Dear Horiguchi-san, > I'm not sure. I think that int is generally thought that it is tied > with an integer type of any size. min_apply_delay is tightly bond > with a catalog column of int32 thus I thought that (PG_)INT32_MAX is > the right limit. So, as I expressed before, if we assume sizeof(int) > <= sizeof(int32), I' fine with using INT_MAX there.
I have checked some articles and I think platforms supported by postgres regard Int as 32-bit integer. According to the definition of C99, actual value of INT_MAX/INT_MIN depend on the implementation - INT_MAX must bigger than or equal to 2^15 - 1 [1]. So theoretically there is a possibility that int is bigger than int, as you worried. Next, I checked some data models, and found ILP64 that regards int as 64-bit integer. In this case INT_MAX may be 2^63-1, it exceeds PG_INT32_MAX. I cannot find the proper document about the type, but I can site a table from the doc[2]. ``` Datatype LP64 ILP64 LLP64 ILP32 LP32 char 8 8 8 8 8 short 16 16 16 16 16 _int32 32 int 32 64 32 32 16 long 64 64 32 32 32 long long 64 pointer 64 64 64 32 32 ``` I'm not sure whether the system survives or not. According to [2], a few system released, but I have never heard. Modern systems have LP64 or LLP64. > There have been a few examples of ILP64 systems that have shipped > (Cray and ETA come to mind). In another paper[3], Sun UltraSPARC, which is 32-bit OS and use SPARC64 processor, seems to use ILP64 model, but it may be ancient OS. > 1995 Sun UltraSPARC: 64/32-bit hardware, 32-bit-only operating system. HAL > Computer’s SPARC64: uses ILP64 model for C. Also, I checked buildfarm animals that have Sparc64 architecture, but their alignment of int seems to be 4 byte [4]. > checking alignment of int... 4 Therefore, I think we can say that modern platforms that are supported by PostgreSQL define int as 32-bit. It satisfies the condition sizeof(int) <= sizeof(int32), so we can keep to use INT_MAX. [1] https://www.dii.uchile.cl/~daespino/files/Iso_C_1999_definition.pdf [2] https://unix.org/version2/whatsnew/lp64_wp.html [3] https://queue.acm.org/detail.cfm?id=1165766 [4] https://buildfarm.postgresql.org/cgi-bin/show_stage_log.pl?nm=castoroides&dt=2023-01-30%2012%3A00%3A07&stg=configure#:~:text=checking%20alignment%20of%20int...%204 Best Regards, Hayato Kuroda FUJITSU LIMITED
