Re: drop/truncate table sucks for large values of shared buffers

Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> writes:
> On Sat, Jun 27, 2015 at 7:40 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>> I don't like this too much because it will fail badly if the caller
>> is wrong about the maximum possible page number for the table, which
>> seems not exactly far-fetched. (For instance, remember those kernel bugs
>> we've seen that cause lseek to lie about the EOF position?)

> Considering we already have exclusive lock while doing this operation
> and nobody else can perform write on this file, won't closing and
> opening it again would avoid such problems.

On what grounds do you base that touching faith? Quite aside from
outright bugs, having lock on a table has nothing to do with whether
low-level processes such as the checkpointer can touch it.

regards, tom lane