HELP!!!!! (JOIN, GROUP BY INDEX)

how come no one response to my email? thanks! My question is below: Hi, I have some question on JOIN and INDEX usage on GROUP BY. Hope you can help me. thanks! 1. If there is any performance differenct for join from a small table to a big table and join from a big table to a small table? 2. If

JOIN, GROUP BY INDEX

Hi, I have some question on JOIN and INDEX usage on GROUP BY. Hope you can help me. thanks! 1. If there is any performance differenct for join from a small table to a big table and join from a big table to a small table? 2. If index on group by column order, will it have any query performance

mysql error

Hi, I keep getting the following error in mysql error file. Could anyone tell me what's going on and how to avoid this kind of error? 031117 2:44:37 Error reading packet from server: Lost connection to MySQL server during query (server_errno=2013) 031117 2:44:37 Slave: Failed reading log

Innodb: Can't init databases

Hi, I removed idbdata and iblogs and recreated idbdata and iblogs. But I keeps getting Can't init databases. I still have a lot of disk space. Could any one please tell me what's wrong? Here are message from error log InnoDB: Database physically writes the file full: wait... InnoDB: Progress in

select count(*) / select count(column) in innodb

Hi, select count(*) is very slow in innodb (because it is a table scan). Is there any difference if I change it to select count(column). I did some test and some times select count(*) is really slow and some time select count(column) is slow. Could anyone help me? If I need do a select(*) in

cardinality in SHOW INDEX

Hi, Some time I saw cardinality in SHOW INDEX is null. Why this happening? Then, I did a OPTIMIZE TABLE on the table and the number was getting back. We are going to switch all of our table to innodb. Will innodb has this problem? If it happend, how to fix it in innodb. Using OPTIMIZE TABLE? Is

help on 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;

RE: Dummy problem with UPDATE for DATETIME field

your date format is not correct. It should be activity_date = '2003-9-10 10:00:00'. -Original Message- From: Franck Babin [mailto:[EMAIL PROTECTED] Sent: Monday, October 06, 2003 8:28 AM To: [EMAIL PROTECTED] Subject: Dummy problem with UPDATE for DATETIME field I have this simple sql

replication setting

Hi, I have question on replication setting in my.cnf what is the difference between relay-log and relay-log-index? If I do not set them, what will happen? thanks Hsiu-Hui -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:

case sensitive?

Hi, I have questions on string comparison: Table: user_att +-+--+--+-+-+---+ | Field | Type | Null | Key | Default | Extra | +-+--+--+-+-+---+ | user_id | int(11) | | PRI | 0

Query performance

Hi, I have a table with 18 million of rows. The table structure is describe user_att +-+--+--+-+-+---+ | Field | Type | Null | Key | Default | Extra | +-+--+--+-+-+---+ | user_id | int(11)

explain

Hello, When I do a explain on a query, I got the following: +-+ | Comment | +-+ | Impossible WHERE noticed after reading const tables |

RE: explain

. -Original Message- From: Jeremy Zawodny [mailto:[EMAIL PROTECTED] Sent: Friday, September 19, 2003 3:13 PM To: Hsiu-Hui Tseng Cc: [EMAIL PROTECTED] Subject: Re: explain On Fri, Sep 19, 2003 at 02:12:02PM -0700, Hsiu-Hui Tseng wrote: Hello, When I do a explain on a query, I got

migrate data from myisam to innoDB

Hello, I migrated all my tables to innoDB from MyIsam. After migrated, I ran Show TAble Status. Why the row count is change. In MyIsam table status.rows = 316202 the new InnoDB table status.rows = 287341 When doing select count(*) from TABLE. I go 316202 rows. Why this happening? Is there any

RE: migrate data from myisam to innoDB

, September 18, 2003 10:05 PM To: Hsiu-Hui Tseng; [EMAIL PROTECTED] Subject: Re: migrate data from myisam to innoDB Hsiu-Hui Tseng wrote: Hello, I migrated all my tables to innoDB from MyIsam. After migrated, I ran Show TAble Status. Why the row count is change. In MyIsam table status.rows

innodb question

After specify the variablies for innodb in my.cnf file, I started mysql server. Why I did not see the creating output? But I can see it in err file. thanks Hsiu-Hi -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/[EMAIL