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.

learn more… | top users | synonyms

0
votes
3answers
787 views

How to determine the optimal sort_buffer_size?

I read from a sample configuration file which says the following: # Sort buffer is used to perform sorts for some ORDER BY and GROUP BY # queries. If sorted data does not fit into the sort buffer, a ...
1
vote
1answer
108 views

MySQL hangs in killed state

I have a strange situation where a mysql OPTIMIZE query will never end. After killinh it, it remains in the "killed" state. Scenario to reproduce: OS: CentOS 6.5 MySQL: 5.6 Engine: MyISAM (with at ...
1
vote
1answer
86 views

InnoDB to MyISAM Conversion Problem

I have a dedicated server based on CentOS 5 OS , mysql 5 and phpmyadmin I was trying to convert all database tables from InnoDB to MYISAM. I tried to do it by setting in /etc/my.cnf file the value ...
0
votes
0answers
215 views

How to recover a crashed MyISAM table which myisamchk couldn't recover?

We take db backup by stopping the database and then issuing a tar -zcf on the mysql data directory. When we restore the data directory on another machine and try to start the slave, the mysql error ...
2
votes
2answers
210 views

Why does MySQL fail to use an index effectively when LIMIT offset is large?

I do not understand when querying 5 rows from a table of 500,000 rows, the following query takes 0.00sec: SELECT id, username FROM Users FORCE INDEX (PRIMARY) ORDER BY id LIMIT 20,5; But querying ...
0
votes
1answer
119 views

Is searching an alternate index on a partitioned myISAM table concurrent or serial?

I have a myISAM table with 30 partitions. The primary key is a SHA1 hash value, which is also used in the partition selection function. I also have an alternate key - an autoincrement integer. Since ...
1
vote
1answer
281 views

MyISAM with Innodb in the same Wordpress database reduce performace?

My new Wordpress database all the Wordpress created tables use InnoDB engine and plugin created table use MyISAM. But older site database all the tables use MyISAM table engine. I use MySQL ...
0
votes
1answer
283 views

INSERT take too much time

I have in my MySQL DB a few tables Most of the time, I'm only doing INSERT in my db. I have up to 4 connections to the DB, each one inserting into a different table. There cannot be two connections ...
1
vote
2answers
316 views

MySQL views and table locking (5.1 MyISAM)

I have a large (160 million rows, 50GB) table in MySQL 5.1 using MyISAM. If I were to construct a view defined by a fairly complicated query, would a SELECT on the view lock the underlying table?
0
votes
1answer
56 views

Backup live MySQL database

I have a single MySQL database Server version: 5.5.35-cll MySQL Community Server (GPL) ENGINE is MyISAM I use 'mysqldump' to backup and restore the database. Size of the dumpfile is 3GB+ Once a ...
7
votes
2answers
469 views

How to drop empty tables

Is it possible to drop all empty tables from my huge database (mysql)? I'm looking for a sql command to automatically remove all those empty tables. Currently, I have 305 tables in my dataset, and ...
5
votes
1answer
1k views

MySQL 5.1 to 5.6: massive performance hit

Okay, this is possibly three questions. I want to move my existing MySQL 5.1 database using MyISAM to 5.6 using InnoDB for what I think are a host of obvious -- and possibly even good -- reasons. ...
3
votes
1answer
166 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 ...
0
votes
1answer
157 views

Upgrading mysql myisam 5.1 to mysql 5.6: force innodb on restore?

I inherited a DB using myisam on mysql 5.1 because of the need for fulltext search. I now read that fulltext search is available on mysql 5.6 innodb. Doing this would solve a lot of problems, as long ...
1
vote
2answers
186 views

Why does MySQL + Windows Server = crashed tables periodically?

Windows Server 2008 R2 x64 MySQL Server 5.6.14 x64 Is anyone else having an issue in where some tables are marked as crashed on a Microsoft Windows server? We have a couple of Windows servers (not by ...
0
votes
0answers
25 views

How to change a table's data directory

I tried to modify with ALTER TABLE, and as I found from the official documentation: ALTER TABLE ignores the DATA DIRECTORY and INDEX DIRECTORY table options. What other options do I have? ...
0
votes
0answers
87 views

.myd and .myi versus .frm and .ibd

I'm new to MySQL.I have trouble finding the .frm files and .ibd files in Windows 8 Explorer.They seem hidden and I have to find them using 'Find' and 'Open File Location', not sure how to make these ...
2
votes
1answer
65 views

How safe is it to widen a column in MySQL?

Apologies for the simple question but SQL isn't really my forte, and I want to be sure I don't shoot myself in the foot. A MySQL database I volunteered to help maintain has a table that looks like ...
1
vote
0answers
158 views

Missing rows in MyISAM tables with 10-20 billion records

I've got 2 tables with 10-20 billion records each. Currently these are in MyISAM (MySQL). They only require to be built and indexed once, after this only SELECT is used. They are currently ...
0
votes
1answer
424 views

My database keeps crashing on startup how can i repair it without it running?

I've got some problems with my database. I hope somebody can help me out. Problem: The database keeps crashing on startup. In my log i see a couple off these errors: [ERROR] /usr/libexec/mysqld: ...
0
votes
0answers
89 views

What are the steps to change tables engines from MyISAM to InnoDB?

I have a Datebase with 10MB size . The Tables' engines were MyISAM (table-lock level). So I deiced to change them to InnoDB (row-lock level). I used the sql query for each table : ALTER TABLE t ...
0
votes
1answer
40 views

is it possible to set engine for database (not the tables)?

There are about 250 tables in my database and they all have InnoDB engine. I imported them into a server. They were imported and were displayed in the tree structure of phpmyadmin (under the ...
1
vote
1answer
109 views

Need to optimize simple SELECT query for InnoDB table with 2million rows

I'd like to make this query the fastest possible, since it's called really often. SELECT login_events.id FROM login_events WHERE ( DATE(created_at) >= DATE(CURRENT_DATE) AND person_id = 1 ) ...
0
votes
1answer
60 views

Few Insert queries rollbacked due to system crash

Well, this problem occured to me first time. Yesterday, one of our mysql system server crashed and when it restarted last few inserts were completely rollbacked. I am sure that they were proper ...
0
votes
2answers
60 views

MySQL using swap during conversion to InnoDB

I'm trying to convert some MyISAM tables in my database to InnoDB (MySQL 5.1). The server has quite a bit of memory (96G), and the tables that are giving me problems can be on the order of 50 millions ...
1
vote
2answers
477 views

Setting default CHARSET and DB Engine

I recently updated my server's database system from MySQL to MariaDB. After update, everything works well. But, when I went to phpMyAdmin, the default charset and types are changed: At the end of ...
0
votes
2answers
96 views

Should we explicitly lock MyISAM tables or is it implicit…?

Does MyISAM tables automatically lock a table for each select or insert statement .... I mean if I query the database as select * from tablename then does the MySQL engine first lock it for read ...
0
votes
1answer
522 views

how to set bulk_insert_buffer_size in mysql?

I want to set bulk_insert_buffer_size variable for insert. I searched from other pages too, all they are saying about my.cnf. But there is no my.cnf in my system. I checked my.ini and there is no such ...
0
votes
0answers
49 views

How to get rid of the table lock in MySQL

I have a database for my website the website have a betting game(using insert and update queries) and the other pages of the website are using (select, insert and update queries). When a user make a ...
1
vote
1answer
575 views

Timeout on ALTER TABLE table ENGINE=InnoDB - is table still converted?

I'm converting tables in an old MYISAM database to InnoDB to increase robustness in case of power loss etc. I'm using Mysql 5.5.x Before doing the production system, I am doing a trial run on a copy ...
1
vote
3answers
540 views

Converting live MyISAM table to InnoDB

I have a table that tracks web traffic. The table is constantly written and read from. Since table is pretty big in size I have to make sure the application will not "freeze" in the process of ...
0
votes
1answer
164 views

Backing up MySQL w/MyISAM on Amazon RDS

So, for various good reasons, we're maintaining a mySQL database using a MyISAM engine on Amazon RDS. I've just taken over this application, and I'm concerned we're not getting good backups, since ...
0
votes
1answer
113 views

When and how would MyISAM concurrent insert = always be a problem?

I wish to set concurrent_insert to always on a MyISAM log table, so that inserts wouldn't have to wait for selects to perform when there are some holes in the table. We're talking about 10-20 inserts ...
1
vote
1answer
179 views

Debugging error report percona 5.6

I'm running percona 5.6 on a new centos 6.4 server. Things seem to work OK. I personally only really use InnoDB tables for my databases, but only the standard 'mysql' table is in MyISAM format. I ...
0
votes
0answers
187 views

Improve Speed of MySQL Database Import

I'm importing around 44 GB (14 million rows) of information into an InnoDB MySQL database, and I'd like to do so in a reasonable timeframe. Since I'm doing this on a personal computer, I only have 8 ...
1
vote
1answer
214 views

Mysql Performance tuning for myisam tables.

Folks I have a 4-core MySQL server with 4 GB of RAM, holding 19 MyISAM tables (total: ~164GB of data) and 32 innodb tables ( 5mb ) and we use it to process CDR files( basically call detail records ...
0
votes
1answer
205 views

MySQL select by primary key against 100M of records within 30ms

I have no expirience with MySQL and database performance tuning in general. Wondering whether it is possible to perform a large number of selects against 100 millions of records by primary key within ...
2
votes
1answer
200 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. ...
0
votes
0answers
59 views

Performance setting for MyISAM tables - my.cnf file

I have a 4-core MySQL server with 4 GB of RAM, holding 19 MyISAM tables (total: ~164GB of data) and 32 innodb tables ( 5mb ) . QUESTIONS Since the databases size is smaller than the available ...
1
vote
1answer
66 views

MySQL command querying all MyISAM database

I would appreciate if anyone could help me of what's the proper command in MySQL to query all database for having "MyISAM" engine. I need to convert all DB & tables from MyISAM to InnoDB.
1
vote
1answer
545 views

Spatial Index on an InnoDB table

I have a database which is in InnoDB, because I wanted consistency (cascading delete). Now, I want to use spatial indexes for selecting rows ordered by geometric distance. However, spatial indexes ...
1
vote
1answer
281 views

MyISAM vs InnoDB for Forums [closed]

I want to design a forum script with MySql. Which database engine would have better performance? MyISAM or InnoDB ?
0
votes
1answer
6k views

What is causing Waiting for table level lock errors?

We got the database hanging twice already and trying to find a cause. show processlist Waiting for global read lock | INSERT INTO {myisam_table} ... In here the disk space was full so we thought ...
2
votes
1answer
61 views

How to go about modeling the main object of relationship?

I'm using MySQL and MyISAM tables. I have a bunch of objects that I want to group together 1 object belongs to 1 and only 1 group 1 group can have many objects 1 group has 1 required main object ...
1
vote
1answer
1k views

Merge multiple tables in a database

I have a MySQL database with table names like 1,2,3... upto 1000 Each tables have 2000 rows and has the same structure. This is how all my 2000 table's structure look like id,url,title,content id ...
2
votes
1answer
366 views

Is it safe to kill ANALYZE TABLE query on a MyISAM table?

I have a huge MyISAM table that is blocking my application. I frequently find ANALYZE TABLE queries running on that table. I guess that's because a join is being performed on the table or at least an ...
0
votes
1answer
274 views

MySQL MyISAM index causes query to match no rows; indexes disabled, rows match

I created a table and index as described in this SE post, but when I query the table for a particular ID, no matches are found. When I disable the index, matches are found. Commands ran: CREATE ...
3
votes
1answer
166 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 ...
0
votes
1answer
71 views

MyISAM table is not working as expected in MySQL

mysql>show processlist; +-------+------+------------------------------+---------------------+---------+-------+-------+------------------+ | Id | User | Host | db ...
2
votes
2answers
3k views

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 ...