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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406 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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2answers
288 views

Recommended structure? %70 write %30 read. 10M row. 200 query/sec. Select, update, insert, search

Followings are what I need to do on my project: 1- If a search term is new and unique, then add the search term 2- Show lastest searched 1000 search terms (I don't need to store dates of all search ...
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2answers
888 views

Need help in restore some rows into mySQL database frm myd myi

I am using one mySQL database for several sections of the website and one of the section is not working, when I go to the link of that section it gives the error "1146 Error @ Line 39: Table ...
2
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1answer
413 views

myisampack running really slow for large DBs

I was going through compressing a bunch of archival myisam tables using myisampack It was making decent progress until it got to the most recent tables. The overall database is a set of archives for ...
2
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1answer
89 views

Moving the binary location of MySQL for replication

Is it possible to move the contents of /var/lib/mysql when setting up replication instead of doing mysqldump > for export and mysql < for insert on the slave, because in our current setup it takes ...
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3answers
2k views

MySQL tables/databases into different disks

I am aware that there is a possibility to have a single database server with many tables/databases, and you can separate some of those tables/databases into separate disks. Lets say you have 5 ...
2
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2answers
775 views

MyISAM table keeps crashing. What are my options?

My MYSQL table is very large (250GB, around 200M rows). Recently I've been putting it through a lot -- parallel processes that do a large number of reads. It has started locking and crashing with ...
3
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1answer
1k 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 ...
5
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1answer
940 views

Quick MySQL Backup (1 file per table)

I asked a relevant question few months back and got answer with wide variety of options for backup. But this time I have different scenario and I have got a database with 7 tables and 1 of them has ...
4
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1answer
2k views

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 ...
2
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1answer
2k views

importing myisam 5.0 database into a 5.5 innodb server

I have MySQL 5.0 and 5.5 servers (but not a 5.1 server). The 5.0 server is myisam only, the 5.5 default is innodb. I need to move a database from the 5.0 server to the 5.5 server. The database is ...
4
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2answers
800 views

Less RAM than Index_length MyISAM

I'm working on a database to store "time series" data (the value of X was Y at this time). The rows themselves are very small and static in size, with the primary key consisting of two smallint ...
2
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1answer
4k views

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 ...
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2answers
1k views

All columns of table should be indexed or not mysql database?

I am having one table with 4 columns. I that one is primary key and other three columns are references to columns of other tables. I am using join of these four tables for search filter. These joins ...
4
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2answers
2k views

How to optimize the my.cnf of a MySQL server that mixes InnoDB and MyISAM tablespaces?

I have a database that, because of some issues, I needed to convert some tables from MyISAM to InnoDB. I basically did this: set sql_log_bin = 0; set sql_mode = 'STRICT_ALL_TABLES'; ALTER TABLE ...
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2answers
4k views

Any gotchas at all with converting from MyISAM to InnoDB?

I'm ready to move from MyISAM to InnoDB but wanted to know if there was a full list of things to look for? For example, I haven't seen any list mention that running DISABLE KEYS on an InnoDB table ...
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vote
1answer
3k views

Write lock during mysqldump even using --lock-tables=false

When I try to dump an online database using --lock-tables=false, others cannot update the table. Are there any methods to solve this? As I am using MyISAM, does --single-transaction for InnoDB help? ...
2
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1answer
4k 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 ...
3
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1answer
2k views

MySQL Config for Large MyISAM tables

I have to do some updates on myisam tables which have around 20 M records. Our server has 24GB of ram and 2 quad core xeon with 24 MB of cache. I want to know how I can change the my.ini file so I get ...
3
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2answers
5k views

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? ...
2
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2answers
1k views

Which first: upgrade mysql version or convert storage engine?

I inherited a production mysql server at 5.0. It uses MyISAM exclusively. It is not a high volume database but it does have some large datasets. I am planning on: upgrading to 5.5 converting ...
2
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2answers
572 views

Any problem will all InnoDB and one MyISAM table?

I have a MySQL 5.5 DB with all InnoDB tables. For some reason, one of the developers decided to create a MyISAM table. It is a log table for user sessions. I don't see why we should mix in a MyISAM ...
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2answers
8k views

Set up a MySQL slave using mysqldump to get the initial data

I have a master database which already has some data in it. The tables in the master database include both MyISAM and InnoDB engines. Now I want use mysqldump to dump the initial data of my slave ...
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2answers
2k views

Why does MyISAM support FULLTEXT Searching and InnoDB does not?

I know the basic differences between the MyISAM and InnoDB engines. In MySQL 5.6 beta, InnoDB will support fulltext search. But, I wonder why previous versions of InnobDB didn't support FTS? My guess ...
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1answer
3k views

MySQL MyISAM Locking question

It was my understanding that MyISAM uses table locking during inserts and updates. To me that meant that read and write by other queries on that table is disallowed until the first insertion or update ...
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1answer
4k views

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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3answers
608 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 ...
1
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1answer
767 views

How to Prevent an Ever-Growing index file (MyISAM engine) From Causing Disk Fragmentation in Windows (NTFS partition)?

We have a keep-growing table which using MYISAM storage engine. Almost every half year, this table will crash, and need to be repaired. I checked the defragment result reported by windows ...
5
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1answer
799 views

Should I use a storage engine other than MyISAM to optimise these tables or should I get better disks?

There's a production database I'm working on, whose 4 largest tables contain between 4 million and 10 million rows each and about 15 fields each, with indexes on different field types (numbers, ...
3
votes
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
4k views

Consistent logical backup of databases that use MyISAM and InnoDB engines

I have a question regarding the logical backup of MySQL databases that use both MyISAM and InnoDB. The mysqldump utility supports these two options: --single-transaction - Creates a consistent ...
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3answers
10k views

Best of MyISAM and InnoDB

Is it possible to make InnoDB to use indexes same as MyISAM instead of clustered index due to limitation of RAM while getting benefit of its concurrency performance?
3
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3answers
609 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 ...
5
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4answers
5k views

Benefits of table level locking

What are the benefits of table level locking which is used by the MyISAM storage engine? Row level locking has lots of benefits like concurrent updates and reads that do not lock the table. Edit Its ...
4
votes
2answers
3k views

Preordering the table by a specified column

I have a table and I am always getting the data by ordering a column. In my case, I order by datenum. However, the selection is so slow because of the ordering. Is it possible to order the table ...
14
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2answers
4k views

Rows missing after online conversion from MyISAM to InnoDB

We have a reasonably small database that we wanted to convert from MyISAM to InnoDB. Being database noobs, we just converted (using alter table) without even taking the site down. Now that the ...
1
vote
1answer
459 views

Why did the MySQL Storage Engine Change on Restore in one scenario?

In my production database life, there was one tragic incident when the MySQL engine type was accidentally changed from InnoDB to MyISAM on restoring a recent backup. The result was that all ...
3
votes
2answers
707 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 ...
1
vote
1answer
147 views

MyISAM table row size is bigger than the sum of all the columns size?

I have a table: CREATE TABLE `playlist` ( `pid` int(11) unsigned NOT NULL, `mid` bigint(21) unsigned NOT NULL, `status` tinyint(1) NOT NULL, `add_time` int(11) unsigned NOT NULL, ...
5
votes
3answers
413 views

MyISAM Performance: Join Decomposition

in High Performance MySQL on page 159 they talk about breaking up complex queries into simple ones: Converting SELECT * FROM tag JOIN tag_post ON tag_post.tag_id=tag.id JOIN post ON ...
2
votes
1answer
446 views

MySQL MyISAM Table Locking and Delayed Inserts for Webserver Access Logs

We will install a webserver that writes access logs to a MySQL table. Access logs of course will get really really big, so this will be a separate MySQL instance from the regular data and we will more ...
16
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3answers
8k views

Is it common practice to mix InnoDB and MyISAM tables on same server?

I've got a single database of about 4.5GB running on a server with 8GB RAM. The vast majority of the tables are MyIsam (about 4.3GB), but I'm soon going to be converting some of them to InnoDB. (It's ...
16
votes
2answers
22k views

How can I change the default storage engine in phpmyadmin?

I use InnoDB almost exclusively in my applications. However, if I'm not careful when setting up the table, I forget to change it and phpmyadmin sticks me with MyISAM. Is there a way to change the ...
97
votes
9answers
87k views

What are the main differences between InnoDB and MyISAM?

What are the main differences between InnoDB and MyISAM?