On 2017-12-13 16:02:45 +0900, Masahiko Sawada wrote: > When we add extra blocks on a relation do we access to the disk? I > guess we just call lseek and write and don't access to the disk. If so > the performance degradation regression might not be much.
Usually changes in the file size require the filesystem to perform metadata operations, which in turn requires journaling on most FSs. Which'll often result in synchronous disk writes. Greetings, Andres Freund
