InnoDB : MySQL's ACID-compliant Storage Engine

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2
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1answer
303 views

Does a database update force index rebuild regardless of updated field?

With MySQL (InnoDB), I understand that having indexes slow down UPDATE queries. I would like to know if this happens regardless of what fields are updated. For example, if I have a table with 20 ...
1
vote
1answer
269 views

MySQL no query cache hits

My database have been up and running for a while with query cache enabled, but there are 0 hits. I have tried to check the settings but I am not sure what the problem is. Using InnoDB. mysql> SHOW ...
2
votes
1answer
357 views

MySQL table indexes change location [closed]

Is it possible to move the MySQL Table indexes to another location rather than "datadir" ? for example a ssd drive or memory partition ?
1
vote
1answer
53 views

75% of RAM for Innodb_buffer_pool size

I have read many documentation including percona and MariaDB documentation where they recommend setting innodb_buffer_pool_size to 70-80% of RAM. My question is, is that total RAM or available RAM? ...
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 ...
1
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0answers
208 views

MySQL 5.6.19a InnoDB Concurrent Insert [closed]

I've looked through most of the threads on this topic but still had question I was hoping someone would be gracious enough to help with. I am seeing low CPU usage and write latency but transaction ...
1
vote
0answers
22 views

Need advice on optimizing database on a recurring basis

I have a search engine with approx 3.5 million rows in the searchable table. There are many suppliers that feed into the table each day, so primary keys are constantly being removed and added and the ...
4
votes
1answer
8k views

Amazon RDS MySQL 5.5 Innodb Lock wait timeout exceeded

Ever since we've moved to Amazon RDS, we've had some pretty crazy performance issues, and today we started having locking issues. Because of that, I figured it was just a timeout issue, and went to ...
0
votes
1answer
454 views

MySQL - Indexes deleted, reduced column size but table size increases

Here is the original table definition which contains 107547934 (~107.5M) rows CREATE TABLE `twitter_tweets` ( `id_str` varchar(100) CHARACTER SET utf8 COLLATE utf8_unicode_ci NOT NULL ...
0
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0answers
126 views

How to notice data lost in innodb engine

I have a web-application installed in some desktop pc, and I experienced some troubles with mysql innodb. In case of hardware fault (disk failure) or just power fault I lost many data in my database ...
3
votes
1answer
1k views

query cache hit value is not changing in my database

The query cache hit value is not changing in my database only for some queries.If I write select * from drugs_info limit 1000; the query cache hit has changed, but if I execute the following ...
1
vote
1answer
463 views

Innodb issue is preventing MySQL from starting [closed]

For some reason mysqld refused to start after I rebooted my server. Now when I try to start it I will get the following error: [root@vps1 ~]# service mysqld restart ERROR! MySQL server PID file ...
0
votes
2answers
169 views

Do I need to reindex my table in mysql after delete?

I have a table in mysql with a lot of INSERT and SELECT at every second. And there is a bulk delete of some older data once in a day. Do I need to reindex the table after delete? I want to increase ...
1
vote
1answer
60 views

MySQL InnoDB + high table creation-destruction rate

We are transferring a microsoft SQL based website (+app + plugins) structure to MySQL. The website has a high "Content + Comments + Activity Tracking" behaviour. Mainly because of the activity ...
0
votes
1answer
1k views

ib_logfile0 and ib_logfile1 got deleted

After restoring from a percona-xtrabackup without a preparation step, ib_logfile0 and ib_logfile1 were not present in the restore data. Therefor during startup the following message is observed: ...
1
vote
0answers
43 views

Can't seem to optimize joined select query

Can't seem to figure this one out. Query is taking upwards of 7-8 seconds which is just not acceptable and seems as though it will get worse as the table(s) get larger. Without going into a ton of ...
0
votes
0answers
419 views

MySQL Inno DB Crash

This is the log of the crash. Basically every time I run a query it looses connection an crash. 2014-11-03 19:46:42 58021 [Note] Event Scheduler: Loaded 0 events 2014-11-03 19:46:42 58021 [Note] ...
0
votes
1answer
235 views

moving binary database folder is causing issues with innodb tables

so I have a mix of myisam and innodb tables on a database. (its a pretty big db 30gb) I copied the folder of the database from one server to the next /var/lib/mysql/databasename well the myisam tables ...
1
vote
1answer
3k views

How to recover the innodb when mysql data dir moved from one system to another system?

I have transfer the mysql data dir from one linux box to another box. When i start the mysql server. I can find that the innodb based DB are corrupted. So, may i know how to recover the corrupted ...
1
vote
1answer
395 views

Move a MySQL 5.5 database to a server running MySQL 5.1

I have a backup of a MySQL database (using InnoDB) from a Windows machine that was running MySQL 5.5. The Windows machine is no longer available and now I need to import the backup into an Ubuntu box ...
1
vote
1answer
47 views

Does InnoDB Log Files take RAM space or Disk Space

When I set InnoDB Log File size to 512M, does it take the space (512M * 2) from RAM or the SSD Disk space? When I explored, I can see that the log files are located inside /var/lib/mysql folder. So ...
0
votes
1answer
2k views

How to resolve “InnoDB data dictionary has tablespace id N” [duplicate]

I recently messsed up a migration to table-per-file for my dbs. In the end I (thought) I dropped all dbs, deleted any left over files, and then started over from scratch, importing only dbs I needed ...
-2
votes
1answer
92 views

How to efficiently model this simple data structure?

catId(INT) | userId(INT) | catName(VARCHAR) 0 1 Cat1 1 1 Cat2 2 2 U2Cat1 3 2 ...
1
vote
1answer
116 views

Immigrate to file-per-table mode in MySQL

I have 20 MySQL databases and in each there are about 20 tables. All the data is saved in a file called ibData1. Now I discovered about the file per table mode but if I change the value in the my.ini ...
0
votes
1answer
731 views

Best Innodb Buffer Pool Size for 8GB RAM?

I found out that my MySQL server is configured with only 128MB for innodb_buffer_pool_size. That is not enough considering that I have a 8GB RAM server. It hosts MySQL server and an Apache/Catalina ...
0
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0answers
734 views

Benchmarking MyISAM vs InnoDB using Sysbench on MariaDB-10.0.14

I performed a "read" benchmark on MariaDB-10.0.14 db server using sysbench to compare performance between InnoDB and MyISAM on a single. Below are the sysbench commands i used: Create test table in ...
3
votes
1answer
5k views

When are InnoDB table index statistics updated?

In a vanilla build of MySQL 5.5.20, when are InnoDB table index statistics updated? What events trigger such updates? I've seen comments suggesting that the following might trigger it: table is ...
0
votes
1answer
53 views

update column without auto timestamp update

Hello everyone I have got a product stock table with a time-stamp column so the so any updated to that row will update the time stamp ,I'm happy with this setting but sometimes I want to update the ...
2
votes
2answers
4k views

MySQL 5.1.63 - using tuning-primer - Table Cache question

tuning_primer says the following: TABLE CACHE Current table_open_cache = 812 tables Current table_definition_cache = 256 tables You have a total of 498 tables You have 812 open tables. Current ...
0
votes
1answer
287 views

MariaDB Galera setup with drastically different amounts of memory used on cluster nodes - why?

We have a 3 node MariaDB Galera cluster. All nodes are identical and the config on each is identical. They have 64GB of RAM each. The output of the following query is 28: SELECT ...
0
votes
1answer
642 views

Workaround to avoid read-only table locking during execution of MySql OPTIMIZE command

We need to optimize a large table (on a weekly basis) in order to reclaim disk space, since records are being deleted regularly from the table. The table in question is an InnoDB table and the ...
0
votes
0answers
317 views

Using partitioned table, and dealing with auto_increment PK

I have a big table (>100 million rows) that tracks user's activities. It has an ID, which is PK and has auto_increment property. This is the only unique key. Table also has userid and datetime column. ...
0
votes
1answer
45 views

InnoDB error: exceeded log capacity…but only during import

I see this error in mysql.log: InnoDb error: the age of last checkpoint is...which exceeds the log group capacity etc.. I think I understand it, but the fact is that it's happening only during a ...
1
vote
2answers
142 views

Fourth inner join to the same table increases query duration significantly

As soon as I add a fourth inner join to a specific table, the query duration increases significantly: sub 1sec to 45sec. The table in question is deployments d4. The SQL Query: select a.id as ...
0
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0answers
62 views

MySQL on Server side PRIMARY KEY taking automatically random Id

I have problem in my database which i have uploaded in Database Version libmysql 5.1.73 In that i got problem like one PRIMARY_KEY field incrementing random values. inserted id's like 1, 2, 35, 67, ...
0
votes
1answer
227 views

In which situations is TokuDB higher performance? [closed]

I noticed that WordPress runs quite a bit faster when I use XtraDB (MariaDB's InnoDB replacement) instead of TokuDB. This is strange, because TokuDB is advertised as being 20x faster. However, I ...
0
votes
3answers
814 views

Mysql Create table shows ERROR 1005 errno 150

I am trying to make a junction table, but I getting a ERROR 1005 errno 150 CREATE TABLE 61furiousFistPokemon( cardNumber int NOT NULL PRIMARY KEY, pokemonName VARCHAR(12), type VARCHAR(10), stage ...
3
votes
1answer
88 views

Super slow (day long) count(*) after upgrade to 5.6

After upgrading to Percona 5.6.20 from 5.5.34 I noticed counts on larger tables take a massively long time to execute. The table is about 27G and 300M rows. It is not compressed and was innodb ...
1
vote
0answers
129 views

MySQL keeps inserting new rows automatically [closed]

I have no clue of what is going on. My script goes this way: $i = 0; $c = $somecount; while($i < $c){ $en = comment_version($comments, $i, 'en'); $ru = comment_version($comments, $i, 'ru'); ...
0
votes
1answer
44 views

How to combine duplicate parent rows in a relational MySQL table

I have my DB structured like this with people.person_id as the foreign key for each row in people_meta. people table ╔═════╦════════╦═══════╗ ║ id ║ fname ║ lname ║ ╠═════╬════════╬═══════╣ ║ ...
0
votes
0answers
155 views

Very slow response even with a high number of available connections

I'm running this server for data mining purposes. It runs several compute-intensive data mining applications in parallel and does simultaneous access to the MySQL server. Here are the ...
1
vote
2answers
769 views

Very high load avg for MySQL database [closed]

I have a backend server which response to my clients app, it has more than 20k~25k hit per second and this make my server load average very high, I believe that my MySQL config is not appropriate. In ...
2
votes
2answers
303 views

Should we enable innodb_file_per_table for single tenant SaaS app (thousands of databases)

We have a mySQL backed SaaS application where each customer has their own mySQL database. So think of it like a wordpress/magento etc. database for each client. Each database has ~200 table, and we ...
1
vote
1answer
335 views

I broke replication. Could this have been fixed?

I ran mysql_upgrade on both my master and slave after upgrading to a later version of mysql. Somewhere during this process replication broke for the mysql table. I was able to fix it manually, but ...
3
votes
1answer
14k views

How can extract the table schema from just the .frm file?

I have extracted the data directory of mysql from a backup and need to get the schema from an old table, however it's a backup from a different machine. I have read a fair number of tutorials today ...
1
vote
1answer
791 views

How to take physical backup of MYSQL database

I am trying to find out some tool which can take physical backup of MYSQL database. Like mysqlbackup but it is not open source. There is mysqldump but i want to take physical backup. Can someone ...
0
votes
1answer
76 views

Identifying root cause of slow query outliers from pt-query-digest?

I've run pt-query-digest and noticed many outliers with very high query times. Many of these queries do not perform slowly when I run them myself, and I'm having trouble figuring out the root cause of ...
0
votes
2answers
233 views

MySQL thousands connections after convert MyISAM to InnoDB on fail-over structure

I've acquired a fail-over structure and I migrated my databases to new structure converting all tables of my database from MyISAM to InnoDB engine, but, after import all databases, I have a problem ...
3
votes
1answer
498 views

MySQL / Fusion IO Configuration Question

I need a little configuration optimization. I think what I have is pretty good but feel like there's still room for improvement. Current Config [mysqld] user=mysql datadir=/var/lib/mysql ...
1
vote
1answer
3k views

Shut Down MySQL during InnoDB rollback after crash

I am puzzled once again. We had a server crash last night during some huge queries. Upon restart in the morning MySQL went into recovery mode. I needed to shut down the MySQL service and it is ...