So where's the advantage of VARCHAR ?
Less space on disc = less data retrieved from disc = faster data
retrieval - sometimes. If you have small columns, a small number of
rows, or both, then char columns may be faster. If you have large
columns of varying actual length, lots of rows, or both,
On Wed, Jan 7, 2009 at 2:26 PM, Richard Heyes rich...@php.net wrote:
I still think a CHAR field would be faster than a VARCHAR because of
the fixed row length (assuming every thing else is fixed). Perhaps
someone from the MySQL list could clarify...?
Say that your column length goes up to
There are other factors. If a table is completely fixed in size it makes
for a faster lookup time since the offset is easier to compute. This is
true, at least, for myisam tables. All books on tuning that I have read
have said the CHAR makes for more efficient lookup and comparison that
On 1/7/09, Jim Lyons jlyons4...@gmail.com wrote:
There are other factors. If a table is completely fixed in size it makes
for a faster lookup time since the offset is easier to compute. This is
true, at least, for myisam tables. All books on tuning that I have read
have said the CHAR makes
On Tue, Jan 6, 2009 at 3:13 PM, Jerry Schwartz
jschwa...@the-infoshop.com wrote:
Each account has multiple customers, and each customer has multiple sales. I
want to get the top 20 customers for each account.
On Wed, Jan 7, 2009 at 9:17 AM, David Giragosian dgiragos...@gmail.com wrote:
On 1/7/09, Jim Lyons jlyons4...@gmail.com wrote:
There are other factors. If a table is completely fixed in size it makes
for a faster lookup time since the offset is easier to compute. This is
true, at least, for
Hi Jed,
If you are using LVM, you might consider snapshotting, however, doing a live
snapshot without stopping mysql server would only work if you were copying
only myisam tables. Mysql-hot-copy would probably be better, but either way,
you need to flush your tables, which will briefly lock
Claudio,
ehmthe problems is exactly that. On production server you cannot stop or
lock the server so I need
the replication slave mainly for backups (actually MySQL replication is
simply great for this)
Just don't rely on the slave to BE the backup. You can use it to make
it easier to
A question on grouping I've never been able to solve...
create table j (proj char(3), id int, score double,cpid char(32),team
char(10));
insert into j values('aaa',1,100,'a','team1');
insert into j values('bbb',2,200,'a','team1');
insert into j
Phil
is there any way to modify this query so that it would
return the team having the most entries?
See Within-group aggregates at http://www.artfulsoftware.com/queries.php
PB
-
Phil wrote:
A question on grouping I've never been able to solve...
create table j (proj char(3), id int,
When we run a large query other queries start to back up when the large one
gets to the 'creating sort index' phase, this lock seems to affect the whole
server, all databases... does anyone know what may be causing this?
Thanks in advance
--
David Scott
On Wed, Jan 7, 2009 at 6:20 PM, David Scott
critt...@desktopcreatures.comwrote:
When we run a large query other queries start to back up when the large one
gets to the 'creating sort index' phase, this lock seems to affect the
whole
server, all databases... does anyone know what may be
At 11:20 AM 1/7/2009, you wrote:
When we run a large query other queries start to back up when the large one
gets to the 'creating sort index' phase, this lock seems to affect the whole
server, all databases... does anyone know what may be causing this?
Thanks in advance
--
David Scott
David,
Description:
I'm installing a new instance of MySQL using 5.0.67 (source) and get
the following
from mysql_secure_installation:
Set root password? [Y/n] Y
New password:
Re-enter new password:
Password updated successfully!
Reloading
-Original Message-
From: baron.schwa...@gmail.com [mailto:baron.schwa...@gmail.com] On
Behalf Of Baron Schwartz
Sent: Wednesday, January 07, 2009 9:54 AM
To: Jerry Schwartz
Cc: mysql@lists.mysql.com
Subject: Re: Limit within groups
On Tue, Jan 6, 2009 at 3:13 PM, Jerry Schwartz
1) InnoDb2) 5.0.51 on Linux
3) No, a Select with a bunch of Joins, a Where, group and order
4) 37 seconds
5) Yes
6) Show Processlist does not show anything, just the user, what are you
looking for?
2009/1/7 mos mo...@fastmail.fm
At 11:20 AM 1/7/2009, you wrote:
When we run a large query other
Oh and we increased the key_buffer_size=1200M (30% of ram) no change.
2009/1/7 David Scott critt...@desktopcreatures.com
1) InnoDb2) 5.0.51 on Linux
3) No, a Select with a bunch of Joins, a Where, group and order
4) 37 seconds
5) Yes
6) Show Processlist does not show anything, just the
At 01:07 PM 1/7/2009, David Scott wrote:
1) InnoDb
2) 5.0.51 on Linux
3) No, a Select with a bunch of Joins, a Where, group and order
4) 37 seconds
5) Yes
6) Show Processlist does not show anything, just the user, what are you
looking for?
David,
I was looking to see if the other queries
On Wed, Jan 7, 2009 at 1:48 PM, Jerry Schwartz
jschwa...@the-infoshop.com wrote:
-Original Message-
From: baron.schwa...@gmail.com [mailto:baron.schwa...@gmail.com] On
Behalf Of Baron Schwartz
Sent: Wednesday, January 07, 2009 9:54 AM
To: Jerry Schwartz
Cc: mysql@lists.mysql.com
Subject:
Hello,
I think following query would help you
For Ascending
select cpid,sum(score),team from j group by cpid order by sum(score)
For Descending
select cpid,sum(score),team from j group by cpid order by sum(score) desc
Thanks!
2009/1/7 Phil freedc@gmail.com
A question on grouping I've
20 matches
Mail list logo
