Hello, Tsunakawa-San
> Do you know the reason why data copy was done before? And, it may be > odd for me to ask this, but I think I saw someone referred to the past > discussion that eliminating data copy is difficult due to some processing at > commit. I can't find it. I can share 2 sources why to eliminate the data copy is difficult in hackers thread. Tom's remark and the context to copy relation's data. https://www.postgresql.org/message-id/flat/31724.1394163360%40sss.pgh.pa.us#31724.1394163...@sss.pgh.pa.us Amit-San quoted this thread and mentioned that point in another thread. https://www.postgresql.org/message-id/CAA4eK1%2BHDqS%2B1fhs5Jf9o4ZujQT%3DXBZ6sU0kOuEh2hqQAC%2Bt%3Dw%40mail.gmail.com Best, Takamichi Osumi
