Hi René, everybody!
René Fournier wrote:
[[...]] However, even if the Index can't fit in memory (4GB of RAM, lots
free), just reading it from disk should allow sub-millisecond response, no?
No chance!
Of course, performance of disk drives varies, but AFAIK typical values
are in the range of
Even weirder, I came back to my laptop a couple hours later. And now the same
queries are taking 3-10 seconds instead of 0.01 seconds. What could be causing
this?
On 2009-12-28, at 1:19 PM, René Fournier wrote:
Hmm, weird. I just re-imported the data (after drop/create table, etc.), and
now
To: René Fournier
Cc: mysql
Subject: Re: Why does this query take so long?
Even weirder, I came back to my laptop a couple hours later. And now the same
queries are taking 3-10 seconds instead of 0.01 seconds. What could be causing
this?
On 2009-12-28, at 1:19 PM, René Fournier wrote:
Hmm
:16 AM
To: René Fournier
Cc: mysql
Subject: Re: Why does this query take so long?
Even weirder, I came back to my laptop a couple hours later. And now the same
queries are taking 3-10 seconds instead of 0.01 seconds. What could be
causing this?
On 2009-12-28, at 1:19 PM, René Fournier
So... there is an index, and it's supposedly used:
mysql EXPLAIN SELECT id, province, latitude, longitude, AsText(coordinates),
s_ts_r_m, quartersection FROM qs WHERE
MBRContains(GeomFromText('POLYGON((51.62582589 -114.82248918,51.65126254
-114.82248918,51.65126254 -114.78150333,51.62582589
So just to clarify (hello?), the index which *should* be used (EXPLAIN says so)
and *should* make the query run faster than 4 seconds either isn't used (why?)
or simply doesn't speed up the query (again, why?).
Hmm, weird. I just re-imported the data (after drop/create table, etc.), and
now the spatial queries run fast.
Has anyone seen this sort of thing happen? Maybe the Index got corrupted
somehow, and then MySQL had to do a full table scan (even though EXPLAIN
indicated it would use the Spatial
I've noticed that when developing queries involving complex joins on
tables I sometimes seem to get appallingly long times the first time I run
a query, but the second and subsequent time I run it - even substituting
a different value for a field value I'm matching on - the query runs
- Original Message -
From: [EMAIL PROTECTED]
To: "mySQL list" [EMAIL PROTECTED]
Sent: Tuesday, January 16, 2001 3:57 PM
Subject: Why does 1st query take so long?
I've noticed that when developing queries involving complex joins on
tables I sometimes seem to get appall
On Tue, 16 Jan 2001, Jeremy D. Zawodny wrote:
On Tue, Jan 16, 2001 at 08:21:19PM +, John Stumbles wrote:
I can't readily reproduce the first-time big difference
scenario.
OK, I can now: I have a table -
MAC_connections:Data records:6689
what does a 'show processlist' reveal?
On 17 Jan 2001 00:08:23 +, John Stumbles wrote:
On Tue, 16 Jan 2001, Jeremy D. Zawodny wrote:
On Tue, Jan 16, 2001 at 08:21:19PM +, John Stumbles wrote:
I can't readily reproduce the first-time big difference
scenario.
OK, I can
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