MySQL not using index on DATE when used with '<' or '>' operators?

Posted by Haroldo on Stack Overflow See other posts from Stack Overflow or by Haroldo
Published on 2010-06-18T10:53:22Z Indexed on 2010/06/18 11:43 UTC
Read the original article Hit count: 203

Filed under:

mysql

I'm using explain to test these queries. The col type is DATE

this uses index:

explain SELECT events.* FROM events WHERE events.date = '2010-06-11'

this doesnt

explain SELECT events.* FROM events WHERE events.date >= '2010-06-11'

index as follows (phpmyadmin)

Action  Keyname Type    Unique  Packed  Field   Cardinality Collation   Null    Comment
Edit    Drop    PRIMARY BTREE   Yes No  event_id    18  A       
Edit    Drop    date    BTREE   No  No  date    0   A

i notice cardinality is 0, though there are some rows with the same date..

Related posts about mysql

How to remove MySQL completely with config and library files on ubuntu 12.04 gnome 3.0

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
I tried everything till now: sudo apt-get remove mysql-server mysql-client mysql-common sudo apt-get purge mysql-server mysql-client mysql-common sudo apt-get autoremove and even more commands... But whenever I am trying to locate mysql. I get a no. of files related to mysql command: shell>>… >>> More
mysql: Cannot load from mysql.proc. The table is probably corrupted

as seen on Server Fault - Search for 'Server Fault'
Mysql was started: /usr/bin/mysqld_safe --datadir=/srv/mysql/myDB --log-error=/srv/mysql/logs/mysqld-myDB.log --pid-file=/srv/mysql/pids/mysqld-myDB.pid --user=mysql --socket=/srv/mysql/sockets/mysql-myDB.sock --port=3700 but when I'm trying to do something: ERROR 1548 (HY000) at line 1: Cannot… >>> More
Why is there a /etc/init.d/mysql file on this Slackware machine? How could it have gotten there?

as seen on Server Fault - Search for 'Server Fault'
A client of my IT-consulting service owns a web-development shop. He's been having problems with a Slackware 12.0 server running MySQL 5.0.67. The machine was set up by the client's sysadmin, who left on bad terms. My client no longer employs a sysadmin. As far as I can tell, the only copy of MySQL… >>> More
mysql: Bind on unix socket: Permission denied

as seen on Server Fault - Search for 'Server Fault'
Can't start mysql with: sudo /usr/bin/mysqld_safe --datadir=/srv/mysql/myDB --log-error=/srv/mysql/logs/mysqld-myDB.log --pid-file=/srv/mysql/pids/mysqld-myDB.pid --user=mysql --socket=/srv/mysql/sockets/mysql-myDB.sock --port=3700 120222 13:40:48 mysqld_safe Starting mysqld daemon with databases… >>> More
MySQL – Learning MySQL Online in 6 Hours – MySQL Fundamentals in 320 Minutes

as seen on SQL Authority - Search for 'SQL Authority'
MySQL is one of the most popular database language and I have been recently working with it a lot. Data have no barrier and every database have their own place. I have been working with MySQL for quite a while and just like SQL Server, I often find lots of people asking me if I have a tutorial which… >>> More

Developer IT

MySQL not using index on DATE when used with '<' or '>' operators? - Developer IT

MySQL not using index on DATE when used with '<' or '>' operators?

mysql

Related posts about mysql

How to remove MySQL completely with config and library files on ubuntu 12.04 gnome 3.0

mysql: Cannot load from mysql.proc. The table is probably corrupted

Why is there a /etc/init.d/mysql file on this Slackware machine? How could it have gotten there?

mysql: Bind on unix socket: Permission denied

MySQL – Learning MySQL Online in 6 Hours – MySQL Fundamentals in 320 Minutes

Categories cloud