MyISAM is the non-transactional storage engine for MySQL. It provides high-speed storage and retrieval, as well as fulltext searching capabilities. In addition, it is the default storage engine type for versions of MySQL prior to 5.5.

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How to increase fast backup and restore of 500GB database using mysqldump?

There is a database A size of 500GB. Tables in database A contains both MyISAM and INNODB tables. MyISAM tables are master tables and Innodb tables are main transaction tables. Backup and restore ...
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How much does table size affect performance?

Lets say I have a MyISAM table (amongst other tables) with 2938347 rows. This table is merely being used for logging and doesn't get emptied very often. By not regularly archiving or deleting these ...
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1answer
198 views

Can I partially invalidate the MySQL table cache?

I want to set a fairly large table to MyISAM mode to keep it cached proactively. The table file is approximately 3GB. After several hours, MySQL invalidates the entire table from cache, while < ...
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Not enough space for MySQL optimize; do new rows overwrite existing data?

My MyISAM table consumed most of my disk space. I deleted a significant portion of the table, but the optimize command (to clean out the deleted data) does not have sufficient space. Is there any ...
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Does a MyISAM table locks if I copy it while MySQL is running? (READ DISCLAIMER)

DISCLAIMER: I'm very aware this is not supposed to be done, but time consistency between tables aren't a concert here and Im trying whatever pops in my mind right now to have alternatives for ...
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791 views

Why innodb doesn't store geospatial data?

I am very curious. I have business tables. Now I think I will have to create a separate table, location table. That separate table should be myisam. But why would I do so? Why can't innodb store ...
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552 views

Dynamically changeable database

We have a database and some data is stored in a Trucrypt folder, my question is how can I include this trucrypt folder. The data type is MyISAM. I saw there is a symbolic link, but not really clear ...
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890 views

How to backup a MySQL database without slowing the application?

I'm an application developer and wondering about our database backup strategy. Right now our sysadmins backup our database every 8 hours. I don't really know how the do it, but while the backup is ...
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684 views

Should I move to InnoDB during a planned migration?

I'm shortly migrating a Debian Lenny webserver to another host and Debian Squeeze. The standard MySQL installation even on Squeeze is 5.1 and therefore would default to MyISAM - I'm inclined to stick ...
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4answers
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mysql insert into indexed table taking long time after few million records

I have a table like this CREATE TABLE IF NOT EXISTS `dnddata` ( `numbers` varchar(10) NOT NULL, `opstype` char(1) NOT NULL, PRIMARY KEY (`numbers`) ) ENGINE=MyISAM DEFAULT CHARSET=latin1 ...
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1answer
347 views

Is there any performance difference in using a unique index on primary key?

I know there are lost of similar questions to this one, but none that really answers this: Is there ANY difference in performance in using an unique index in a primary key, using a MyISAM table on a ...
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MySQL 5.5 High CPU Usage

I have been working with a client with high traffic website(500k visitors and 600-800 active users at any given time). This uses wordpress and the DB is using MyISAM engine. The problem we had was ...
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1answer
143 views

What if I want to keep using MyISAM

In my current use of MyISAM the databases are extremely small and kept for a few weeks after which time they are deleted and completely rebuilt with a clean slate. The script uses MYISAM tables and ...
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2answers
343 views

Writing transactions to .MYD file to take Backup

I'm trying to backup MySQL DB by archiving the data directory of required databases. I'm doing FLUSH TABLES WITH READ LOCK before taking the backup, but even then some of the transactions were not ...
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2answers
149 views

How to speed up mysql export and import

I need to perform a DB migration from Server A to Server B. Server A: MySQL version installed 5.0.6 Server B: MySQL version installed 5.6.20 OS: Both are running RedHat Linux 64bit. 16 ...
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1answer
619 views

Tuning key_reads in MySQL

We are trying to tune our MySQL database (Myisam, 5.1.73) which is getting busy. We investigated Key_reads: $ mysqladmin ext -ri10 | grep Key_reads During a normal load we have the following ...
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1answer
284 views

What's the optimal server configuration for fastest inserting in a MySql database in this scenario?

I have a MyISAM table partitioned by range with 90 partitions representing the last 90 days. I expect this table to receive somewhere between 500 million to 1 billion records before i start rotating ...
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1answer
4k views

MySQL high CPU usage (MyISAM table indexes)

I have a problem with an inherited MySQL database. From time to time mysqld uses up to 2300% CPU.. The only solution is to service mysql stop and run an myisamchk -r on a table. After the indexes have ...
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785 views

MySQL Tables Require Daily Repairs - Server, Table or HD?

I've been experiencing a weird issue with one of MySQL DBs. Every day, sometimes 2-3 times per day, I'll need to repair the tables. The MySQL DB has 25 tables with 5.6m rows in total. The bigger ones ...
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1answer
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How to check growth of database in mysql?

I want to know is there any method to check the growth of database on file EXAMPLES Database A contains all tables in INNODB storage engine Database B contains all tables in MyISAM storage engine ...
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1answer
1k views

MySQL ignoring index, index cardinality is the same as number of records in the table (?!)

Everyone, I could use an extra set of eyes on an issue we've come across. Here's what we're seeing: We're writing some code to migrate our messages to a new table called communications. We're ...
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2answers
1k views

Quick MySQL Backup

I have a database which is grown to 3GB and it has 3 MyISAM tables. And I have 4GB RAM. What will be the best (quick) way to backup this database without any performance lack. Or mysqldump will work ...
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1answer
235 views

mysql Wrong bytesec: 0-0-0 at linkstart: 0

I have several MySQL (MyISAM) tables that have been corrupted. Running CHECK TABLE mytable returns: > +-----------------+-------+----------+----------------------------------- | > ...
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1answer
703 views

Fastest way to copy data from MyISAM to InnoDB

I want to copy all data from a MyISAM table with 16 millions rows to a InnoDB table, that will have a different (optimized) schema. See tables below to see the changes. However, every approach I try ...
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1answer
3k views

Setting up replication for MyISAM tables?

Before setting up a replication within MySQL, the data first needs to be transferred to the slave. Since MyISAM tables can be copied as files. Would it be okay to copy MyISAM files, .myd .myi .frm, ...
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Table compression in InnoDB?

I have read that table index compression happens just in MyISAM, but I came across an article in dev.mysql that said: InnoDB supports table and index compression! So now what is the pros of MyISAM? ...
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1answer
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MySQL Bug required remedy : [Warning] Invalid (old?) table or database name '#sql-'

We have a master & multiple slave replication in our production environment. At first, I found this error in the mysql error log on the master and later on the slave. As for all the replication, ...
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1answer
2k views

What could cause waiting for table metadata lock?

I am using a MySQL 5.6 DB with MyISAM tables under FreeBSD 8.3. The main part of code is in PHP, but the problem arises, when I launch the self-written on C++ chat-server. I use the mysql.h for DB ...
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1answer
653 views

Getting Random Sample from large database MYSQL (No Auto Inc Field)

You were so helpful with my last question, I thought id throw another one at you thats stumping me. Basically I got a table, requirements from company was it was all supposed to be 1 table so I got ...
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Are there implicit indexes in InnoDB like MyISAM?

If you have (id, a, b, c, d) table with primary key (id) and another key (a, b, c), in MyISAM that means that you also have the following implicit keys: (a) (a, b) (a, b, c, id) Is this valid for ...
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1answer
309 views

Can I use mysql to serve 100's of millions of small image files?

I need to serve 300,000,000 small image files totaling 1.5TB. Trying to unpack these files to individual files on the file system is next to impossible (1 MByte/sec throughput rates to create the ...
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1answer
255 views

Which MySQL table to use for read-only, bulk-loaded tables?

So I have a workload on 2 key tables in my application with the following characteristics: READ-ONLY DATA The data is bulk-loaded in a fully consistent manner from a single process on a schedule, ...
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Choosing between MyISAM & InnoDB - two servers with related tables

I don't want to make a mistake. I am about to put my website online and I admit I haven't thought about which MySQL engine to choose: MyISAM or InnoDB. I read here and there that InnoDB should be ...
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1answer
2k views

Optimizing MySQL for Read-Only?

We have 14 GB worth of CSV's which total 138 million rows. I imported this into a MySQL table first with InnoDB, and then tried again with MyISAM. In both cases, a simple SELECT on primary key ...
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1answer
988 views

mysql, changing tables from myisam to ndb

Gents, Converting a table from myisam to ndb via: ALTER TABLE piwik_log_profiling ENGINE NDBCLUSTER; This will fail with: BLOB column 'query' can't be used in key specification with the used ...
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1answer
211 views

MySQL fulltext selection performance

I have 1.5M rows in a table. Following is the table create code: CREATE TABLE `jobs` ( `id` INT(8) NOT NULL AUTO_INCREMENT, `job_id` VARCHAR(50) NOT NULL DEFAULT '', `title` VARCHAR(255) ...
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3answers
527 views

What is the optimal solution for converting a database schema?

I actually want to get rid of the existing constraints in the database which I know sounds crazy but we are upgrading our application to a new framework which relies on the foreign key constraint ...
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1answer
3k views

mysql table very large size although it doesn't have a lot of records

I have drupal website, one of the tables is cache_form. I have a cron to DELETE FROM cache_form where expire < UNIX_TIMESTAMP(NOW()); which works fine. The size of cache_form.myd is 4.9G ...
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1answer
264 views

Best way to add a new column to a large table? (MySQL - MyISAM)

Here's more info on the table that needs to be altered: 15GB size MyISAM table with Index around 5GB Over 100 million rows MySQL 5.1 on RHEL 5 with 4GB RAM Currently live online What's the best ...
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1answer
5k views

Do you still use MyISAM or prefer Aria storage engine?

If Aria storage engine (previously called Maria) is the "new" MyISAM, which supports transaction and automatic crash recovery: Why still use MyISAM ? Should changing storage engine from MyISAM to ...
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2answers
142 views

Whats row size in mysql?

i mean what does it mean ?, i have mysql db and table in myisam and it shows Space usage Type Usage Data 1.3 GiB Index 429.1 MiB Total 1.7 GiB Row Statistics Statements Value ...
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1answer
4k views

Configuring MySQL (my.cnf) for MyISAM and InnoDB

I want to convert some (not all) the MyISAM tables to InnoDB. Here is my current my.cnf: pastebin.com/FW8YXtLQ What would be the best configuration? (need to add InnoDB settings, byecause there are ...
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1answer
1k views

Will OPTIMIZE TABLE have any impact on my data?

I'm having issues with a database that is getting quite slow. The analyzer in phpMyAdmin recommends that I run OPTIMIZE TABLE on my tables. But before doing so, I would (of course) like to know if ...
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1answer
2k views

mysqlcheck to optimize innodb tables — performance/scheduling

I'm attempting to optimize tables on a very large, production database server. I'm looking for statistics or benchmarks on how long it will take for certain sized databases/tables. Is there a ...
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1answer
255 views

Converting Heap to MyISAM issue

At work we have a problem that has now occurred more then once. Problem is that query is in state of converting HEAP to MyISAM and it paralyzes our server( query in this state is not able to kill ...
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1answer
477 views

Issue moving database between servers (cannot find .frm file even though it's there)

I used MAMP on my local machine to make a little site with a mysql database. I moved all the site files over the to server. Great. The name of my database is roster and it has one table called users. ...
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1answer
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why/how does the number of matched columns influences the way of excecuting a query

Imagine the following situation: Table A uses MyISAM and contains 4 fields (text) with a combined FULLTEXT-index. FULLTEXT fulltext1 | fulltext2 | fulltext3 | fulltext4 Table B uses InnoDB and ...
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1answer
360 views

Can MySQL 5.1 read a MySQL 5.5 MyISAM file?

We're in the middle of an upgrade from mysql 5.1 to mysql 5.5. Our only remaining holdout is the master, at 5.1, while all the slaves are at 5.5. However, we have a stats process that runs on an ...
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1answer
861 views

mysql: find column data size on disk

I have fairly large MyISAM table with longtext field in it Table size is somewhat 16GB. I need to know if clearing this column in old records helps to keep table small I can retrieve table wise ...
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1answer
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Repairing Myisam Table when there was no additional Disk space & Table corrupted

I had a table which MyIsam as storage Engine contains million rows. There is a purging task and need to remove 35 days old data. i measured up the rows in following manner : mysql> select ...