Re: Design proposal: fsync absorb linear slider

Greg Smith <greg@2ndQuadrant.com> writes:
> On 7/26/13 5:59 AM, Hannu Krosing wrote:
>> Well, SSD disks do it in the way proposed by didier (AFAIK), by putting
>> "random"
>> fs pages on one large disk page and having an extra index layer for
>> resolving
>> random-to-sequential ordering.

> If your solution to avoiding random writes now is to do sequential ones 
> into a buffer, you'll pay for it by having more expensive random reads 
> later.

What I'd point out is that that is exactly what WAL does for us, ie
convert a bunch of random writes into sequential writes.  But sooner or
later you have to put the data where it belongs.
        regards, tom lane