Tagged Questions

InnoDB : MySQL's ACID-compliant Storage Engine

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1answer
9 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 ...
2
votes
1answer
13 views

MySQL table indexes change location

Is it possible to move the MySQL Table indexes to another location rather than "datadir" ? for example a ssd drive or memory partition ?
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1answer
25 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 ...
1
vote
1answer
10 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? ...
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0answers
22 views

MySQL 5.6.19a InnoDB Concurrent Insert

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
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0answers
21 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 ...
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0answers
18 views

Statements in State “Copying to tmp table” disrupt performance

On a MySQL database (version 5.1.73) a Magento-Shop executes a statement (A) that uses distinct, see http://pastebin.com/A2sy45nF and therefore is "Using temporary" according to "explain". ...
2
votes
1answer
20 views

How to batch multiple insert statements for database dump with MySQL?

I have a MySQL database with some large tables. In particular, the largest table (by far) currently has ~11,000,000 rows. According to the a query I ran, the table clocks in at around 1.7GB, but it's ...
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0answers
20 views

Advice on table structure change

I am in the process of converting an Access application that stores and reports evaluations to being web-based using php and mysql. I have converted the structure and data over from Access and I have ...
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0answers
26 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 ...
2
votes
1answer
41 views

How mysql (innodb) handles auto increment column

I am working on a OLTP environment with multiple parallel write operation. I found this in documentation about auto increment locking but still i am interested to know much about it in details. Can ...
0
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2answers
38 views

Do I need to reindex mysql table after bulk 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 ...
0
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2answers
48 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
31 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 ...
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0answers
20 views

mysql uses a lot of virtual memory

I've a mysql server with a lot of small size innodb databases (each db also contains a lot of small tables) & 6GB of RAM dedicated to mysql server. Recently I've increased my ...
1
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0answers
39 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
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1answer
20 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 ...
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0answers
31 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] ...
1
vote
1answer
18 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 ...
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0answers
19 views

MySQL Crash due to “InnoDB Assertion” after Query

Current setup: Ubuntu 12.04 LTS MySQL 5.5.31 Current Use: Slave - Only ETL queries 64 GB RAM Intel(R) Xeon(R) CPU X5670 @ 2.93GHz - 12 Cores - Hyperthreaded (24 Logical) MySQL Main Settings: ...
1
vote
1answer
26 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 ...
0
votes
1answer
24 views

Query perfomance with multiple JOINs on MyISAM-based DB

I'm working with Enron Email Dataset in MySQL database. After I executed data import from dump-file into MyISAM-based DB, I got the set of tables without any connections between them via foreign keys. ...
0
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1answer
21 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 ...
0
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1answer
96 views

Hyperthreading & MySQL InnoDB Thread Concurrency Performance

I have a dedicated DB Server with the following specs" Ubuntu 12.04 LTS Server Intel(R) Xeon(R) CPU X5670 @ 2.93GHz 12 Cores MySQL 5.5.29 64 GB RAM RAID10 We are currently doing Hyperthreading ...
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0answers
30 views

MySQL - Pending flush list, aio write, and the innodb_use_native_aio parameter

I'm running an Amazon RDS instance with MySQL 5.5. The applications using that are very write intensive, and there's over 1TB of data. Everything was fine until a recent minor version upgrade and ...
0
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1answer
49 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 ...
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0answers
65 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 ...
0
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1answer
25 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 ...
0
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1answer
45 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
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0answers
16 views

How to diagnose MariaDB crash when changing InnoDB column to AUTO_INCREMENT?

I have this table, and I'm trying to change the first column to AUTO_INCREMENT: +------------+---------------------+------+-----+---------+-------+ | Field | Type | Null | Key | ...
0
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0answers
24 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
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0answers
17 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
37 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
1answer
24 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 ...
0
votes
1answer
25 views

mysql autoincrement counter

I need a way to keep auto-increment counter between mysql service restart. As docs states by default after restart mysql autoincrement counter start from max(id)+1. How can I keep the last ...
1
vote
0answers
43 views

innodb slower much slower than expected

Trying to figure this one out and I apologize for not providing a lot of information from the start (if you need further let me know and I can try to provide it). Query is performing very poorly - it ...
1
vote
2answers
72 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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3answers
33 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 ...
2
votes
1answer
58 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 ...
0
votes
1answer
20 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 ║ ╠═════╬════════╬═══════╣ ║ ...
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0answers
58 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
2answers
96 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 ...
1
vote
1answer
47 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 ...
1
vote
1answer
44 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
26 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
1answer
38 views

Sudden periods of performance degradation

For the past couple of days, Ive been observing periods of huge performance degradation. CPU usage on our master MySQL server (Percona Server (GPL), Release rel24.1, Revision 217, InnoDB version ...
1
vote
1answer
110 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 ...
0
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0answers
34 views

innodb fulltext Table handler out of memory

I am running mariadb 10 and have a large innodb table with a fulltext index. When searching I am regularly getting this error ERROR 128 (HY000): Table handler out of memory Is there some way I ...
0
votes
2answers
62 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 ...
0
votes
1answer
35 views

Joining a column from another table with InnoDB engine

I'm using MySQL with InnoDB and I want to join the location column from products table into a productStock table. I have this table 'products' mysql> select * from products; ...