The tag has no usage guidance.

learn more… | top users | synonyms

1
vote
0answers
29 views

howto read/interpret “show engine innodb mutex” output?

We use a 3 node Galera cluster with version 5.5.41-MariaDB-wsrep MariaDB [(none)]> show engine innodb mutex; +--------+---------------------------------+------------------+ | Type | Name ...
0
votes
3answers
3k views

Migrate Jira to MySql - Unknown system variable 'storage_engine'

I'm migrating JIRA in Windows from HSQL to MySQL and I got stuck with the message Unknown system variable 'storage_engine'. Though I created a backup, installed MySQL and copied J connector to libs ...
10
votes
1answer
501 views

Do databases make a delete and an insert when having to update rows?

So today a professor told us that when the database has to make an update, internally (at low level) it makes a delete and then an insert with the updated fields. He then said that this is something ...
1
vote
1answer
151 views

Fastest engine for Mass Updates (only updates done on table)

I have a table of 2 columns and 60 million rows. I want to update the table by incrementing one field by 1 on various different rows (This is the only type of operation that will ever be done on the ...
2
votes
2answers
27 views

MySQL lock on MEMORY storage engine, when does it apply?

I want to use MySQL MEMORY storage engine to handle my PHP session variables (actually I already implemented it but since all my tests are being done by a single user, me, I am unable to notice this). ...
1
vote
1answer
27 views

Does TokuDB need any regular cleanup/maintenance?

PostgreSQL has vacuum and InnoDB has purge. Does TokuDB have any required maintenance/cleanup operations? I couldn't find anything in the online docs: ...
9
votes
2answers
4k views

MongoDB MMAPv1 vs WiredTiger storage engines

In mongoDB3 appeared a new storage engine: WiredTiger. Yet, MMAPv1 is still the default choice in Mongo. One might not be better than the other, it's often a matter of use case and choosing the ...
0
votes
0answers
67 views

Is the Aria storage engine really crash safe?

I maintain a PHP/MySql app for a big customer. Many of the tables were on MyISAM b/c that was the default when I started. On a newer server running MariaDB, some of those tables kept crashing. ...
2
votes
1answer
32 views

Alternative ways to find tables with specific storage engine?

I have a VPS with three accounts and 5 db's. Recently I added MySQLTuner. All of my tables are MyISAM, but the results MySQLTuner are showing that I have 14 tables that use InnoDB. [--] Data in ...
2
votes
1answer
314 views

Mysqli prepare error: Unknown storage engine 'InnoDB'

I'm getting this error on my XenForo installation. Server logs show out of memory because of too many php processes opened up which cause mysqld to shutdown. The WordPress installation associated with ...
0
votes
2answers
49 views

What storage engine do I need - Mysql?

I have designed a database and came to the point of actually deciding which storage engine is better for my case. I estimate that during the first few years I would have around 100,000 - 500,000 ...
2
votes
1answer
83 views

SQLyog and MariaDB engine

I am quite new in MariaDB and I use SQLyog Community Edition as the frontend GUI. Whenever I create a new table, on the Engine dropdown, there is no XtraDB option. Is there any additional steps I am ...
3
votes
1answer
160 views

MariaDB Spider Engine Out of Memory

I had almost standard MariaDB with InnoDB engine working fine but I wanted to test out the Spider Engine + Sharding/Partitioning. I had a query which was passing fine on the MariaDB InnoDB for ...
0
votes
0answers
9 views

Database storage engine and performance [duplicate]

What will be the performance issue when I change my database storage type from MyISAM to InnoDB?
40
votes
4answers
72k views

Which is faster, InnoDB or MyISAM?

How can MyISAM be "faster" than InnoDB if MyISAM needs to do disk reads for the data? InnoDB uses the buffer pool for indexes and data, and MyISAM just for the index?
4
votes
2answers
217 views

Optimal engine for small lookup tables in MySQL

I have following question: I am designing web application with several dozens of small lookup tables: These tables usualy contain three columns (ID, Name, Description) and a couple of rows (mostly ...
5
votes
1answer
2k views

MongoDB 3.0 : Configure storage engine at collection or database level

I know we can configure the storage engine to be wiredTiger at instance level when we start mongod. But can we also select the storage engine to be different for different collection or database?
3
votes
2answers
993 views

How is it possible for mysql storage engine to be NULL?

I'm just reading a book and in one of the examples I get notices: That the engine in the information_schema.table is null, how is that possible? Can I create tables without any engine??, is there ...
0
votes
1answer
95 views

Change Storage Engine on Referenced Tables

i need to change storage engine from 'InnoDB' to 'MyISAM' on some tables of different databases. So i made a script file to do so: #!/bin/bash DATABASES=$(mysql -u XXXXX -pXXXXX --skip-column-names ...
5
votes
2answers
2k views

What storage engines work with Oracle?

http://en.wikipedia.org/wiki/Database_engine mentions about database engines aka storage engines. What all storage engines can be used with the Oracle database?
0
votes
0answers
347 views

I have changed table engines from MyISAM to Aria, should I change the database engine too?

I have changed all tables in my mariadb database from MyISAM to Aria (using adminer as tool), but the database engine is still shown as InnoDB. Should I change this to Aria, too? I did not choose ...
0
votes
2answers
1k views

Is there a way to enable MariaDB MEMORY storage engine for every table?

I am new to MariaDB and interested in using it because I want to use MEMORY storage engine for every table. I read MEMORY storage engine on mariadb.com and it seems like I had to specify storage ...
1
vote
1answer
221 views

How do I create fractal index using tokudb engine?

I install MariaDb and configured it to use TokuDb Engine. I need to use Fractal-Index Built-in on TokuDb Engine. I have create my index as follow: ALTER TABLE `table__name` ADD INDEX ( `column` ); ...
1
vote
1answer
432 views

How to export mysql databases with different ENGINE?

I'm setting up MySQL Cluster. As it uses ENGINE=NDBCLUSTER, how could I export my databases from MySQL Server specifying the ENGINE? Is there a way to do this? All my tables are MYISAM
1
vote
1answer
87 views

How Much Resources Does the BLACKHOLE Storage Engine Consume?

I'm going to add a MySQL Relay Slave which use BLACKHOLE Storage Engine. The relay slave will just filter some databases binlog to downstream slave. Our MySQL Master generates about 15G a day in ...
5
votes
1answer
710 views

Is it Possible to Recover Data from a BLACKHOLE table? [closed]

I had created table with engine BLACKHOLE basically the BLACKHOLE storage engine acts as a “black hole” that accepts data but throws it away and does not store it. Retrievals always return an empty ...
21
votes
3answers
18k views

What are reasons *not* to use the MEMORY storage engine in MySQL?

I recently discovered that MySQL has a "memory" engine that I wasn't aware of (most of my database work is for hobby projects so I learn what I need as I go). It seems like this option should give me ...
17
votes
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 ...
1
vote
1answer
1k 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
1answer
171 views

Aria engine - changing block size

It's possible to change aria_block_size from default 8192 without recreating tables? I want try 1024 or 2048 but after change in my.cnf and restart mariadb I got this errors on aria tables: #138 - ...
0
votes
2answers
1k views

Inserting into mysql table with archive engine “duplicate key” error

I am trying to archive some files using mysql archive engine. I am using this query to insert file contents: insert into test_table (id,arch) values (123,'FILE_CONTENT') After inserting 2 records, ...
1
vote
1answer
79 views

Where Mysqldump gets data from

How mysqldump is processing backup? From which all files is it reads data for creating dump? Is the process differs if storage engines are different?
3
votes
4answers
14k views

How to Add Federated engine after installing Mysql

I have Mysql 5.5.18 and upon show engines: show engines; +--------------------+---------+------------------------------------------------------------+--------------+------+------------+ | Engine ...
2
votes
1answer
741 views

TokuDB database size unknown in phpmyadmin

In mysql server, I installed the TokuDB storage engine. I converted database engine InnoDB to TokuDB, but my table sizes show unknown in phpmyadmin.
3
votes
1answer
1k views

How to convert innodb engine tables to tokudb engine

Hi I want to migarate my server newly installed tokudb engine. i want to convert each table of database from innodb to tokudb. How can I do that using sed command ?
3
votes
2answers
1k views

Question about non-clustered index storage in SQL Server

I have a table people with two non-clustered indexes. create table people( id_person int, first_name varchar(50), last_name varchar(50), city varchar(100), state char(2), zip_code int ) CREATE ...
0
votes
1answer
731 views

Mysql federated engine table creation error

I am trying to create a federated table on my local machine which suppose to connect to my another machine which also in my local network. I have enabled federated engine on both machines and is shown ...
1
vote
1answer
1k views

Unknown storage engine 'XtraDB'

I installed Percona Server 5.6.12-rc60.4, when I want create table such as : CREATE TABLE IF NOT EXISTS `mydb`.`table` ( `id` INT NOT NULL AUTO_INCREMENT , `title` VARCHAR( 64 ) NOT NULL , PRIMARY ...
1
vote
2answers
203 views

Which MySQL engine should i use where most operations are read operations

I want to develop an application for which i will need a database to store data. I am using MySQL as backend. My question is Which MySQL engine should i use? Well, i have mentioned some important ...
1
vote
1answer
731 views

Does SQL Server check disk space before allocating a new page?

I have a bet with my old boss. I bet her that SQL Server, when allocating a new extent, always allocates from the buffer pool and never checks to see whether there is some place on disk where the ...
6
votes
3answers
3k views

Is MariaDB a suitable drop in replacement for MySQL on a standard LAMP stack?

I've been wondering lately what (if any) are the improvements available in MariaDB over 'conventional' MySQL? I understand that where platform interoperability and/or backwards compatibility may be ...
2
votes
1answer
487 views

Issues converting MyISAM table to InnoDB (auto column issue)

I'm having issues trying to convert a table from MyISAM to InnoDB in MySQL 5.6. The following is the table dump: -- -- Table structure for table `companies` -- DROP TABLE IF EXISTS `companies`; ...
1
vote
1answer
531 views

Is there a query to set a table's engine to innodb if it's not already?

I can set a (MyISAM) table's engine to InnoDB using the query: alter table tablename engine=InnoDB which takes some time to complete for large tables. It appears though that if I run the same query ...
1
vote
1answer
137 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 ...
2
votes
1answer
426 views

Is the Memory engine adequate for a read intensive/lookup table?

I have an InnoDB table with just two columns, a VARCHAR(20) and a DATETIME, and around 4M rows. This table serves as a blacklist for other tables, and is truncated and recreated from a csv file from ...
3
votes
1answer
445 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, ...
1
vote
1answer
586 views

Can I use symlink or data directory for ARCHIVE MySQL tables?

All mention of either using a symlink or data/index separate data directories state that MyISAM is the only supported (https://dev.mysql.com/doc/refman/5.5/en/symbolic-links.html). However, I found ...
0
votes
2answers
420 views

Best MySQL storage engine for read heavy table with two indexes

I have a pretty big MySQL table (70G) with about 15 columns and 1.5M rows. There is one index on the autoincrement id and one on a foreign key (integer). Apart from that there are several VARCHAR and ...
12
votes
1answer
925 views

Slot Array and Total Page Size

I continue to read in many forums and on many blogs that a page is comprised as shown below: Page Size: 16 x 512B = 8192B Page Header: = 96B Maximum In_Row Row: = 8060B This leaves ...
5
votes
1answer
268 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 ...