The following information on free place administration tables applies both to online realm extensions and realm extensions performed offline with the utility routine BREORG.
During realm extension, free place administration tables known as FPA extents can be created in addition to the basic free place administration table (FPA base).
Each FPA extent has a size of 128KB. In 2KB-databases it consists of 64 pages, in 4KB-databases of 32 pages and in 8KB-databases of 16 pages. You can output information on the FPA base and the FPA extents with the utility routine BPRECORD.
The fact that there are FPA extents available in a realm does not, however, indicate anything about the current online extensibility. The FPA extents can be created by running BREORG, without the realm ever having been extendible online. It is also possible that the realm had been extendible online in the past but that this attribute has been revoked since then.
You can remove FPA extents with the utility routine BPGSIZE. For each file, BPGSIZE combines FPA base with any FPA extents which may be available to a new FPA base, without changing the page size (see the manual "Creation and Restructuring", BPGSIZE).