Re: crash-safe visibility map, take three
| От | Robert Haas |
|---|---|
| Тема | Re: crash-safe visibility map, take three |
| Дата | |
| Msg-id | AANLkTi=7St=B=MONtpwD7eTQe9o2Vzd2j5Vfs0wnmj0b@mail.gmail.com обсуждение исходный текст |
| Ответ на | Re: crash-safe visibility map, take three (Tom Lane <tgl@sss.pgh.pa.us>) |
| Ответы |
Re: crash-safe visibility map, take three
Re: crash-safe visibility map, take three |
| Список | pgsql-hackers |
On Tue, Nov 30, 2010 at 11:16 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote: > How much is "quite a lot"? Do we have any real reason to think that > this solution is unacceptable performance-wise? Well, let's imagine a 1GB insert-only table. It has 128K pages. If you XLOG setting the bit on each page, you'll need to write 128K WAL records, each containing a 12-byte relfilenode and a 4-byte block offset, for a total of 16 bytes of WAL per page, thus 2MB of WAL. But you did just dirty a gigabyte of data. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company
В списке pgsql-hackers по дате отправления: