MySQL : Open-Source, Relational Database Management System

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2
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1answer
472 views

datetime vs timestamp in mysql 5.5

What is the difference between datetime and timestamp in MySQL with respect to data being inserted from different timezones? Does anyone have any clues on this? I have a situation where I am trying ...
0
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2answers
203 views

Using a keywords table with multiple other tables

Using MySQL I need help determining how to model a Keywords table to three different tables (Products, Certifications, and Exams) - I have included my model which is using what I refer to as ...
0
votes
1answer
128 views

Two identical MySQL tables, one not using indexes

I have one MySQL Server (5.0.37) on a Linux Server that have many databases. Some of them (12) have each an identical table to log sensors data. Schema of one table CREATE TABLE `measuresHistory` ( ...
2
votes
1answer
4k views

mysqldump: Got error: 1017: Can't find file: 'drupal_install_test' (errno: 2) when using LOCK TABLES

I'm trying to backup a drupal site database but I'm having some issues. When I ran the following command: mysqldump -uroot -p drupaSite > drupaSite.sql I get the following error: mysqldump: Got ...
4
votes
1answer
4k views

Reloading MySQL my.cnf changes

Do you have to restart MySQL to edit changes? Or can you edit them on the fly and restart MySQL or make the changes inside MySQL? This server runs 100s of website that are active and I don't really ...
2
votes
1answer
484 views

Repair with 1 thread

Why would MySQL be using Repair with 1 thread to rebuild the indexes on a table (1 primary key, 2 billion rows) when I have myisam_repair_threads set to 4?
2
votes
1answer
2k views

Dealing with empty strings while loading a table from a CSV

I am trying to load a CSV file into a table. The CSV file contains some empty strings for example: 1,2,,4 I want to load the empty field as null. One way I know is to use \N i.e: 1,2,\N,4 but it ...
1
vote
2answers
710 views

Is it okay to rename the MySQL data files (FRM) manually?

Like everyone, I realized the case sensitivity issues in MySQL of late. I wanted to convert my upper case table names to lower case using this solution but I forgot to do Step 1 and completed the ...
2
votes
2answers
469 views

MySQL Data Synchronization

I have a user who will be away from the office for a while, but still wants to be able to insert a load of records to our MySQL database. The user will have a laptop, but no reliable internet ...
2
votes
1answer
2k views

Ubnutu/MySQL - Error “Unable to locate package innotop”

I am using Ubuntu 12.04.2 LTS, with MySQL 5.5.29. Im trying to install innotop for database monitoring, but getting an error "Unable to locate package innotop" root@server1:~# apt-get install ...
1
vote
1answer
315 views

Drop database locked the server

I tried to drop one of the databases on the server. That locked the entire server up so I stopped the mysql process via the console. I restarted the server, started mysql and now it seems hanged on: ...
1
vote
1answer
1k views

SQL Server-MySQL master-master replication

We are looking into setting up a master-master replicated MSSQL database and I am interested to hear of any potential pitfalls that we may run into along the way and generally any advice that you ...
5
votes
1answer
504 views

Installing and enabling both master and slave semisynchronous plugins on same server

I want to run a semisynchronous replication setup, and for simplicity I'd like to not have to INSTALL and UNINSTALL plugins when a slave is promoted to a master. So I'm wondering if I'll experience ...
2
votes
1answer
449 views

How to ensure that date-range queries involving multiple time zones are sargable

I am building a web analytics application for search engine traffic only. You can see some screenshots here: http://myhappyanalytics.com/ It works similar to Google Analytics but it only saves and ...
1
vote
2answers
917 views

mysql replication delay very serious

We use a ssd disk for master database and SATA disk for slave. On high write load (300 writes/s), slave delay is very serious. I have set: innodb_flush_log_at_trx_commit = 0 increased ...
1
vote
1answer
385 views

MySQL-5.5 InnoDB memory issue

Version in use is mysql-5.5.24. In the Enterprise version of MySQL innodb_buffer_pool space is released after a while, however this does not appear to be happening in the community version. I am ...
1
vote
1answer
435 views

Select records that do not have associations outside a certain list

I have a mySQL table of nodes and each node can be associated with many categories. I have a list of category ids that are acceptable (498, 499). I want to select only nodes who do not have ...
2
votes
1answer
706 views

How to add additional tables/fields into a query with multiple inner joins?

Given this query (many thanks to RolandoMySQLDBA from question Select records that do not have associations outside a certain list), how do I add other fields from other tables into my result? SELECT ...
0
votes
2answers
1k views

How to use and optimize subquery on 100 million rows

What I'm trying to do is running a job on more than 100 million domains which haven't processed before. I have two tables, "domain" and "domain_setting", on every batch (10.000 domains per batch) I'm ...
1
vote
2answers
505 views

mysqlslap chokes on strings that contain “;” delimiter?

I'm having a problem passing preexisting files full of SQL statements into mysqlslap. For example, I have a file named create.sql that contains my table structure (as dumped by mysqldump), with ...
1
vote
1answer
706 views

Queries getting stuck on very simple COUNT queries

process list: | 16004 | metrics | xxx:64616 | metrics | Query | 29064 | Sending data | SELECT COUNT(*) FROM Plugin where LastUpdated >= '1356856200' | ...
0
votes
1answer
2k views

Lock wait time out exceed restart transaction

I had got error on the lock wait time out so below I got 3 samples taken. One I took before the increase innodb_lock_wait_timeout to 120. So is there anything else I must tweak based on the logs ...
2
votes
1answer
1k views

Load different date formats in mysql

I have a date field in my datafile which I am trying to load in MySQL, but the date field is in dd-mon-yy format and MySQL only understands YYYY-MM-DD. Is there a way by which I can load DD-MON-YY ...
2
votes
1answer
120 views

To make a LVM backup of a MySQL database, would I have to reduce the logical volume size?

I am trying to learn how to do a Ubuntu LVM backup of a MySQL database. For this test I installed a fresh copy of Ubuntu 12.04.2 LTS on a new box, along with MySQL 5.5. The box has one hard drive. ...
2
votes
2answers
301 views

Why does adding LIMIT to my query make it crawl?

Simple query: select sum(score) total,name,gender,dob,country from users join scores on users.id = scores.user_id where date between '2012-01-01' and '2012-01-31 23:59:59' group by scores.user_id ...
0
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0answers
187 views

Req: Typical location of mysql query cache

My MVC framework (CodeIgniter) wants to know where my database (mysql 5.5) writes its query cache. My Ubuntu installation is unexceptional. Would that be /var/lib/mysql/ or further down the chain, ...
2
votes
1answer
1k views

What is the syntax for querying a spatial column?

What is the right syntax to get all the points within the bounding box? The table consists of a lat and lng column and a spatial column "pt" generated from the lat/lng values. calculated the topleft ...
0
votes
1answer
1k views

Query that ranks students order by marks and give the position of student even when there are students with equal marks

I need an sql that will rank students order by marks scored in a specific examtyp e.g CAT1 and give exact position even if the students have equal marks e.g in this sample data admNo 2525 and admNo ...
1
vote
1answer
262 views

Master updates Slave but not Master itself

I have a setup master/slave in which applications are pointed only to master. Yesterday Master had got crashed due to "multi bit error on dimm detected" in Front indication panel in orange color. ...
2
votes
2answers
500 views

EMS SQL manager permission problem

I have a strange problem with EMS SQL Manager. I'm using MySQL 5.5 with linux servers. One of my developers need to edit store procedure, so I grant him: GRANT CREATE ROUTINE, ALTER ROUTINE ON ...
3
votes
1answer
87 views

How can I get this query to use it's index?

Queries matching this query below shows up in the slow log (with different contentVersionId & modifiedDateTime). As I don't really know what I'm doing I tried adding indexes to all columns in ...
10
votes
2answers
16k views

What is the reason of Host 'host_name' is blocked in MySQL?

When I use incorrect password to connect to mysql server, and the test count is over the max_connect_errors, and I find the Aborted_connects is also arise as the count I test, but the host is still ...
4
votes
2answers
3k views

Trigger in MySQL

Please help me for few question in SQL.. I want to create the trigger which prevents insertion in the reservation table of flights (numflights), which does not exist. Tables ...
4
votes
3answers
2k views

How to change data structure in mysql using mysqldump without deleting files

Essentially what I'm trying to do is sync a production server with a sandbox server, but only the table structures and stored procedures. The procedures aren't any problem since they can be overriden, ...
4
votes
2answers
4k views

Is it okay to use rsync on InnoDB database if the MySQL server is shutdown?

Is it okay to use rsync on InnoDB database if the MySQL server is shutdown ? For example : /etc/init.d/mysql stop rsync -av /home/mysql/mydb/ root@newserver.com:/home/mysql
-1
votes
1answer
109 views

Why is this mysql query wrong? [closed]

I try to run the following sql query in mysql SET @rank:=0; WITH TEMP ( SELECT @rank := @rank + 1 AS ROW_ID , UUID() as RANDOM_VALUE,D.* FROM house_information_new D ORDER BY ...
0
votes
1answer
625 views

upgrade mysql 5.1 to 5.5 on Ubuntu 11.10

I currently have mysql server 5.1 installed via apt-get on my production Ubuntu 11.10 server root@Ubuntu-1110-oneiric-64-minimal$ dpkg --get-selections | grep sql-server mysql-server ...
1
vote
0answers
222 views

Enforce a hard limit on write execution time during Amazon RDS write stalls

I am trying to recover from the situation where Amazon RDS write operations stall (some discussion on why this is here). If I show full processlist, I will see something like this: 318263 myapp1 ...
3
votes
1answer
4k views

MySQL high CPU usage (MyISAM table indexes)

I have a problem with an inherited MySQL database. From time to time mysqld uses up to 2300% CPU.. The only solution is to service mysql stop and run an myisamchk -r on a table. After the indexes have ...
2
votes
1answer
985 views

Table corruption: How to perform Innodb Checksum checks in MySQL 5.5 for Windows?

Having a corrupted Mysql 5.5.31 (Windows) database, my question relates to the the top solution provided in How do you identify InnoDB table corruption? , more precisely to the following script that ...
0
votes
0answers
1k views

MySQL installation broken after Windows crash - how to repair MySQL and recover data?

recently my PC powered off abruptly for no apparent reason, leaving my Windows 7 installation severly damaged. I can still log onto the machine, but tons of Windows system files have been corrupted ...
1
vote
1answer
1k views

selecting the month day and year from a transaction table

i want to create two queries for my table which has fields name,surname and amount paid,the first query should select the day,month and the amount paid,the second query should select a month,year in ...
1
vote
1answer
378 views

Why do MySQL MyISAM table indexes go out of date?

I have few MyISAM tables, where only the auto_increment primary key is up to date with the number of columns, but not other indexes. Any idea, why this happens?
2
votes
1answer
982 views

Trigger doesn't run when value of a column changes from null to 1

I have this trigger: delimiter $$ create trigger tr after update on t1 for each row begin if new.col1 !=old.col1 then update t2 set col2 =1 where t2.col3=t1.col3; end if; end $$ This ...
2
votes
2answers
2k views

How to tune mysql to be inmemory-like

I've given MySQL 5GB of memory (I use innodb), but when I insert lots of data (dumpfile is 1GB), hard drive I/O is still a bottleneck (CPU is not busy and hard drive is). Is it possible to force ...
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votes
2answers
499 views

Challenge: Build MySQL table that's not in first normal form [closed]

I have read numerous books and articles about database design and SQL in which it is said that a database should be in first normal form (1NF). (Some then go on to describe situations in which it may ...
0
votes
2answers
434 views

Using MySQL InnoDB as an Archive

My site has a main MySQL InnoDB table that it does most of its work on. New rows get inserted at a rate of 1 million per week, and rows older than a week gets moved over to an archive table on a daily ...
3
votes
1answer
113 views

Question about MySQL Semisynchronous Replication

I was researching about MySQL Semisynchronous Replication, my understanding about the workflow is the follow: Master Receive a successful transaction from a client session. Master write it to his ...
0
votes
1answer
4k views

How to check which tables in DB (MYSQL) updated in last 1 hour / last 1 minute?

I have to create a xls datafeed for a website and I would like to know which tables are getting affected when I do a manual entry from CMS. If i have installed fresh database and I'm doing first ...
0
votes
1answer
100 views

mysqlbackup mysql enterprise utility issue

I recent took a backup using mysqlbackup. While restoring it, I noticed that the files that were copied into datadir are with root:root (user:group) instead of mysql:mysql. Is anything wrong with ...