Recording Mode : Fixed
Compression : N
Maximum Record Length : 512
Minimum Record Length : 512
Index Node Size : 1024
Number of data records : 1413292
Data Created With Extfh Version : 19999
Last Updated With Extfh Version : 19999

Key Description (where 'Start' is measured from offset 1):
Key Start Length Dupl Key Comp Sparse Char
0 1 33 N
C:\\tpselfax.DAT /i "

Thanks in advance. 

I created a format IDX-8 data file using Visual COBOL 5.0 on Microsoft Visual Studio Community 2019. I would like to know what is the size limit for this data file. I read a knowledge base articled at https://www.microfocus.com/documentation/visual-cobol/vc60/DevHub/HRFLRHFILE09.html . It states that format IDX-8 "Supports Files Logically >4 Gb". What is meant by "logically"? And what is the maximum size that an format IDX-8 data file will support? I performed a rebuild on the file to obtain the file information  which is as follows:

"File : C:\\tpselfax.DAT
Organization : Indexed
Format : IDX-8
Recording Mode : Fixed
Compression : N
Maximum Record Length : 512
Minimum Record Length : 512
Index Node Size : 1024
Number of data records : 1413292
Data Created With Extfh Version : 19999
Last Updated With Extfh Version : 19999

Key Description (where 'Start' is measured from offset 1):
Key Start Length Dupl Key Comp Sparse Char
0 1 33 N
C:\\tpselfax.DAT /i "

Thanks in advance. 

The documentation for indexed file size limitations can be found here.

Thanks for the resource. Prior to migrating to Visual COBOL, our indexed files were of a format 3 created using NetExpress. These format 3 files did not support more than 1GB. In reading the file size limit table on the link you provided, it states that a format 3 can handle 4GB if its “Exclusive(#)” but only 1GB if its “shared with default locking” which informs me that our files are probably “shared with default locking”. If so, then that means that the format 8 files will also not support more than 1GB assuming they are “shared with default locking” given that the table size limit of the link you provided has the same size limit for this format if it is "shared with default locking" . Is that a correct reading of the table for size limit on the link you provided? Thanks in advance.  

Look at the MAXFILESIZE column. If you use IDXFORMAT"8" and set the extfh.cfg option MAXFILESIZE=8 then you can have shared files that are 256tb in size, If you also set the option FILEPOINTERSIZE to 8 then your IDXFORMAT"8" files can be 4eb in size.

Is there documentation on how to configure the extfh.cfg option?