The range access method uses an index to read a subset of rows that form one or multiple continuous index value intervals. The intervals are defined by the query's range predicates, which are comparisons using any of =, <=>, IN(), IS NULL, IS NOT NULL, >, <, >=, <=, BETWEEN, !=, <> or LIKE.

Some examples:
SELECT * FROM blog WHERE author_id IN (1, 7, 8, 10) SELECT * FROM orders WHERE value > 1000
You know that the range access method is used when EXPLAIN shows type=range.

Naturally, there has to be an index on the column used by the range predicate. Since indexes are ordered, MySQL will, for each interval, dive down the index using the interval start value and read it's way through the index leaves until it reaches the interval end value:

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MySQL database is a registered product of sun Microsystems. It is platform independent in nature that means a database administrator can install MySQL database on different operating systems like windows, Linux, and others. MySQL database uses tables for storing the data and records. Sometimes these tables get corrupted by the several reasons like virus attach, software malfunction, improper system shutdown, hardware problem, and so on. When you are trying to repair corrupt mysql database by “mysqlicheck” command but unable to fix then you can try lower level of mysqlicheck command.

You can use lower level of mysqlicheck command in following manner:

Stop Server Process: To use lower level command of mysqlicheck, you should have to stop the server process. You can do it by using service MySQL stop query.

Find Data Files: After end of the server process, you will have to find the data …

MySQL is a relational database and uses table to store the data. Table has column and row to store records. An Individual column must be created to store each type of data like employee name, employee code, employee address, age, sex, and many more. On the other side row contains the actual value that specified with the column of table.
Example: Lets consider an example, we have created an employee details table. Employee details table has five columns employee name, employee code, employee address, employee age, and employee sex. We can insert values into the employee details table through the insert query.
We have inserted John, s0300, New Jersey, 28, and M. Wherein
John= Employee names0300=Employee codeNew Jersey=Employee adress28=Employee ageM=Employee Sex.
Corruption in Employee Details Table: Corruption in the above table can happen due to severely reasons like operating system failure, power failure, …

I use snmptrapd to catch SNMP traps and then put them into a MySQL database using a pretty generic trap handler. This gives me the opportunity to generate such useful information as: > SELECT HOUR(time) AS "hour", COUNT(*) AS "bounces" FROM snmptraps WHERE hostname = 'XXX' AND time > '2011-07-25' AND trap_oid = 'SNMPv2-MIB::snmpTrapOID.0 IF-MIB::linkDown' […]

GREAT REVIEW! I pretty much agree with all you said in your article, especially at the beggining of your article. Thank you, this info is very useful as always. Keep up the good work! You’ve got +1 more reader of your web blog:) Isabella S.

It seems to be a popular misconception that mk-slave-prefetch is designed to keep a MySQL replica server “warm” and ready to serve production traffic in case the master is demoted or fails. This is not what mk-slave-prefetch does. It’s related, and easy to confuse, but its purpose is different.

The mk-slave-prefetch tool is designed to try to execute a read-only approximation of the write workload that the replica is about to have to perform. It is meant to do this just a little bit before the replication thread (which can only be true if replication is lagging), so that when the replica replays writes to execute replication, it doesn’t have to wait for disk I/O.

Keeping caches warmed up for production traffic requires that the read workload, which does not flow through relay logs, is executed on the server. If you point mk-slave-prefetch at a server, you’re just double-executing the write …

It seems to be a popular misconception that mk-slave-prefetch is designed to keep a MySQL replica server “warm” and ready to serve production traffic in case the master is demoted or fails. This is not what mk-slave-prefetch does. It’s related, and easy to confuse, but its purpose is different. The mk-slave-prefetch tool is designed to try to execute a read-only approximation of the write workload that the replica is about to have to perform.

I just uploaded my slides from my Open DB Camp / Froscon talk to Slideshare:

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As i have already discussed in my previous post zfs filesystem and MySQL about zfs overview and two most important command zpool and zfs. I am going to continue with usage of zfs snapshots. It includes create a pool, Create file system, Taking a snapshot, Renaming Snapshots, Listing all snapshots, restoring from snapshot and Moving the snapshot to other location.
A snapshot is a read-only copy of a file system or volume. Snapshots can be created almost instantly, and initially consume no additional disk space within the pool. However, as data within the active dataset changes, the snapshot consumes disk space by continuing to reference the old data and …

Win a free ticket to Percona Live London on October 24-25!  Watch @percona on Twitter, and retweet our TGIF contest tweet to enter. We’ll pick a random retweet and give away a free ticket each week.  If you don’t win this time, try again, or register and get the
early-bird discount (but don’t wait too long: it expires September 18th).

Percona Live London is the can’t-miss event for MySQL in Europe this autumn.  We will have top MySQL speakers from around the world, including Peter Zaitsev and Yoshinori Matsunobu.  The full agenda will be posted soon, but you can see the …