Hello We know that PostgreSQL doesn't support a single relation size over 32TB, limited by the MaxBlockNumber. But if we just 'insert into' one relation over 32TB, it will get an error message 'unexpected data beyond EOF in block 0 of relation' in ReadBuffer_common. The '0 block' is from mdnblocks function where the segment number is over 256 and make segno * RELSEG_SIZE over uint32's max value. So is it necessary to make the error message more readable like 'The relation size is over max value ...' and elog in mdnblocks?
This scene we met is as below, 'shl $0x18, %eax' make $ebx from 256 to 0, which makes segno from 256 to 0. 0x0000000000c2cc51 <+289>: callq 0xc657f0 <PathNameOpenFilePerm> 0x0000000000c2cc56 <+294>: mov -0x8(%r15),%rdi 0x0000000000c2cc5a <+298>: mov %r15,%rsi 0x0000000000c2cc5d <+301>: mov %eax,%r14d 0x0000000000c2cc60 <+304>: mov 0x10(%rdi),%rax 0x0000000000c2cc64 <+308>: callq *0x8(%rax) 0x0000000000c2cc67 <+311>: test %r14d,%r14d 0x0000000000c2cc6a <+314>: jns 0xc2cd68 <mdnblocks+568> => 0x0000000000c2cc70 <+320>: add $0x28,%rsp 0x0000000000c2cc74 <+324>: mov %ebx,%eax 0x0000000000c2cc76 <+326>: shl $0x18,%eax 0x0000000000c2cc79 <+329>: pop %rbx 0x0000000000c2cc7a <+330>: pop %r12 0x0000000000c2cc7c <+332>: pop %r13 0x0000000000c2cc7e <+334>: pop %r14 0x0000000000c2cc80 <+336>: pop %r15 0x0000000000c2cc82 <+338>: pop %rbp 0x0000000000c2cc83 <+339>: retq