Hi
I tried to create an index on one of my tables.
After creating this index, the queries return an empty set, instead of the
expected result.
I have a table user looks like this:
id - int(11)
username - varchar(250)
address - varchar(250)
more columns...
After creating an index:
CREATE INDEX
Hi,
After rebuild the following table, the Cardinality does not get updated.
This table have 18 million of rows. Why this happening and how do I fix it?
Should I run OPTIMIZE TABLE or CHECK TABLE?
mysql show index from UserDetail;
:[EMAIL PROTECTED]]
Sent: Thursday, March 21, 2002 11:11 AM
To: Salada, Duncan
Cc: '[EMAIL PROTECTED]'
Subject: Re: help with index/query
what about
select Url from table where Ref = 'foo'
Salada, Duncan wrote:
I am hoping I can get some help with a difficulty I am
having
I am hoping I can get some help with a difficulty I am having with a table
of mine. I am going to give a lot of background info, so please bear with
me. First, let me say that I using 3.23.49. Now some info about the table.
It currently has 5687391 rows. There are 3 columns in the table: ID
what about
select Url from table where Ref = 'foo'
Salada, Duncan wrote:
I am hoping I can get some help with a difficulty I am having with a table
of mine. I am going to give a lot of background info, so please bear with
me. First, let me say that I using 3.23.49. Now some info about the
: Re: FW: pls help for index problem
Well, how many records are in the table? How many would be returned by the
query you present?
Is the SQL you show the FULL sql?
What is the output of the EXPLAIN SELECT
What about SHOW INDEX FROM TABLE gw.
b.
kmlau wrote:
-Original Message
PROTECTED]]
Sent: Wednesday, October 24, 2001 9:42 AM
To: 'Bill Adams'
Subject: RE: pls help for index problem
Thanks yr promptly reply !!
It seems no any change(improvement) by running explain again after erase
quotes. I also ran the command 'myisamchk -a gw.MYI' before sending
hi,
I encountered a problem about indexing. I want to add index on timerecord
field in table gw (shown as below) to speed up query relating with time.
However, I use explain command (explain select * from gw where timerecord =
'010902') to analyze the performace. As a result, it seems the
kmlau wrote:
I encountered a problem about indexing. I want to add index on timerecord
field in table gw (shown as below) to speed up query relating with time.
However, I use explain command (explain select * from gw where timerecord =
'010902') to analyze the performace. As a result,
-Original Message-
From: kmlau [mailto:[EMAIL PROTECTED]]
Sent: Wednesday, October 24, 2001 9:42 AM
To: 'Bill Adams'
Subject: RE: pls help for index problem
Thanks yr promptly reply !!
It seems no any change(improvement) by running explain again after erase
quotes. I also ran
Hi,
whats the difference between:
alter table tablename add index (name);
alter table tablename add index (age);
alter table tablename add index (birthdate);
alter table tablename add index (city);
compared to:
alter table tablename add index (name,age,birthdate,city);
What I want is
whats the difference between:
alter table tablename add index (name);
alter table tablename add index (age);
alter table tablename add index (birthdate);
alter table tablename add index (city);
These are four INDIVIDUAL keys.. helpful if you want to search by name,
age, birthday, _OR_ city
whats the difference between:
alter table tablename add index (name);
alter table tablename add index (age);
alter table tablename add index (birthdate);
alter table tablename add index (city);
These are four INDIVIDUAL keys.. helpful if you want to search by name,
age, birthday, _OR_ city
Just make sure you have a key on any field you do a query on. Given that
there isn't a whole lot of correlation between your columns (logically
speaking.. ie, age doesn't really match up with city) I wouldn't worry
about compound keys.. they'll actually just slow you down since you need
to
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