From: "Tore Bostrup" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Wednesday, February 26, 2003 11:39 AM
Subject: Re: index questions
4: The index name allows you to for instance delete an index, specify it in
a hint, etc. But for the most part, a developer won't ca
[EMAIL PROTECTED]>; <[EMAIL PROTECTED]>
Sent: Wednesday, February 26, 2003 10:29 AM
Subject: Re: index questions
> > 4: The name of an index does not determine whether it gets used or not.
>
> So if I have a primary index on CustID, it will be used if I reference
> "CustID&
Tore,
Thanks very much for taking the time to respond! I'm not insulted by
"basic". Some things I knew, but my questions were basic.
> 1: There is no difference: KEY is a synonym for INDEX.
So these two statements are equivalent:
KEY [index_name] (index_col_name,...)
INDEX [index_name] (index_
port/ta001.html.
I have been unable to verify whether the CHECK constraint is actually
implemented with any table types or in any versions of MySQL.
HTH,
Tore.
- Original Message -
From: "Sheryl Canter" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Tuesday,
please someone answer!
see below
- Original Message -
From: "Sheryl Canter" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Tuesday, February 25, 2003 7:07 PM
Subject: index questions
I have some basic questions that are driving me nuts, and I can't find
I have some basic questions that are driving me nuts, and I can't find
answers anywhere. I've been banging my head against the wall for hours and
hours. I've searched everywhere on the internet and looked in every book I
own. I can't find the information. Here are my questions.
In the CREATE TABLE
* Andy Cheng
> I am trying to learn about indexing and have a few questions.
>
> 1. Does index only apply to query that use = operator in the where clause?
No.
> 2. Does operators such as >, like and between will result to full table
> scan?
No. LIKE "%whatever%" will not use the index, but LIK
Hi,
I am trying to learn about indexing and have a few questions.
1. Does index only apply to query that use = operator in the where clause?
2. Does operators such as >, like and between will result to full table
scan?
3. For example, In the following table:
tbl_A
id int primary key
Hi!
> "Sergei" == Sergei Golubchik <[EMAIL PROTECTED]> writes:
Sergei> Ok, mysqlimport uses LOAD DATA INFILE.
>> > Yes, but they are simply convenient shortcuts to
>> > myisamchk --keys-used=0 -rq
>> > You can enable/disable keys from command line in 3.23.
>>
>> Ok, what is the suggest
MySQL - spam bypasser
> myisamchk --keys-used=3D0 -rq
> You can enable/disable keys from command line in 3.23.
While that would disable the key before the load,
how do I re-enable them afterwards?
-
Before posting, please
Hi!
First: please reply to mysql-list and not directly to me.
Then:
On Dec 04, Barry Roomberg wrote:
> > Hi!
> Hi back.
>
> > Why do you need RAID ? Are you using ext2fs ?
> > With 2.4.2 you can use reiserfs, which does not have 2GB file limit.
>
> Using ext2fs right now. Heard a lot of reise
Thanks, but I'm looking at having this for all objects
drop table mytable retain metadata;
etc
Dave
On Tue, Dec 04, 2001 at 06:52:17PM +0100, Sergei Golubchik wrote:
> Hi!
>
> On Dec 04, David Turner wrote:
> > I've always thought it would be great if there was a way to drop an object but
> >
Hi!
On Dec 04, David Turner wrote:
> I've always thought it would be great if there was a way to drop an object but
> keep the meta data so I can recreate objects without having to store the ddl
> somewhere.
>
> alter table drop index retain metadata
>
> Would be helpful.
That's what ALTER T
I've always thought it would be great if there was a way to drop an object but
keep the meta data so I can recreate objects without having to store the ddl
somewhere.
alter table drop index retain metadata
Would be helpful.
Dave
On Tue, Dec 04, 2001 at 11:19:43AM -0500, Robert Alexander wrote
Hi Barry,
It is, indeed, faster to load the data then create the indexes.
Instead of 'disable' and 'enable', you could try:
- ALTER TABLE DROP index (or drop the table and create it without indexes.)
- load your data
- ALTER TABLE ADD index
HTH,
/Rob
At 09:40 -0500 2001/12/04, Barry Roomberg
Hi!
On Dec 04, Barry Roomberg wrote:
> I'm trying to understand the most efficient load sequence
> possible.
>
> I've got 2 large tables. Each is about 50 million rows,
> taking about 20GB of disk space.
>
> My system is a dual PIII 850, running Linux 2.4.2-2smp #1 SMP.
> Memory: 1GB.
>
> The
I'm trying to understand the most efficient load sequence
possible.
I've got 2 large tables. Each is about 50 million rows,
taking about 20GB of disk space. My disk is accessed
via fibre channel, and can read/write about 40 MB per
second.
My system is a dual PIII 850, running Linux 2.4.2-2smp
rick herbel wrote:
> Question - Why is key len,ref null ?? Is it not using my key? Why does it
> say type range
> here and below it says type ref the table has 134000 records in it so it
> should be using key.
Have you run myisamchk -a on the table? (Or ANALYZE TABLE from the sql prompt?)
b.
Questions about index
mysql> show index from listing;
+-++-+--+-+-
--+-+--+
| Table | Non_unique | Key_name| Seq_in_index | Column_name |
Collation | Cardinality | Sub_part |
+-++
On Tue, Nov 13, 2001 at 11:03:00PM -0600, Christian Stromberger wrote:
>
> I understand that an index is used to "speed stuff up", but am foggy
> on the details.
You might find this helpful:
http://www.linux-mag.com/2001-06/mysql_01.html
> Eg, let's say I have an "authors" table with fname, mna
Hi Chris!
> I understand that an index is used to "speed stuff up", but am foggy on the
> details.
Ayup. one of the beauties of MySQL/RDBMS is that -you- don't really need
to know or -do- much except declare the index. :)
> I assume I set up the index like so in the create table:
> ...
> unique
I understand that an index is used to "speed stuff up", but am foggy on the
details. Eg, let's say I have an "authors" table with fname, mname, and
lname fields for first, middle and last names. Plus an auto_increment
primary key. I will want to sort on author last name for output of sorted
aut
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