On Wed, Apr 25, 2012 at 9:28 AM, Merlin Moncure wrote:
>> That patch actually has more than one optimization in it, I think, but
>> the basic idea is that if we could figure out a way to set
>> HEAP_XMIN_COMMITTED when loading data into a table created or
>> truncated within the same transaction,
On Tue, Apr 24, 2012 at 8:52 PM, Greg Stark wrote:
> On Tue, Apr 24, 2012 at 9:40 PM, Robert Haas wrote:
>> For three things, index pages
>> have hint-type changes that are not single-bit changes.
>
> ? Just how big are these? Part of the reason hint bit updates are safe
> is because one bit def
On Tue, Apr 24, 2012 at 3:40 PM, Robert Haas wrote:
> On Sat, Apr 21, 2012 at 7:08 PM, Greg Stark wrote:
>> The earlier consensus was to move all the hint bits to a dedicated
>> area and exclude them from the checksum. I think double-write buffers
>> seem to have become more fashionable but a sum
On 4/21/12 2:40 PM, Jeff Davis wrote:
> If we do use WAL for hint bit updates, that has an impact on Hot
> Standby, because HS can't write WAL. So, it would seem that HS could not
> set hint bits.
If we're WAL-logging hint bits, then the standby would be receiving
them, so it doesn't *need* to wri
On Tue, Apr 24, 2012 at 9:40 PM, Robert Haas wrote:
> For three things, index pages
> have hint-type changes that are not single-bit changes.
? Just how big are these? Part of the reason hint bit updates are safe
is because one bit definitely absolutely has to be entirely in one
page. You can't
On Sat, Apr 21, 2012 at 7:08 PM, Greg Stark wrote:
> The earlier consensus was to move all the hint bits to a dedicated
> area and exclude them from the checksum. I think double-write buffers
> seem to have become more fashionable but a summary that doesn't
> describe the former is definitely inco
On Sat, Apr 21, 2012 at 5:40 PM, Jeff Davis wrote:
> * In addition to detecting random garbage, we also need to be able to
> detect zeroing of pages. Right now, a zero page is not considered
> corrupt, so that's a problem. We'll need to WAL table extension
> operations, and we'll need to mitigate
On Sat, Apr 21, 2012 at 10:40 PM, Jeff Davis wrote:
> * In addition to detecting random garbage, we also need to be able to
> detect zeroing of pages. Right now, a zero page is not considered
> corrupt, so that's a problem. We'll need to WAL table extension
> operations, and we'll need to mitigate
A lot of discussion took place regarding corruption detection, and I am
attempting to summarize it in a useful way. Please excuse the lack of
references; I'm hoping to agree on the basic problem space and the
nature of the solutions offered, and then turn it into a wiki where we
can get into the de
