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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LOAD DATA INFILE on a MyISAM table blocks user read-queries, can we get around this?

I've got a large reference table, 100GB, in a MyISAM table, load it up from scratch goes well (4ish hours) using LOAD DATA INFILE. But we have 1GB each day we want to update in a batch process using ...
3
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1answer
169 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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2answers
267 views

Bypass MyISAM table lock

I have a big MyISAM table with a fulltext index for searching. Problem is that inserting data into that table results in a table lock and in the meantime no other sql query can perform any action ...
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1answer
228 views

Why do MySQL MyISAM table indexes go out of date?

I have few MyISAM tables, where only the auto_increment primary key is up to date with the number of columns, but not other indexes. Any idea, why this happens?
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939 views

MySQL Table not repairing

Table info: Database name: user_motiva Table name: wp_options.frm wp_options.MYD wp_options.MYI wp_options.TMD when I do a mysqlcheck -r --all-databases it gets hung on that table even if you ...
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2answers
780 views

Unable to change engine to MyISAM in MySQL

I have installed MySQL 5.6.10 on Mac OS X 10.6.5. My issue is that MySQL is using InnoDB as its default engine. I have checked following engines are supported in MySQL: show engines\G ...
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1answer
42 views

Which text-index I should create for xooops engine to achieve better search results?

In one of projects we use xoops engine to manage content. In mysql slow query log most of queries are following : SELECT p.uid,f.forum_id, p.topic_id, p.poster_name, p.post_time, f.forum_name, ...
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497 views

View dropped, now shows as table “in use”, can't drop

I have a view on a MySQL/MyISAM setup, then the underlying table had a column dropped, and made that view invalid. I tried dropping the view so I could recreate it, then MySQL said it was a table ...
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1answer
519 views

How does mysql deal with queries that touches myisam and innodb tables?

In our mysql database, we use both myisam and innodb tables, though there are more myisam tables. QUESTIONS If a query involves both myisam and innodb tables, will the query use table lock or row ...
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213 views

Does MySQL's MyISAM use cache before insert?

I want to test two different Disks, one of them is HDD and another is SSD I use exactly same information and app for both servers. They are exactly same, just one of them is SSD and another is HARD. ...
2
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1answer
992 views

Unique insert performance: Primary Key vs Unique Index

I have a table of unique values (domains_unique), with collumn domain varchar(255), with more than 20 mil records. What's the fastest way to insert into the table, by keeping the domain unique ...
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1answer
98 views

Issue with Storage Engine

Just got the below error in one of the slave. I just Googled it and changed the variable myisam_data_pointer_size from 4 to 6. Somehow, my ALTER TABLE was successful. Can you please let me know ...
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33 views

MySQL: optimal configs / methods for ALTER of large MyISAM table to InnoDB (17gb+) [duplicate]

I have a large MySQL (5.1) MyISAM table (13gb table, 4GB indexes - 40mm+ records) I'm going to be converting this table to InnoDB in a production environment. The DB is on a cloud server with ...
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2answers
331 views

MySQL: optimal configs / methods for ALTER of large MyISAM table to InnoDB (17gb+)

I have a large MySQL (5.1) MyISAM table (13gb table, 4GB indexes - 40mm+ records) I'm going to be converting this table to InnoDB in a production environment. The DB is on a cloud server with ...
1
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1answer
112 views

With MyISAM is there any index size savings when using INT vs BIGINT?

There is obviously a four byte per row space savings in a data column when using INT vs a BIGINT type. But I have been trying to figure out if there is also any space savings for myisam indexes on ...
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1answer
138 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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2answers
236 views

Using MyISAM for reading and InnoDB for writing data

I read many articles about comparisons of MyISAM and InnoDB from performance point of view and I decided to use MyISAM for reading data and InnoDB for writing data. I want to use two structure like ...
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2answers
4k views

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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1answer
415 views

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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3answers
4k views

MySQL LOAD DATA INFILE slows by 80% after a few gigs of input with InnoDB engine

I'm loading a 100GB file via LOAD DATA INFILE. I've had good success with MyISAM, a few hours and done. I'm trying it now using InnoDB. The load starts fast at over 10MB/sec (watching the table file ...
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1answer
463 views

MySQL: To use MYISAM or INNODB engine? (plot twist enclosed)

We use INNODB for all of our tables, but I have one special table, a 100+ GB reference table (only read-queries against it). We are loading changes to this table in a nightly batch job using LOAD ...
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1answer
215 views

Set up replication and migrate to InnoDB with low downtime

Current situation is this: I have a large legacy DB using only MyISAM tables, the size of whole DB is 4GiB, one of the tables contains over 10 million rows, so it is pretty large. The database is ...
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177 views

Dynamic MySQL partitioning based on UnixTime

My DB design includes multiple MYISAM tables with measurements collected online, Each row record contains auto-incremented id, some data and an integer representing unixtime. I am designing an aging ...
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1answer
147 views

mysql freeze/crash on JOIN

here is query: SELECT nw.news_id, nw.title, nw.description, nw.url, nw.date, nw.image, nw.status, src.title as src_title, src.keyword as src_keyword, src.url as src_url, src.icon as ...
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1answer
171 views

Which MySQL storage engine is the most similar to ARCHIVE when that is not available?

I have a table that contains a log of events that is written to often and read very infrequently by comparison. I would love to use the ARCHIVE engine, because it is basically designed for exactly ...
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1answer
551 views

LOAD DATA INFILE blocks on concurrent use against MyISAM tables

I'm having trouble loading data into MyISAM table(s) concurrently using LOAD DATA INFILE. The loading operation works fine in isolation. Trying to do LOAD DATA INFILE operations concurrently, blocks ...
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2answers
534 views

Repair MySQL table without downtime

We have a corrupt MyISAM table in our production MySQL database. Is there a method for repairing this table without locking it? We were considering using a method similar to Facebook's Online Schema ...
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1answer
890 views

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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2answers
1k views

MySQL not responding, Writing to net status

I just had to reboot MySQL to regain access to some of my website. It had under 300MB of RAM used. Another product was working fine though, accessing it's own tables which are InnoDB. Here's the show ...
2
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1answer
734 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
93 views

How can I reinitialize some MyISAM tables without restarting MySQL?

I'm using rsync to copy some measurement data from one PC to the server. Is it possible to load the new MyISAM tables without restarting the MySQL server?
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600 views

TRUNCATE TABLE statement sometimes hangs

Why does the TRUNCATE TABLE statement hang sometimes? What are the reasons for this type of issue? I am migrating from MySQL to MariaDB. This problem doesn't happen with MySQL, only with MariaDB. ...
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2answers
139 views

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
315 views

MYSQL MyISAM data recovery implementation

I am creating integration into eshop script, shop is using MyISAM tables and I need to implement something like transactions in InnoDB, what I actually need is full recovery of data after modifying or ...
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1answer
103 views

myISAM data loss at DELETE / INSERT

I have a linked table id_group | id_user. Every time I add a one or more users to a group I DELETE all the links and INSERT the users again including the new one(s). This is how the framework of the ...
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2answers
645 views

Choosing MyISAM over InnoDB for these project requirements; and long term options

Sorry for the long post, but I had to give as much info as possible to make this very vague question more specific. My project's aim is to let users search a (huge) database of variety of products. ...
3
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1answer
2k views

Is Percona xtrabackup the right choice for my 500GB MySQL backup?

I have a MySQL db with 500GB, consisting mainly of Innodb tables, and one big (200GB) MyISAM table. My current backup strategy is copying the db files to an external harddrive. This causes a downtime ...
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111 views

How can I force myisamchk to modify the original data file in case of duplicate keys?

In the documentation for myisamchk, it says: --quick, -q Achieve a faster repair by modifying only the index file, not the data file. You can specify this option twice to force myisamchk to ...
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2answers
182 views

What MySQL storage engine should I choose?

I have a database for my catalog webpage. Some tables are about 3GB with millions of rows. What engine should I choose for my database, InnoDB or MyISAM? There will only be about 1,000 new records ...
4
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1answer
164 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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2answers
1k views

MySQL how to release memory used up by SELECT

I executed an INSERT IGNORE combined with SELECT from large table. The SELECT took up 16GB of memory and went into SWAP before I terminated it with CTRL+C. INSERT IGNORE INTO sid(sid) SELECT sid ...
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1answer
91 views

Select ``,* from table?

I'm trying to upgrade our database servers to MySQL 5.5. In doing so, I'd like to convert all of our tables to InnoDB to take advantage of several performance benefits. However, we use VARCHAR(50) ...
3
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1answer
1k views

Proper tuning for 30GB InnoDB table on server with 48GB RAM

I have a 30GB 15M rows InnoDB MySQL 5.5.15 table. It is running on a server with many other MyISAM tables (300GB db). The system has 48GB RAM. Besides the default configurations, I've changed the ...
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1answer
239 views

MySQL table locks solution -> InnoDb / Partitions

I'm experiencing many table locks in a MyISAM MySQL table that is pretty big (Constx10xGB and 15M rows). It's mainly caused due many heavy inserts. My current thoughts to optimize: Changing to ...
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1answer
919 views

Unable to select the records from specific partition in mysql?

I've created a table using the following query, CREATE TABLE employees ( id INT NOT NULL AUTO_INCREMENT PRIMARY KEY, fname VARCHAR(25) NOT NULL, lname VARCHAR(25) NOT NULL, store_id ...
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148 views

Optimizing table and choosing storage engine

Having the follow MyISAM table: +----------------------+-----------------------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | ...
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608 views

MySQL INSERTs waiting for UPDATEs (MyISAM)?

In show processlist;, MySQL 5.5, we see that INSERTs tend to wait for UPDATEs to complete before they can proceed. This is on MyISAM tables. We tried INSERT HIGH_PRIORITY and UPDATE LOW_PRIORITY. ...
2
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1answer
479 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 ...
6
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1answer
3k views

When to switch from MyISAM to InnoDB?

We have a MySQL 5.0 server running all tables as MyISAM. We have two slaves that, in the last month, we have upgraded to MySQL 5.5. Their tables are also still MyISAM. My original plan was to upgrade ...
2
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1answer
1k 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 ...