1
vote
1answer
28 views

MySQL repair deleted data - Any chance of recovery?

Well, this has been a long Saturday morning. MySQL was throwing an error when dumping backups. That error was... mysqldump: Error 1030: Got error 5 from storage engine when dumping table mytable at ...
0
votes
2answers
50 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 ...
1
vote
0answers
25 views

“Unexpected EOF” during SELECT on huge MyISAM table

When executing a SELECT query that uses filesort on a huge table (2 billion rows) the execution stops after ~30mins with the following error message: ERROR 9 (HY000) at line 1: Unexpected EOF found ...
1
vote
1answer
238 views

MySQL backing up MyISAM tables by copying the physical files - and automating the process

I have 2 databases with MyISAM tables running on a Windows 2008 Server. These databases are about 20GB in size with a few tables with millions of rows. My question regards backing them up on a weekly ...
1
vote
1answer
23 views

How do i increase the total MyISAM indexes?

I have just made a check for my server with mysqltuner. -------- Storage Engine Statistics ------------------------------------------- [--] Status: +Archive -BDB +Federated +InnoDB -ISAM -NDBCluster ...
1
vote
1answer
48 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 ...
1
vote
0answers
43 views

Indexed query fails to return rows in large (15 billion rows) MyISAM (MySQL) table

I have a very large table (15 billion rows) with a structure like this: CREATE TABLE `textlines` ( `PGUID` binary(16) DEFAULT NULL, `StatID` int(11) DEFAULT NULL, `Time` datetime(3) DEFAULT ...
3
votes
1answer
281 views

Is there any performance difference in using a unique index on primary key?

I know there are lost of similar questions to this one, but none that really answers this: Is there ANY difference in performance in using an unique index in a primary key, using a MyISAM table on a ...
10
votes
2answers
168 views

MySQL instance stalling “doing SYNC index”

Problem An instance of MySQL 5.6.20 running (mostly just) a database with InnoDB tables is exhibiting occasional stalls for all update operations for the duration of 1-4 minutes with all INSERT, ...
8
votes
2answers
269 views

Why are simple SELECTs on InnoDB 100x slower than on MyISAM?

I have quite an annoying problem. I want to use INNODB as my main database engine and give up on MyISAM as I need the former for using galera-cluster for redundancy. I copied (description follows) ...
4
votes
1answer
253 views

How to setup complex multi-column index for massive table

I've searched what I could search on Google, SO, etc and haven't found an answer that would seem to fit what I'm looking for. I'm hesitant to make a post about this as I'm sure the answer is out there ...
2
votes
1answer
346 views

What could cause waiting for table metadata lock?

I am using a MySQL 5.6 DB with MyISAM tables under FreeBSD 8.3. The main part of code is in PHP, but the problem arises, when I launch the self-written on C++ chat-server. I use the mysql.h for DB ...
0
votes
1answer
99 views

Why is my Mysql Query verry slow when selecting a text field

i have a problem with a left join. Tables are myisam. Tables CREATE TABLE `article` ( `id` bigint(20) NOT NULL AUTO_INCREMENT, `force_startpage` tinyint(1) DEFAULT '0', `title` varchar(255) ...
0
votes
2answers
62 views

Alter auto-increment of table with 16 million rows

Learned this the hard way. Need to alter a table's auto-increment with 16 million rows. Now, it's taking quite sometime. Any estimate how long it would take? Sorry.
0
votes
4answers
129 views

Converting to MyISAM, `foreign_key_checks = 0` Not Working

At the end of a long series of compromises working in a system I didn't design, own, or maintain, I need to convert a number of MySQL InnoDB tables to MyISAM tables. However, when I attempt to alter ...
0
votes
0answers
272 views

mysqlcheck --repair a specific table?

I logged in my server via SSH and committed a "repair table xxx" query on a MyISAM table with 34 million rows and 69GB of data. Unfortunately the SSH connection was lost. When I logged back in I found ...
1
vote
0answers
61 views

Question on MySQL insert race condition

I'm using MySQL 5.1, PHP 5.3 and the table is MyISAM. Here's the DTD of this very fake table: CREATE TABLE `temp1` ( `value` varchar(10) DEFAULT NULL ) ENGINE=MyISAM DEFAULT CHARSET=latin1 This ...
1
vote
1answer
45 views

MRG_MyISAM with myisampack tables blocking inserts

I'm using INSERT_METHOD=FIRST and compressing all tables that are members of the union but when I try to insert into the MRG_MyISAM table it tries to insert into the second one (instead of the first). ...
2
votes
2answers
72 views

Whats row size in mysql?

i mean what does it mean ?, i have mysql db and table in myisam and it shows Space usage Type Usage Data 1.3 GiB Index 429.1 MiB Total 1.7 GiB Row Statistics Statements Value ...
1
vote
1answer
83 views

Options to include with mysqldump when taking backup of hybrid databases

I'm planning on taking backups of all MySQL databases on a remote production server. The combined database size is around 2 GB. Most of the tables are InnoDB ~1.8 GB and the rest are MyISAM. Now I've ...
0
votes
1answer
75 views

How to transfer 70GB MySQL with no downtime?

I have a large amount (4000) of individual databases, 90% of which are small. They all include about 20 tables each, and in total, they use about 75GB of space. All tables are MyISAM. I want to ...
0
votes
0answers
23 views

How do I stop views (large data sets) from freezing my database

I am working with tables that contain upwards of 200,000 rows. My boss wants to use views that refer to other views in order to have things be more automated. The problem is that the MySQL server ...
0
votes
0answers
78 views

What is a good database design (schema) for an article search engine application?

I'm trying to make a article search engine application. There are about 1 million articles that will be stored in the DB. I've tried looking around for some similar examples, but I couldn't find any ...
0
votes
2answers
62 views

Should I create a multi-column UNIQUE index?

I have created the following MySQL table, which stores which sections of our site a user visited (and the Count of visits): CREATE TABLE `Visits` ( `ID` int(10) unsigned NOT NULL AUTO_INCREMENT, ...
0
votes
1answer
212 views

Queries are taking long time to execute

I have large DB around 25 GBs and the most busy table is around 9.5 GBs, database is increasing @ 10% per month, I am using mysql with MyISAM engine. Problem started 3 days back, there is long list ...
2
votes
1answer
98 views

mysql Wrong bytesec: 0-0-0 at linkstart: 0

I have several MySQL (MyISAM) tables that have been corrupted. Running CHECK TABLE mytable returns: > +-----------------+-------+----------+----------------------------------- | > ...
0
votes
1answer
344 views

How to configure my.cnf for Mysql 5.1, which is using too much CPU?

I am new Database engineer. I am having trouble in my server which is using too much CPU on database query(simple count statement). I have googled about it, so i found out it depends on system ...
0
votes
0answers
98 views

MySQL: after query optimization the CPU is still over 100%

my first time here! First of all I want to say that I'm not a DBA and I have a very little experience with MySQL but I like to study and understand what I'm doing. I have a virtual machine (2gb RAM, ...
1
vote
1answer
70 views

Concurrency Issues when multiple users uses Portal (MySQL and PHP)

We have set up a portal using Yii Framework in Apache, PHP and MySQL. In the portal, there is a feature to export the data in dbf format, the extract takes around 7 minutes, but in those 7 minutes no ...
0
votes
1answer
76 views

MyISAM : Should I be concerned by these warnings?

I restored some tables from recent Databases backups. Because Im supporting a legacy system that only uses MyISAM tables in their DBs, for backing up I used a little script that pretty much copies all ...
1
vote
1answer
102 views

Mysql sequential numbering based on MAX of another column

I've a table lp_pictures which have these fields: [id | plate_uid] [1 | aaa] [1 | aaa] [1 | aaa] [1 | bbb] [1 | bbb] [1 | bbb] and i need to UPDATE the field id to becomes: [id | plate_uid] ...
1
vote
0answers
193 views

How to generate data for News Feed efficiently like facebook , googleplus , twitter e.t.c?

I have created table as post ( post_id int(15) auto_increment primary key , user_id int(11) , post_text varchar(2000) , post_type int(1), ...
2
votes
1answer
157 views

MySQL Error 1114 “table is full” Using MyISAM Engine

When executing the following query, we run into the error The table '/var/lib/mysql/temp/#sql_2d22_1' is full (actual table name varies). I've done a fair amount of research on this; most of the ...
2
votes
1answer
312 views

Why would the size of MySQL MyISAM table indexes (aka MYI file) not match after mysqldump import?

I've been archiving some MySQL (version 5.0.96) MyISAM tables locally and deleting from my server after checking the data. Every time the process has been pretty similar and comes off mostly without a ...
8
votes
2answers
264 views

Why would MySQL do serial synchronous I/O?

When looking at a particularly annoying query over MyISAM tables which takes a long time to execute on a number of occasions, I have noted that MySQL seems to expose a rather strange I/O pattern: when ...
2
votes
1answer
140 views

Does MySQL guarantee atomic upgrade from read lock to write lock?

If a client session is currently holding a read lock (to allow concurrent reads while already preventing writes), and then acquires a write lock on the same table(s), does MySQL guarantee that the ...
1
vote
1answer
60 views

Migrating MyISAM tables from 5.5 => 5.6

I was wondering if anyone had any pointers on migrating MyIASM tables from mysql 5.5 to 5.6, specifically using Percona builds, via an rsync? Is this safe? I know we need to do a full ...
2
votes
1answer
477 views

Space not reclaimed after dropping MyISAM table

I just dropped a rather large MyISAM table (~4 gb); it was 350k rows with about 11k of data per row. However, when I run df -h on my database server, I am still at 100% disk usage, so much so that I ...
1
vote
2answers
199 views

Why is MySQL not using the index with the higher cardinality?

I have an index called source with cardinality of 1122 and a second index called state with cardinality of 22. MySQL keeps using the state index when when query SELECT C1 FROM tbl WHERE source = 'x' ...
1
vote
3answers
377 views

Why does MySQL slow down in loading data?

We have a really large file (26GB) that we need to upload to MySQL. In order to do so we split it into nine 3GB files. What's confusing is that the first file took only 2 minutes to load, whereas the ...
0
votes
0answers
252 views

using Aria vs InnoDB vs MyISAM

I was wondering (if anyone knows) if Aria database is crash safe . I had some tables with MyISAM which were getting corrupted very often and switch them to InnoDB . However innodb is a bit slower and ...
1
vote
1answer
162 views

MySQL - Best long read query solution within a replication based system

I'm working on a project where work in a queue requires a database read against heterogeneous table schemas (InnoDB/MyISAM). The queries constructed during the "read" process can result in 10-15 ...
1
vote
1answer
55 views

MyISAM recover updated row

The row (with type MEDIUMTEXT) has been accidentally updated with empty value. I can see previous data in MYD file of a table, but I can't get them neither from mysqldump or any mysql client. If I ...
0
votes
2answers
54 views

MySQL query optimization for legacy application

I'm working with a legacy application that started out with little data years ago (developed by a third party custom for this client), and now we're seeing MySQL load skyrocket on this query alone. ...
0
votes
1answer
54 views

Fetching User Recent Status

I am running mysql with MyISAM storage engine to store user status(user updates data). To load user recent updates data i am using this query: $limit = 20; $uid = 3; SELECT * FROM userstatus WHERE ...
0
votes
0answers
42 views

Quick MySQL Backup (1 file per table) - v2

Improving bash shell script written by RolandoMySQLDBA. Continuing the following thread: Quick MySQL Backup (1 file per table) I tried to adapt your script, but after the first rsync was done, I get ...
3
votes
2answers
644 views

Does a MyISAM table locks if I copy it while MySQL is running? (READ DISCLAIMER)

DISCLAIMER: I'm very aware this is not supposed to be done, but time consistency between tables aren't a concert here and Im trying whatever pops in my mind right now to have alternatives for ...
1
vote
0answers
1k views

MySQL - high CPU usage (MyISAM tables)

We have a server running LAMP stack on CentOS release 5.6 (Final) MySQL is having high CPU usage constantly which causes server to lag as shown top - 13:50:47 up 80 days, 13:53, 1 user, load ...
1
vote
1answer
719 views

mysqldump: Does --lock-tables=false work with MyISAM tables?

So, I have to check and come with a backup solution for a very busy mysql server (with tables over 5 GB). Due to resources constraints, they choose to set all tables with the MyISAM engine. Currently, ...
0
votes
1answer
146 views

Best way to add a new column to a large table? (MySQL - MyISAM)

Here's more info on the table that needs to be altered: 15GB size MyISAM table with Index around 5GB Over 100 million rows MySQL 5.1 on RHEL 5 with 4GB RAM Currently live online What's the best ...