Why does a PGC_INTERNAL GUC need an assign hook? I think the GUC should only be there to expose the value; it shouldn't have calculation logic associated with it.
The Checkpoint Segments and the UsableBytesInSegment had to be changed depending on the value of wal_segment_size set during initdb. I will figure out another way to assign these values without using this assign_hook.
+ wal_segment_size = atoi(str_wal_segment_size);
So, you're comfortable interpreting --wal-segsize=1TB or --wal-segsize=1GB as 1? Implicitly, 1MB?
The option was intended to only accept values in MB as the original config --with-wal-segsize option, unfortunately, the patch does not throw error as in the config option when the units are specified.
Error with config option --with-wal-segsize=1MB
configure: error: Invalid WAL segment size. Allowed values are 1,2,4,8,16,32,64.
Should we imitate this behaviour and just add a check to see if it only contains numbers? or would it be better to allow the use of the units and make appropriate code changes?
