MySQL : Open-Source, Relational Database Management System

learn more… | top users | synonyms

0
votes
1answer
18 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
22 views

Impact of replication compression & encryption on performance, traffic?

What is the impact of MySQL compressed-slave-protocol on replication traffic? According to High performance MySQL it can lower the traffic to a third of the same replication without the compression. ...
0
votes
2answers
61 views
+100

MySQL schema for recurring events - Query by specific date

I've just asked this exact same question on stackoverflow so apologies for cross posting but I only just noticed dba so thought I'd ask across here as well. I'm just about to start putting together a ...
2
votes
1answer
26 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 ...
2
votes
1answer
22 views

MySQL behaviour on connection failure

My MySQL database is hosted on a different machine from my application system, which issues queries to the MySQL database remotely. If for some reason the network connection between the two machines ...
0
votes
0answers
20 views

Concatenate extrapolated data from two tables

I want to concatenate two tables that contain user data. The purpose is to display the duplicate user accounts based on email, IP address and connection logs. The two tables containing user data (I ...
1
vote
1answer
34 views

Determining replication traffic

is there any way to determine from server statistics* running MySQL, how much traffic(bits per second) WOULD replication consume between 2 servers, without setting-up the actual replication between ...
0
votes
0answers
27 views

MySQL wont start after abnormal shutdown

I had an abnormal shutdown of the server, when I started it again I get this errors. If I remove ibdata1, ib_logfile0, ib_logfile1 its starts, but the databases aren't there...I can't restore a ...
0
votes
0answers
22 views

Auto Increment Column for Ordering

I have the following table and I just added the ord column because I need to ORDER BY ord all of my tasks selected for a user/group. I want them to always be returned in the order the user added the ...
0
votes
1answer
18 views

Trying to recover/import/transfer database from MySQL data dir

I used phpMyAdmin->export to create a backup of my database but I have now discovered it did not export the whole database, some tables was missed/refused. However at the time of doing the export I ...
1
vote
0answers
24 views

Table already exists error when trying to import sql file

I am trying to upload a backup sql file through phpMyAdmin. I create the empty db with the same db name as in my import file in phpMyAdmin then use the import function selected from within this empty ...
1
vote
1answer
55 views
+50

Replication from EC2 Master to RDS Slave - Connecting to master

I am migrating my company's database from an EC2 instance to an RDS instance. I have already migrated a snapshot of data and am now trying to set up replication to get the data that has been added ...
0
votes
2answers
67 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
0answers
15 views

MULTIPLE INSERT VALUES with INSERT into another table

here a scenario to have a more clear picture. The DB is MySQL. I've 2 tables events and *event_users* : EVENTS id int type int date date time time ... EVENT_USERS event_id ...
-1
votes
0answers
18 views

MySQL indexing types? [closed]

i am newbie for php and mysql developement still don't make any indexing because don't have idea about that. how to use the mysql indexing. mostly used indexing method is what?
1
vote
0answers
48 views

Best database for fast read all in one table

I currently have a large database in SQLite that I was using for rapid-prototyping for a software I am working on. Now that I am planning to move it to another database that should give better ...
-3
votes
1answer
33 views

How long will it take to import 28 millions rows in a MyISAM table? [closed]

Someone has idea how long time it will take to import? I hear something like 40k each minute? Thanks.
0
votes
0answers
14 views

#2002 Cannot log in to the MySQL server / Connection for controluser as defined in your configuration failed

I use PHP/MySQL in Ubuntu 13. To reduce the size of ibdata1, i followed this post What is the best way to reduce the size of ibdata in mysql? and make necessary changes as told in the answer. I did ...
-2
votes
1answer
25 views

How does InnoDB store tables in ibdata file? [closed]

There are two tables and their default engine is InnoDB. I want know the following What's inside the ibdata file ? How does InnoDB store these two tables ?
0
votes
2answers
54 views

why does mysql query running slower on server?

select glpi_tracking.id AS gi, glpi_tracking.date AS gdate, glpi_tracking.closedate AS cdate, glpi_tracking.contents AS gc, glpi_followups.tracking AS gft, glpi_followups.date ...
1
vote
2answers
23 views

Large MySQL table that need to index some fields?

I would like to know some hints about how to indexing some fields of a MySQL Table that has about 28 millions of rows. Maybe i could recreate the table indexing it properly then import these rows? ...
3
votes
1answer
21 views

Is it possible to remove useless GRANTS in MySQL

I'm using pt-show-grants to create all my GRANTS on a new server but there's lots of old GRANTS that refer to tables that doesn't exist anymore so I get errors when I try to apply the SQL file on the ...
0
votes
1answer
18 views

Should I create a new instance of amazon rds or just a new schema inside of it?

I'm fairly new to Amazon Web Services and one of my customers asked me to install several things for them on EC2. I would normally use the same box as webserver and database server, mainly for ...
1
vote
2answers
62 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 ...
1
vote
1answer
38 views

MySQL master master replication, safe to delete rows on both masters?

We have a MySQL (v5.1.61) cluster with two masters (and two slaves). We have a table logs with a primary key column logID. This log table grows rather huge, and we'd like to delete data from it. So ...
0
votes
0answers
30 views

MySQL silly query plan [duplicate]

I'm using 5.6.15-56-log Percona Server. Here's my table(which has over 5M records) CREATE TABLE `promotion_codes` ( `id` int(11) NOT NULL AUTO_INCREMENT, `code` varchar(255) DEFAULT NULL, ...
4
votes
1answer
34 views

MySQL silly query plan

I'm using 5.6.15-56-log Percona Server. Here's my table(which has over 5M records) CREATE TABLE `promotion_codes` ( `id` int(11) NOT NULL AUTO_INCREMENT, `code` varchar(255) DEFAULT NULL, ...
0
votes
0answers
17 views

Using triggers to sync databases

Is it more reliable to use triggers to sync 2 mysql database that has different structures than doing it on an application level? See related question at stackoverflow. How would you sync 2 mysql ...
0
votes
1answer
14 views

MySQL Server 5.6 only runs when making swapfile

I am new to MySQL server and I have setup a dedicated MySQL server. I am aiming to install MySQL server version 5.6 and since version 5.6 is not available on the Ubuntu repository I have to upgrade it ...
0
votes
0answers
18 views

MySQL 5.5 InnoDB migration using stored procedure is very slow in Linux/Windows 2008 Server

I am Migrating MYSQL data from one server to another server using my stored procedure. The target server is Linux//Windows Server 2008. The migration speed is extremely poor. It takes about 5-6 ...
0
votes
0answers
11 views

started using cleardb and curious to see if way to verify that heroku connections are via ssl

I'm hooking up ClearDB's MySQL for Heroku and have set up SSL connections via provided certs / keys but am curious if there is any way to verify that the heroku-cleardb connection is running over ...
0
votes
1answer
28 views

How to prevent MySQL to consume much memory soon after Windows7 startup?

When I turn on my desktop (Windows 7 SP1), I often find 2 or 3 GB of memory is already occupied by MySQL processes. I don't care about how much memory a database requires, if it actually runs some ...
0
votes
1answer
31 views

MySQL - prevent OS cache for query

On high load production server I have many sql selects which are unique or re-use will be in hours. I use SQL_NO_CACHE but this queries are still cached with OS cache. Server have 64G ram and used ram ...
0
votes
0answers
17 views

help me restore a database

I have a database backup that I'm trying to load so that I can extract some historical averages. I think it was a MySQL database, but with some syntax adjustments I was able to create the one and only ...
0
votes
1answer
35 views

How can i import 150GB database after deleting ibdata1,logfile in MYSQL?

I have 150GB database and my ibdata1 file size is 240GB so i want shrink the ibdata1 file so for that i have to export the DB and then drop the tables and then stop mysql, delete the ibdata1 file and ...
2
votes
2answers
15 views

where is the index physically located in MySQL database

Just wondering where is the index info physically located in MySQL database if I have indexed a table with ALTER TABLE contacts ADD KEY (columnName); ? it will stay with that table and add a new ...
0
votes
3answers
70 views

MySQL vs. Microsoft Access [on hold]

I'm trying to aggregate about 500-1000 MS Excel files that deal with various small business issues (inventory, purchase orders, etc) and I'm currently trying to decide what kind of RDMS I should use. ...
0
votes
0answers
14 views

Performance : MySQL replication or only one big server?

I'm searching about the best choice. We have to host a website with 10.000 - 20.000 visitors per day actually, growing. At the beginning, which would be the best : Having 2 MySQL servers (12 GB ...
0
votes
0answers
17 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 ...
0
votes
0answers
20 views

While Loops Don't Work in MySQL 5.6?

I'm trying to use a while loop in MySQL for the first time, and decided to create a simple example as a test: BEGIN SELECT 0 INTO @n; WHILE @n < 10 DO SELECT @n; SET @n := @n +1; ...
1
vote
0answers
18 views

Move all InnoDB databases into one subdirectory (innodb_file_per_table is ON)

First of all, excuse my English. I want to run a MySQL 5.6 on ZFS volume, and need to move all InnoDB databases to one subdirectory (which in fact will be a different ZFS filesystem). For example, by ...
1
vote
1answer
100 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 ...
0
votes
0answers
17 views

mysql synchronisation

hello, i have 5 MySQL servers masters each one have mysql slave , and i have to synchronize data from those masters to one other mysql(central mysql who contain the common data : it can be ...
0
votes
0answers
7 views

mysql synchronization databases

hello, i have 5 MySQL servers masters each one have mysql slave , and i have to synchronize data from those masters to one other mysql(central mysql who contain the common data : it can be ...
0
votes
1answer
32 views

Optimize this query: SQL

I have this query in MySQL: SELECT p.idSentence, p.idPath, p.token, p.posTag, p.ner, p.isTV, r.relationType, t.tag FROM path p LEFT OUTER JOIN relation ...
0
votes
0answers
19 views

Can I set a lower_case_table_names value for a specific database?

I'm running a MySQL 5.5 on Linux (Debian 7) with several databases. I need to import a database originally maintained in Windows MySQL using sqldump. My issue is that this database is used by a ...
0
votes
2answers
37 views

How to fix slow LIMIT queries with big offsets without heavily rewriting them?

Imagine a very basic example of your average discussion board. For example: CREATE TABLE threads ( id INT UNSIGNED NOT NULL AUTO_INCREMENT, title VARCHAR(100), PRIMARY KEY (id) ) CREATE ...
1
vote
0answers
7 views

Is it possible for unique key to break master-master replication in mysql?

I have a master-master mysql setup with 2 servers running the exact same application making writes to such a table: CREATE TABLE `metric` ( `id` bigint(20) unsigned NOT NULL AUTO_INCREMENT, ...
-1
votes
2answers
54 views

When do I need transactions /locks?

I know that transactions are meant to group several operations as one. But if for example in the same table one transaction does DELETE FROM table where state = 'done' and another does either SELECT ...
0
votes
0answers
29 views

Why does the delete/update block each other in this case?

The following drives me crazy. I have: session1>begin; session2>begin; session2>update dummy set salary=1000 where id=11; session1>delete from dummy where id=1; id is the PK ...