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From Chuck Murcko <ch...@telebase.com>
Subject Re: An idea for state saving
Date Thu, 30 May 1996 22:07:00 GMT
Let me play devil's advocate here.

What does Alta Vista do? Besides hold the index in RAM?

What's stopping the query output from being written to, say, 10 pages of
10 results each, all linked with numbers and Next/Prev. Point the user
to the first page and there you go.

State frozen to disk, gets cleaned up by a smart garbage collector.

Limitation: Disk bandwidth.

Optical channel to a fast drive or RAID, mmap, ramdisk are also alternatives.

I know it's not snappy and leading edge, but...

Doug MacEachern liltingly intones:
> 
> >  Robert Thau wrote:
> >  However, when the server starts it is possible to open a
> >  each child gets copy of the database handle.
> >
> >Hmmm... there's a risk here that if multiple child processes tried
> >to do queries simultaneously without some kind of locking machinery
> >to serialize them, things could get confused.  Have you got that built
> >into the mod_perl machinery itself, or do people have to explicitly do
> >something like locking a proxy object in the file system?
> 
This is not multiple simultaneous updates to the database, is it? Just
queries, right?

> Yes I agree there is a risk.  There is nothing built into mod_perl to
> safeguard this yet, but I've pounded hard on the server, and didn't have any
> problems.  This is on my list of things to look at closer, if you or anyone
> else has more insight, that would be great.
> 

chuck
Chuck Murcko	N2K Inc.	Wayne PA	chuck@telebase.com
And now, on a lighter note:
In Tulsa, Oklahoma, it is against the law to open a soda bottle without
the supervision of a licensed engineer.

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