Re: Acclerating INSERT/UPDATE using UPS

Christopher Browne wrote:
> kawasima@cs.tsukuba.ac.jp (Hideyuki Kawashima) wrote:
>> Joshua,
>>
>> I appreciate your quick & informative reply. And, I also really
>> appreciate your kind comments. Since I have joined this ML 3 hours
>> ago, I tried to be polite and slightly nervous. But I was relieved
>> by your message.
> 
> Your idea sounds interesting; there is likely to be a considerable
> resistance to mechanisms, however, that would be likely to make
> PostgreSQL less robust.
> 
> Be aware, also, that in a public forum like this, people are sometimes
> less gentle than Joshua.
> 
> The fundamental trouble with this mechanism is that a power outage can
> instantly turn a database into crud.

I can think of a few places where I don't care about the data if the
power is lost -

* Web-based session data

A lot of web sites have separate session-only databases.
If the database goes down, we have to truncate the tables anyways when
it comes back up.


* Reporting slaves

We have replication slaves setup for internal (staff-only) reporting.
Often a lot of temp and summary tables as well.

If the data is lost, don't care. Its a reporting database.

Re-syncing from another slave is no biggie for total data loss.

Less a concern given the speed increase of the data it creates as well
as data coming in from the master.


* Front-end cache slaves

Same type of situation as the reporting slaves.
Basic front-end cache that replicates data to take load off the master.

The slaves still have to do all the same insert/updates, but this means
they'll spend less time in locks.

They crash, point the apps to the master or another slave while you fix it.



Weslee