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.

learn more… | top users | synonyms

1
vote
0answers
87 views

Mysql Replication Master/Slave and Master/Master

Looking for some insight and opinions from some DBAs, as I've been tasked to look into using Master/Master replication for a single table in a database. We currently run mysql replication using a ...
0
votes
1answer
44 views

How to restart mysql slave node?

i have 8 slave servers and i need to restart one of them but in my.cnf file master-host, master-user etc. variables dont exists. So if i restart server as indicated here replication will start again?
2
votes
1answer
360 views

How big can innodb_doublewrite_file grow?

When I use the enable innodb_doublewrite_file ... How big can this file grow ? How can I calculate the optimal disk size, if it would be used only for this file?
0
votes
1answer
2k views

mysql view with user variables

I have a query that calculate distance from point a to point b using gps coordinates, and would like to make it view. Is it posible to pass variables that will replace xxx and yyy in my query with ...
0
votes
1answer
243 views

What is the best partition technique for large table with TEXT column?

MySQL: What is the best partition technique for large InnoDB table (around 1.5M rows) with TEXT type of column? There is a FULLTEXT index on the TEXT column, which is very essential for my searching ...
0
votes
1answer
331 views

What will be the best mysql configuration for 12 core processor 128 gb ram ssd 160gb hdd

What will be the best mysql configuration for 12 core processor, 128 GB ram sized 160gb HDD. Mysqltuner.pl result! -------- General Statistics -------------------------------------------------- [--] ...
2
votes
0answers
76 views

Count how many locks required for a MySQL (InnoDB) query

I'm performance tuning a very data-heavy mysql application. It has a purge system that often seems to cause lock timeout errors for users. Based on my research I have a few adjustments to the query to ...
0
votes
1answer
88 views

How do I reduce time spent “preparing”? [closed]

I have a query I need to make more efficient. Trying a couple different things, one of which is SHOW PROFILE . That shows that the most massive timesink by far is "preparing". As far as I understand, ...
0
votes
1answer
63 views

MySQL: join query

I've got the following two tables: mysql> DESC domains; +-----------------+--------------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra ...
0
votes
2answers
104 views

Table Design Cardinality

I am designing a database for an application, in that I need to consider both BUYER (BUYER_ID) and VENDOR (VENDOR_ID) as a USER (USER_ID). I have designed this logic in a following design. USER ...
1
vote
1answer
34 views

Request shown in slow logs

In my MYSQL configuration I activated logging of request not using indexes. slow_query_log=1 slow_query_log_file = /home/mysql/sqlprive.log long_query_time=7 log_queries_not_using_indexes =1 But ...
1
vote
1answer
505 views

Native replication from Percona XtraDB Cluster to a standard stand-alone slave

I'm replicating from one node of a three-member Percona XtraDB cluster to a separate slave, using regular MySQL replication. The node is set to write binlog in ROW mode, with log_slave_updates=true ...
3
votes
1answer
396 views

restrict user host settings to socket connection only

Is there a way to restrict a user's host setting so that (s)he can only connect by socket and not TCP/IP? I'd like to have this setting for the root account. edit: As Abdul Manaf pointed out ...
0
votes
2answers
439 views

Help my database isn't performing fast enough! 100M Merge with 6M need < 1 hour!

I have a server right now receiving more raw data files in 1 hour then I can upsert (insert -> merge) in an hour. I have a table with 100M (rounded up) rows. Table is currently MyISAM. The table has ...
2
votes
1answer
574 views

Optimize table and query, aggregate by date or date-hour

I have a table storing sensor data (100M rows currently) from stations from different sites. In my case, sites may have many stations. Create table statement is as follows: CREATE TABLE sensor_data ( ...
3
votes
2answers
8k views

Synchronizing data between MySQL and Oracle databases? [closed]

I want to sync data between Oracle & MySQL databases. What is the best possible way to achieve this? Are there any tools/software available? This is not a one-time but an ongoing operation. The ...
0
votes
1answer
229 views

How to model complex database role relationships

The purpose of my application is the creation, viewing and editing of articles. The problem I have is that users will have different roles for an article or group of articles. In addition, the role ...
0
votes
1answer
517 views

MySQL: Procedure for mysql certification

I have keen interest in database and since start of my career I worked only in MySQL. But, I have not any professional certification related with MySQL. I have below concerns for certification: Any ...
0
votes
1answer
828 views

MySQL crashes daily on VPS with Ubuntu Server 12.04 - How can I find the error or conflict?

Every day for the past four days, my website server crashes at least once. (Error establishing database connection. As long as I catch it, I simply have to do the following command: sudo ...
0
votes
2answers
2k views

What is the last Mysql Version supported in REDHAT 6?

Maybe not such a good question ! But my Linux admin is to busy to answer my doubts. SO: I have all my Mysql servers running on 5.1.69 version(the free one) that comes with RedHat O.S. My users are ...
0
votes
0answers
47 views

What Index can I apply to a GROUP BY, MIN() and WHERE MySQL Query

I have the following table: CREATE TABLE `wp_prize_draws_log_copy` ( `id` int(11) unsigned NOT NULL AUTO_INCREMENT, `pid` int(11) NOT NULL, `entry_date` date NOT NULL, `entry_time` datetime ...
1
vote
1answer
4k views

Using count in triggers to update another table

Say i have a table called trx_request with the following data id | confirmed(TIME) | finished(TIME) ------------------------------------- 1 | 12:05:00 | NULL 2 | 13:11:00 | NULL and ...
1
vote
2answers
441 views

Copy On Write Transparent database for MySQL

It is possible to create a transparent database to another production database server? I mean, testing new functions in a production database is too dangerous. What if we create a database which based ...
1
vote
0answers
461 views

MySQL Space efficient way of storing indexed key-value pairs associated with table

We're storing transactions in an accounting system using two tables, one contains the general description of the particular transaction (the other contains the entries, one for each account - which ...
1
vote
1answer
80 views

Counting number of visitors who did NOT log in

I'm trying to calculate the number of visitors to the homepage of my site who did NOT then log in to the member's section of the site, while also filtering bots and admin users. Bots and admins are ...
12
votes
2answers
6k views

Reasons for occasionally slow queries?

We are running MySQL 5.1 on Windows Server 2008 R2. We have been doing some diagnostics on our database of late and have found some disturbing artifacts which we can't explain. We added some code to ...
1
vote
0answers
234 views

MySQL aggregation count performance

I have a table with about 30 million records, and I'm doing a query where I can group by field Year and count the results for that year. The table structure looks like: id | year | amount The ...
1
vote
2answers
540 views

Generic SQL Job Scheduler for multiple RDBMS's?

I have been searching for an answer to this, but can't seem to find anything. So my problem is this - we have an environment with MS SQL Server 2008, MySQL, and RedShift, and have some complex ...
0
votes
1answer
197 views

What is the most efficient way to update a product table with 1 million rows in MySQL

I need to update a product table which currently has 1 million rows. For each row, I need to perform an expensive http operation and then update 1 field in the row based on a returned header. I've ...
3
votes
1answer
4k views

Mysql error 28 no space left on the device

I keep running in to the same problem with mysql with error code 28 which means there is not enough space left on the device. Now the weird part is that there is enough space, here are some tips i ...
3
votes
3answers
1k views

MySQL Tables Require Daily Repairs - Server, Table or HD?

I've been experiencing a weird issue with one of MySQL DBs. Every day, sometimes 2-3 times per day, I'll need to repair the tables. The MySQL DB has 25 tables with 5.6m rows in total. The bigger ones ...
-1
votes
1answer
462 views

Error in upgrade_from_array - mysql: 1064 query: DROP TABLE IF EXISTS filling tables

Error in upgrade_from_array - mysql: 1064 You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'myhandyrestaurant' ...
2
votes
2answers
3k views

Is it possible to index a computed column used in ORDER BY?

I am having problems with my mysql server, because of not properly written queries. I did not use indexes, because I do not know how to add them on computed columns, in a query that has SELECT ...
0
votes
1answer
2k views

Mysql update table using ubuntu terminal

I have a CSV file that has 2 columns Name Email I have a table in my database that has the same columns + some extra columns. Now I would like to update my db table using that csv file. I mean ...
1
vote
1answer
80 views

Delete in big table data all data, where foreign_id in other table didn't exist [closed]

Let's say i have two tables: table_a: id | article_id | text article: id | text table_a for example contain data: 1 1 "" 2 1 "" 3 1 "" 4 2 "" 5 3 "" and table articles such ...
1
vote
2answers
2k views

Trouble with triggers and insert .. on duplicate key update

I have two tables with identical schemas. one is a "main" table that is pruned periodically and kept small. The other is a "reporting" table that is an archive of everything that ever was. For ...
0
votes
1answer
2k views

Recover an Innodb mysql database from an EBS on Ec2

My instance crashed on AWs, and i had to create a new one and mount my Vol that contain my web application and the Mysql Database. After i stoped the Mysql Server i mounted the vol and also mounted ...
7
votes
3answers
2k views

Appropriate multi-language schema, or overkill?

UPDATE 2: I've actually ended up using this, and it's great after a couple tweaks. Here's my post on its actual design, and in action: http://tim.hithlonde.com/2013/lemon-schema-works/ I am building ...
0
votes
0answers
565 views

ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: NO)

Im trying to to dump an old database system to migrate the data. # mysql --version mysql Ver 14.12 Distrib 5.0.32, for pc-linux-gnu (i486) using readline 5.2 The weird part is this: # mysql -u ...
0
votes
1answer
60 views

Why is the index not used?

When I run the following querys in MySQL: SELECT count(*) FROM Inventory AS i WHERE i.lastModified > 1389920146804 or SELECT i._id FROM Inventory AS i WHERE i.lastModified > 1389920146804; ...
0
votes
1answer
1k views

row-based replication with slave triggers

I'm replicating a prod MySQL database to an analytics one. I need to drop several tables with sensitive data from the analytics and also redact several columns of several remaining tables, replacing ...
3
votes
2answers
588 views

PHPMyAdmin for multiple servers w/ single pma database

We have PHPMyAdmin setup for our various MySQL instances. The annoying part is the current setup is requiring an individual pma database on each instance. Because of this the severs that are slaves ...
0
votes
1answer
35 views

How can I set a field when original lookup is NULL or isn't in the list?

I am trying to merge our HR data. I had to create my own tables to give a "regions" table DROP TABLE IF EXISTS testgiver.ldap_karen; CREATE TABLE testgiver.ldap_karen (uid VARCHAR (10) NOT NULL ...
3
votes
1answer
2k views

How to determine MySQL queries per day?

I'm investigating the big switch from MySQL to a NoSQL DBaaS and I've run into an issue trying to forecast expenses. Essentially, I can't figure out how many queries my current MySQL server handles ...
0
votes
1answer
855 views

MySQL: What is SQL mode and why we use it

If in an application, if we execute sql_mode=mysql4.0 as a first query in my application but using MySQL 5.1 in my application then what will happen? Will my system use MySQL 4.0 or MySQL 5.1 ...
1
vote
2answers
397 views

Why does MySQL + Windows Server = crashed tables periodically?

Windows Server 2008 R2 x64 MySQL Server 5.6.14 x64 Is anyone else having an issue in where some tables are marked as crashed on a Microsoft Windows server? We have a couple of Windows servers (not by ...
0
votes
1answer
54 views

Order result by number of occurence of a word in a text

I am working with sqlite3/python . I would like to order results by the number of occurence of %@% in text. For exemple Jimmy 10 // Jimmy wrote 10 strings like %@% James 2 Sophia 0 ..etc The ...
1
vote
1answer
267 views

How to calculate average of list of qualifications of each pupil MYSQL

I have this database and query: http://sqlfiddle.com/#!2/b4cf72/116 And I would like to add a column with the average of the exam qualifications. However, I try doing this but it tells me there are ...
4
votes
2answers
5k views

Error Querying MySQL server linked to SQL Server 2008

I've created a linked server in MS SQL Server 2008 to a remote MySQL server. When I try to query any tables, I get an error: .tablename. contains no columns that can be selected or the current user ...
15
votes
4answers
3k views

How to create a conditional index on MySQL?

How to create an index to filter a specific range? AFAIK it's impossible to create directly but I think it's possible simulate this feature. Example: I wanna create an index for NAME column just to ...