MyISAM is a non-transactional storage engine for MySQL. It provides high-speed storage and retrieval, as well as fulltext searching capabilities. Also, is the default storage engine type for version prior to 5.5.
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30 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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1answer
56 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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2answers
222 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 ...
3
votes
1answer
80 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, ...
3
votes
1answer
342 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 ...
3
votes
2answers
122 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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1answer
175 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
216 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 ...
4
votes
2answers
4k views
Why is MySQL is creating so many temporary tables on disk?
Can any configuration mistake lead to creating too many temp tables by mysql..mysql tuner shows
Current max_heap_table_size = 200 M
Current tmp_table_size = 200 M
Of 17158 temp tables, 30% were ...
1
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1answer
151 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 ...
1
vote
2answers
226 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 ...
2
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2answers
3k views
Why do MySQL tables crash? How do I prevent it?
I'm the Administrator of a Moodle site which had its Users table corrupted and it became unusable.
Luckily, a simple REPAIR TABLE mdl_user made it work back again. The thing is that I don't know why ...
50
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8answers
23k views
What are the main differences between InnoDB and MyISAM?
What are the main differences between InnoDB and MyISAM?
2
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1answer
319 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 ...
4
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1answer
124 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 ...
1
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0answers
68 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 ...
1
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1answer
71 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 ...
6
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1answer
216 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
486 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 ...
4
votes
1answer
222 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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0answers
61 views
Unable to set table-specific privileges
I want to give a user access to only a few tables. I execute this query:
GRANT SELECT (credits_features_csgo, steam_code, credits_csgo, userid,
credits_forum, credits_features_tf2, credits_tf2, ...
4
votes
1answer
124 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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1answer
55 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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1answer
74 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 ...
2
votes
1answer
206 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 ...
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2answers
694 views
Some queries slower in MySQL 5.5 than 5.0?
We have an exceptionally inefficient process (1.3 million selects, 232k updates) that I'm now recoding to be 1 select and 50 updates. In the meantime, though, today's process ran.
We recently updated ...
5
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2answers
388 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
votes
1answer
1k 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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2answers
355 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 ...
1
vote
0answers
70 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
168 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 ...
6
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1answer
2k 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 ...
4
votes
2answers
3k views
Using multiple cores for single MySQL queries on Debian
I am running a MySQL server for tests on a VM (VMWare) with Debian as guest OS. The guest has four emulated CPU cores, so I set thread_concurrency to four.
I am doing expensive joins on large tables, ...
1
vote
1answer
79 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) ...
1
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1answer
120 views
Optimizing table and choosing storage engine
Having the follow MyISAM table:
+----------------------+-----------------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
...
2
votes
2answers
585 views
How to copy a MySQL database which is a mixture of InnoDB and MyISAM to the same server?
Because mysqldump takes forever, we decided to just move around the files. Because the 2 databases are on the same server, a cp will be fast.
The problem is, from research, MyISAM is okay with being ...
2
votes
1answer
187 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
113 views
How to interpret explain sql?
SELECT DISTINCT TB.ID, TB.Latitude, TB.Longitude, 111151.293413 * SQRT( pow( - 6.185 - TB.Latitude, 2 ) + pow( 106.773 - TB.Longitude, 2 ) * 0.988392289802 ) AS Distance
FROM `tablebusiness` AS TB
...
4
votes
2answers
274 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 ...
3
votes
1answer
454 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 ...
0
votes
1answer
380 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 ...
2
votes
1answer
344 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 ...
2
votes
1answer
1k 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, ...
1
vote
1answer
589 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 ...
2
votes
2answers
293 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 ...
5
votes
1answer
345 views
Can I have an InnoDB master and MyISAM slaves with Full-Text for searching?
I'd like to use InnoDB on the master, for its transactional ability, but MyISAM on the slaves for the full-text search ability. Is this possible?
2
votes
1answer
91 views
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 ...
1
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0answers
142 views
How to speed up this query
MySQL doesn't have nearest neighbor search so. So I try to come up with a "distance" that's reasonable so the number of returned query is around 20-200. That way innodb doesn't have to compute ...
4
votes
2answers
5k views
way to prevent queries from waiting for table level lock
We've encountered a problem after moving the database of our customer to an extra server. This should have had positive effects on the site's performance, but there is a problem with table locking in ...
3
votes
4answers
2k views
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
...
