Hi Robert, Thanks for the review.
I've gone through all your review comments and understood all of them except this one: You really cannot > modify the buffer like this and then decide, oops, never mind, I think > I won't mark it dirty or write WAL for the changes. If you do that, > the buffer is still in memory, but it's now been modified. A > subsequent operation that modifies it will start with the altered > state you created here, quite possibly leading to WAL that cannot be > correctly replayed on the standby. In other words, you've got to > decide for certain whether you want to proceed with the operation > *before* you enter the critical section. > Could you please explain this point once more in detail? I am not quite able to understand under what circumstances a buffer would be modified, but won't be marked as dirty or a WAL won't be written for it. -- With Regards, Ashutosh Sharma EnterpriseDB:http://www.enterprisedb.com
