All versions of MySQL (not Microsoft SQL Server). Please also add a version-specific tag like mysql-5.7 if that is relevant to the question.

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2
votes
2answers
228 views

Do Inactive MySQL Databases Consume Memory?

I have inactive databases that are on the server just for archive purposes. I know I can do mysqldump for all of them, but I am not 100% sure they are inactive. When I started my system I didn't ...
5
votes
2answers
7k views

ERROR - Function 'innodb' already exists

I'm looking to start converting some MyISAM tables to INNODB. Running Ubuntu 14.04 Server with MySQL 5.6 ( apt-get upgraded from 5.5 ), 32G ram on 4 core/ 8 thread cpu. Initially had trouble with... ...
0
votes
0answers
77 views

Mysql, performance problems with big database

I am running on Windows 7 64 bit with 4 GB RAM (used for Drupal based website). I have database dump of about 1.5 GB. After re-installing my XAMPP server, my MySQL server began working too slow. I ...
1
vote
0answers
161 views

Significant difference between duration for querys in SHOW PROFILE and SHOW PROFILES?

I have use mysql profiler to optimize an opencart query which takes more than 10 seconds to executes. mysql> SHOW PROFILES; ...
1
vote
1answer
2k views

update an id to max+1 in current table? (MySQL)

I've got a 'jobs' table where each row has a 'worker_id' that is either zero (job is not being worked on) or some unique ID that needs to be incremental. Basically, when assigning this worker_id, I ...
0
votes
0answers
1k views

Why is InnoDB waiting for table metadata lock in simple INSERT/DELETE + SELECT?

I've started using a new MySQL server and moved an InnoDB table there. I'm seeing a weird behavior that when I have a long running INSERT / DELETE, any SELECT from the same table is locked which is ...
2
votes
3answers
1k views

Whats the difference between information_schema.user_privileges and mysql.user?

I have the notion that privileges set in mysql.user should reflect in information_schema.user_privileges but when I try to alter some privileges in mysql.user and queried ...
3
votes
2answers
128 views

SQL Question: Selecting different language versions based on availability

I have the following situation: I have a table that contains entries with language versions (German and English) as part of the key (the other part being a "name" field). However, not always both ...
2
votes
1answer
12k views

Why does mysql adds a default timestamp on insert/update even if I did not specify anything?

I have a table that is as follows: CREATE TABLE SomeTable ( id int unsigned NOT NULL AUTO_INCREMENT, status enum('broken','repaired') NOT NULL, from datetime NOT NULL, until ...
0
votes
0answers
35 views

Analize Query in MySQL Server 5.1

I try use MySQL Workbench 6 to analyze the cost, but they don't show the cost of query. How i get this costs?
2
votes
1answer
246 views

Why does IN (subquery) perform bad when = (subquery) is blazing fast?

Have a look at these two queries: Simple: mysql> SELECT * FROM omgbatch JOIN omgoutput ON (idomgbatch=omgbatch) WHERE idomgoutput = (SELECT DISTINCT lastoutput FROM omgenvelope WHERE ...
9
votes
3answers
15k views

How do you re-sync the Master MySQL DB with Slave DB changes if the Master goes offline?

MySQL Server 1 is running as Master. MySQL Server 2 is running as Slave. With both DBs online, they are in "perfect sync". If Slave goes offline, there's no problem if Master still online; they will ...
1
vote
1answer
161 views

Syncing updates to master in master/slave setup [semi-sync replication]

Background info I have two MySQL 5.5 servers set up in a Master/Slave configuration with Semi-synchronous replication. The database is being used for a high-profile WordPress site. Problem It ...
2
votes
1answer
714 views

MySQL Seconds behind Master fluctuation

I have two servers set up in Master-Master with one additional Slave connected to the first master. Lately I've started getting alerts from monyog that Master 1 has a seconds_behind_master value of ...
1
vote
1answer
208 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] ...
3
votes
2answers
13k views

Execution of a Java program by a trigger.

I want to make an update trigger execute a Java program. I have a table T1 with a column named Flag. Whenever Flag changes, I want to run a trigger that results in an execution of a Java program. ...
2
votes
1answer
52 views

Will composite indexes or unique indexes help with query performance?

I need help with identifying indexes to increase performance of the following query. I'm currently using v5.5 with InnoDB. I cannot modify the query. However, I can add indexes as needed. The ...
0
votes
0answers
37 views

Optimise complex query

The previous developer has left an utter query inside our Joomla to search for companies or whatever that has somewhere the keyword. Here is the query SELECT DISTINCT con.id, con.title FROM ...
0
votes
1answer
504 views

desing the database for survey app with various types of answers

I have to create a survey app for which answers should be stored in the database. I created an html form containing some questions (about 30) with various types of answers (check boxes, radio buttons, ...
1
vote
0answers
711 views

MySQL dump error (#1005 - Can't create table 'novephp_cz_bv.jos_jquarks_customsets' (errno: 150))

I´m trying dump mysql database from MySQL 5.1. to MySQL 5.5. But I´m getting an error "#1005 - Can't create table 'novephp_cz_bv.jos_jquarks_customsets' (errno: 150)". Problematic part of script is ...
1
vote
1answer
2k views

Error #1093 you-cant-specify-target-table-table-name-for-update-in-from-clause

I'm trying the following sql code: UPDATE ticketsorders SET amount = $val WHERE id = $ticketsorder->id AND ((SELECT COALESCE(SUM(amount), 0) FROM ticketsorders WHERE ...
1
vote
1answer
2k views

Which is better MAX function or ORDER BY column_name DESC with LIMIT 1

I have one scenario where I want to have max value on date column, eg. for table CREATE TABLE IF NOT EXISTS `sample_table` ( `id` TINYINT UNSIGNED NOTNULL, `name` VARCHAR(45) NOT NULL, ...
2
votes
1answer
409 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
181 views

MySQL cluster concurrency

I have a little application that executes select queries against a MySQL cluster. By using 1 thread to read a record the latency is x. By using 2 threads to read records concurrently the avg latency ...
0
votes
0answers
86 views

Very slow inner join

newby on mysql so help needed I created a my sql query, on their own they run fast but when I enter the inner join it runs forever. i did index theres id tables but no result in speed. here is my ...
2
votes
1answer
2k views

InnoDB Buffer Pool Hit Rate

As given at http://cherry.world.edoors.com/COBFKUqnUdBY one can obtain buffer hit ratio by following sql query: SELECT round ((P2.variable_value / P1.variable_value),4), P2.variable_value, ...
0
votes
1answer
192 views

Create previously created MySQL database without .sql file

I had a bad server crash in which I was able to restore my MySQL files, but I was unable to do a dump in order to get the .sql file. In other words, I have each individual part that was saved in the ...
0
votes
1answer
47 views

how to speed up cpu limited mysql database backup

I have a database that has a structure that unfortunately requires having a lot of tables (10k+). It's not possible to change the structure now. The database itself is not very large (<1GB), but ...
0
votes
2answers
72 views

Why search by date field requires engine to touch all records?

Why search by date field requires engine to touch all records? Is there any way to avoid it? Following query EXPLAIN select * FROM playdays where realdate>=Date('2010,01,01') ; shows that ...
0
votes
1answer
4k views

Error “#1118 - row size too large” on the first row of the table only

I ran into a problem using a mySQL database. I have some columns as type text but when I try to enter data into the first row I get the error code "#1118 - Row size too large. The maximum row size for ...
1
vote
0answers
49 views

Getting upcoming world wide releases from a database

From my database I want to get upcoming world wide release dates for an itemId along with the platformIds. If I have a table that looks like this and the current date is 2014-05-14 ...
0
votes
1answer
334 views

How do you hide tool tips in MySQL Workbench?

Is there a way to hide the tool tips that popup when you hover over objects? Especially when you hover over tables, I do not want to see the breakdown of what objects are in that table.
1
vote
1answer
5k views

The InnoDB log sequence number is in the future

Our site was getting intermittent database errors and I asked my webhost to check what's happening. After some inspection they found that the database has few issues and tried repairing it. Finally I ...
4
votes
2answers
868 views

Wildcard for table permissions

I want to grant a user permission to select,insert,update,delete on a few tables in the prod database. However, I find it time consuming to write each grant statement out per table. Is it possible to ...
8
votes
4answers
8k views

No NULLs, yet invalid byte sequence for encoding “UTF8”: 0x00

I've spent the last 8 hours trying to import the output of 'mysqldump --compatible=postgresql' into PostgreSQL 8.4.9, and I've read at least 20 different threads here and elesewhere already about this ...
0
votes
1answer
912 views

Get the value of one attribute from the reference key of another table?

I have two tables named as ps_order_detail and ps_product_lang in MySQL. I want to get the product name from one table whose reference key is in another table. I have two tables. First the ...
10
votes
3answers
23k views

Modify DEFINER on Many Views

I have am having problems backing up my databases after an update. I have been poking around on my system trying to figure out why. One query I ran returned this result. Got error: 1449: The user ...
0
votes
0answers
34 views

How can I determine the performance (rows/second) for a certain query on one of my tables?

I want to find the performance (rows/second) for an UPDATE query on one of my tables so I can adjust my WHERE clause to select an appropriate number of records. The table has around 10 million rows. ...
3
votes
1answer
654 views

LOAD DATA stuck at Null State MySQL

I'm stuck trying to move one table to another, due to columns now no longer having proper references/meaning to their column titles. In doing this, I've created a new table with the same number of ...
1
vote
1answer
565 views

How to recover from two queries stuck in kill state causing all the database to not respond? [closed]

During a INSERT INTO new_table (f1, f2, ..., fn) (SELECT f1, f2, ..., fn FROM table) I clicked the new_table in php-myadmin which ran a simple SELECT * FROM new_table LIMIT 0, 30 which ofcourse ...
0
votes
0answers
27 views

loading k:v pairs from DB into JS Object

I'm creating a single player web RPG. I'm debating the following method of storing/retrieving quest items per player id: In userstats table, have a quest_items column of type mediumtext, where I ...
0
votes
1answer
97 views

Why use foreign keys if cascade action is not need?

I'm testing some queries with MySQL and tried to create two tables were there should be a reference between IDs. Something like: CREATE TABLE user ( id int(11) UNSIGNED AUTO_INCREMENT, name ...
0
votes
0answers
513 views

group by and order by making query very slow in mysql?

Query works fast: select SQL_NO_CACHE users.id, users.name from useres left join user_statistics on users.id = user_statistics.user_id where users.is_deleted = 0 group by users.id ...
1
vote
1answer
527 views

type recognition with MonetDB, *create* tables from CSVs

I am confused whether you can copy records into a new table in MonetDB. The official documentation seems to talk only about copying into existing tables. I have quite a large universe of billions of ...
3
votes
1answer
83 views

“zip” a mySQL (phpMyAdmin) database [duplicate]

I've created a large database on my local WAMP webserver. I would like to send that database with all tables and table data to another computer. Is this possible? mySQL ver: 5.5.15 PHP ver: ...
0
votes
1answer
478 views

Query with INNER JOIN takes long time than expected?

I have the following query, which takes longer than expected. Anybody help me find a faster alternative? SET SESSION MAX_JOIN_SIZE=18446744073709551615; SELECT claims.claim_id, ...
0
votes
4answers
186 views

Move MySQL database to another server

I need to move 20 Gb MySQL database from on Debian server to another. The problem is that there is no way to create its backup since there are almost no free HDD space on the source server. What would ...
0
votes
1answer
555 views

trouble installing percona 5.6 on google compute engine debian

I've been trying to install percona server on a fresh google compute engine instance. I havent installed mysql server previously. i followed the instructions from here ...
0
votes
2answers
94 views

Add column on huge InnoDB table in MySQL 4.1

I need to add a column on a huge InnoDB table (200GB) which resides on MySQL 4.1.21 (SunOS). CPU has 16GB RAM and 200GB of more disk space. Is there any quick way of adding this rather than ALTER ...
1
vote
0answers
113 views

MySQL: Slow Update Queries

Our database server hangs for exactly 30 seconds on random UPDATE queries. It doesn't matter what field type the query is updating, it just seems like random selection. There are a few applications ...