While trying to debug a recent bug report on hash indexes [1], I
noticed that pg_verify_checksums don't work on Windows (or at least in
my environment).
initdb -k ..\..\data
pg_verify_checksums.exe ..\..\Data
pg_verify_checksums: short read of block 0 in file
"..\..\Data/global/1136", got only 15 bytes
I have debugged and found that below code is the culprit.
scan_file(char *fn, int segmentno)
{
..
f = open(fn, 0);
..
int r = read(f, buf, BLCKSZ);
if (r == 0)
break;
if (r != BLCKSZ)
{
fprintf(stderr, _("%s: short read of block %d in file \"%s\", got only
%d bytes\n"),
progname, blockno, fn, r);
exit(1);
}
..
}
We are opening the file in text mode and trying to read the BLCKSZ
bytes, however, if there is any Control-Z char, it is treated as EOF.
This problem has been mentioned in the comments in c.h as follows:
/*
* NOTE: this is also used for opening text files.
* WIN32 treats Control-Z as EOF in files opened in text mode.
* Therefore, we open files in binary mode on Win32 so we can read
* literal control-Z. The other affect is that we see CRLF, but
* that is OK because we can already handle those cleanly.
*/
So, I think we need to open the file in binary mode as in other parts
of the code. The attached patch fixes the problem for me.
Thoughts?
[1] - https://www.postgresql.org/message-id/5d03686d-727c-dbf8-0064-bf8b97ffe850%402ndquadrant.com
--
With Regards,
Amit Kapila.
EnterpriseDB: http://www.enterprisedb.com