MySQL : Open-Source, Relational Database Management System

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What's the approach to figure out reason for mysql crash?

The database I'm using crashes a lot recently. And I can't find a decent way to dig into the issue. I looked into mysql error log, but don't know how to start. I know there was a "load data infile" ...
2
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1answer
34 views

MariaDB Spider Engine Out of Memory

I had almost standard MariaDB with InnoDB engine working fine but I wanted to test out the Spider Engine + Sharding/Partitioning. I had a query which was passing fine on the MariaDB InnoDB for ...
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2answers
108 views

MySQL Monitoring Script in Shell or Perl for Linux

I need a MySQL Monitoring Script in Bash or Perl for Linux. I found some but they are quite big with a lots of checks that are not useful at all for me and in this case I should customise the ...
2
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1answer
91 views

Two queries usually run fast but get slow when joined

There are those 2 tables CREATE TABLE IF NOT EXISTS `media` ( `mid` int(11) NOT NULL AUTO_INCREMENT, `user` int(11) NOT NULL, `order_type` int(11) NOT NULL, `media_id` varchar(50) COLLATE ...
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0answers
7 views

Innobackupex: How to extract individual files from xbstream compressed backups

We are scripting a mix of full and incremental backup setup for our prodcut backend with sunday triggering full backup and incremental backup on all the remaining days. In this process, we should be ...
0
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1answer
140 views

How to restore data after MySQL Upgrade?

I upgraded from MySQL 5.5 to 5.6 by uninstalling 5.5 and then installing MySQL 5.6. Now that MySQL 5.6 is running, none of my DBs or data is present/visible in MySQL Workbench. I also see that I ...
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1answer
26 views

Is my shopping list database schema good enough?

So Im wondering if my schema is correct? It's basically suppose to hold shopping list items for each user, a user belongs to a household. Items will be added to the household. The stocklist is ...
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0answers
31 views

How to use multiple conditions using AND and OR in WHERE statement? [on hold]

how can I apply a multiple conditions in my WHERE clause using AND and OR? What is the best way to apply this? My scenario looks something like this. ...
0
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1answer
153 views

increasing disk space for mysql data volume

I have a master mysql server which has approached 80% of the available disk space. Total disk space size is 200GB. Though, it's not an immediate concern but I have to deal with at some point soon. the ...
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2answers
36 views

HeidiSQL: Import CSV

A few lines of my CSV: "id","date","date_","pow","ene","reac" "ES0134000563024539AM0F","2013-05-02","2013-06-05","62","43","43" "ES0134000573024539AM0F","2013-05-02","2013-06-05","62","43","43" ...
0
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1answer
1k views

MySQL Workbench Cannot start SSH tunnel manager [on hold]

I don't know why this error is happening when I try to connect by MySQL Workbench. Cannot start SSH tunnel manager. I'm using slackware 14.1 and installed all dependencies. I already installed the ...
0
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1answer
1k 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 ...
2
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1answer
18 views

Plotting graphs for MYSQL

I was executing following command mysqladmin ext -i1 -c3600 It produces valuable output but I want to use the output to plot graphs so that I can visualize inserts, updates, buffer and other stuff. ...
0
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1answer
130 views

ubuntu - Pm2 mysql high cpu usage

Not sure what is going on here but would love some help if any can. I am running on digital ocean 1GB ram ubuntu server a node.js application that is is launched with pm2 and that uses a mysql ...
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0answers
22 views

MySQL Query with good execution plan is very slow due to Sending data operation

I have the following query: SELECT a.borrowerId AS borrower_id, a.created, NULL AS initiator_team_id, NULL AS initiator_user_id, NULL AS old_team_id, NULL AS old_user_id, ...
0
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1answer
169 views

MySQL-How to find that value in a column is subset with all other values in same column multiple time

I have a table named as Team where table contain 3 column (ID,Team,Task). Its datatypes are (INT,VARCHAR(255),INT). Below you will find a sample table where I would like to perform the query on column ...
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0answers
12 views

MariaDB multi-master replication (star topology) - Bizarre out-of-sync behavior

This may look familiar, I've been learning about this stuff for a few days - but this is a new question. I have a setup like this: Every node is a master, and I have them all replicating to each ...
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3answers
238 views

What's faster: two UPDATEs with WHERE (in / not in) or one UPDATE with CASE?

What's best performance wise, two separate UPDATEs: UPDATE table1 SET enabled = 0 WHERE code NOT IN ( SELECT id FROM table2 ); UPDATE table1 SET enabled = 1 WHERE ...
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0answers
26 views

MySQL: is it more efficient to query for duplicate row or insert(update) on duplicate?

Just curious on resource efficiency. If I have a list of inserts that need to be accomplished repeatedly which may contain duplicates (there is no way around this, the API I have to work with sucks), ...
0
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1answer
23 views

Mac OS X 10.10 mySQL 5.6.26 accessible from CLI but not port 3306

I did a fresh install of mySQL 5.6.26 on my Mac today. I was able to access mySQL from Terminal.app as expected, however I could not get mySQL workbench to attach to 127.0.0.1 port 3306. What really ...
0
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1answer
181 views

MySQL Subquery Returns Null In Stored Procedure, Works Fine In Query

I have a subquery in a MySQL Stored Procedure where the value returns null even though the data is clearly there. Pulling the subquery out and running it works fine. I've checked the parameter values ...
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1answer
16 views

MYSQL find if a default value has been set for a table (DateTime Specifically)

I am trying to internationalize a database, but there are places where the timestamp that gets set is using NOW() instead of UTC_TIMESTAMP(), and it's using Amazon's RDS with multiple MySQL servers. ...
3
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0answers
39 views

MySQL Commited data not seen to select query

Context: The framework used is Spring and all queries are run with JdbcTemplate. Mysql Server version is 5.6.19. The table is an InnoDB table and defaults like auto commit and isolation level ...
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2answers
138 views

Recommendation for the mysqldump?

I have approx 90 GB of database, I need to schedule a mysqldump backup , thats why I Required a recommendation how much time it takes for the full hot backup? Because I didn't taken that much size of ...
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2answers
26 views

MySQL Multi-Master Replication Topology

Disclaimer: I've never worked with replication before, but I'm doing all my research. Not really having a bunch of in-depth knowledge about MySQL makes a lot of the documentation hard to understand. ...
0
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1answer
242 views

MySQL data transfer to different schema

We have two servers: one for the developer (me) and one for the tester. While working on the app, I sometimes make little changes in tables's schemas. (Like a new field, or a field type) I'm trying ...
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3answers
157 views

MySql Invoice and Subscription Schema

I have an ecommerce db built and I'm adding subscriptions. See the simplified structure below. orders id, customer_id order_items id, order_id, product_id invoices id, order_id subscriptions id, ...
1
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1answer
36 views

Which technology to synchronise SQL Server and MySQL data?

Which technology should be used if I want to move my data from SQL Server to MySQL server when data is entered to SQL Server row by row and getting feedback from MySQL server? Should it be 1. ...
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1answer
27 views

MySQL connectivity error

I have a MySQL database on a Linux server that I am able to access through putty logging into servers terminal. When I try to connect to the MySQL database remotely, I get the error: Lost ...
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0answers
12 views

Write operations on the RDS Mysql Database becomes Slow during long run load test [on hold]

I'm having serious performance problems with MySQL and the InnoDB engine in long run load test. Even the simplest table makes writing operations.I'm using Amazon RDS m3.xlarge instance for performance ...
2
votes
1answer
204 views

Threads_cached 0 while thread_cache_size > 0

I'm trying to little bit understand with some MySQL (in my case - MariaDB) performance. One point I found - "threads caching". So - I set: thread_cache_size = 4 in my.cnf and restart server. In ...
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2answers
173 views

why does mysql query running slower on server? [on hold]

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 ...
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2answers
189 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 ...
2
votes
1answer
159 views

Rich text: VARCHAR, TEXT or BLOB in MySQL

Question: In my web application (php/MySQL) I will be saving rich text. This may be anything from a couple words to several pages length essay. I’m sure I could get away with using VARCHAR, TEXT or ...
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0answers
47 views

Tuning MySQL query from explain

I am working on a search query in MySQL. I am getting this from explain: Original screenshot These are my indexes: Table definition: Original screenshot Query: SELECT `t`.`id` AS ...
2
votes
1answer
25 views

MySQL server won't start with foreign_key_checks=0

I'm running Ubuntu with MySQL version 5.5.44 mysqld Ver 5.5.44-0ubuntu0.14.10.1 for debian-linux-gnu on x86_64 ((Ubuntu)) I have a DB with foreign keys. I would like to have the foreign key ...
1
vote
1answer
160 views

MySQL replication using a lot of IO

I'm having big troubles on a database pool I've setup recently. There is a master, and 4 slaves replicating one DB. All using MyISAM engine. Thing is, during the replication period (when the slave ...
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0answers
17 views

Demoting a MySQL Master to Slave [on hold]

I recently had to fail my master over and promote a slave due to a network outage. All of that worked fine. Now that the network is back, I'd like to add my old master as a slave of the new master. ...
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0answers
19 views

How can I get the latest value per unique ID, then count the number of entries with that value? [on hold]

Ok, so I have a table that has device_id, lots of other stuff, and network_type. I currently run the following query: SELECT partner_name, COUNT( IF( network_type='ethernet',network_type,null )) AS ...
1
vote
1answer
20 views

Migrating all MySQL databases from from one server another. Getting error during import

I create a mysqldump on all the databases on the source server with this command: mysqldump -h mysql-01 -u root -p --all-databases > newdump.sql This takes about an hour, but runs fine. Now, ...
7
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3answers
109 views

Why NOT partition?

When would one NOT want to partition a database? (thinking MySQL partitioning) In my case I'll be starting with a couple millions rows, it should grow from there. Primary key on a character field ...
0
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1answer
22 views

inner join on true

My table: abc +--------+ | letter | +--------+ | a | | b | +--------+ Query: SELECT * FROM abc t1 INNER JOIN abc t2 ON true Result: +--------+--------+ | letter | letter | ...
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2answers
599 views

Can't get mysql running

After canceling an Ubuntu upgrade, Mysql refuses to start. this is what I get when I try to run it : $ mysql ERROR 2002 (HY000): Can't connect to local MySQL server through socket ...
1
vote
3answers
110 views

Prepopulate database with empty / null values [mysql]

What would be the best way to pre-populate a database with 100 empty fields and then begin the Auto_Increment? What I mean to say, I want to reserve the first 100 userfields (ie UIDs which are ...
0
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1answer
8 views

MySQL / DRBD / Pacemaker on EC2

I am trying to setup DRBD/MySQL/Corosync/Pacemaker on AWS EC2 instances, though I am not sure if it will work since how to integrate VIP is a problem for me. Anyone have any thoughts on what to do ? ...
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0answers
20 views

what is update cascading exactly in sql? [on hold]

We have three table declarations for P1(A), Q1(B) and R1(C) with referential integrity in SQL. create table P1 (A primary key); create table Q1 (B primary key references P1(A) on update ...
2
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0answers
219 views

How to encrypt user passwords for forum registrations? [migrated]

What is the most secure way to encrypt user passwords for phpBB or MyBB forum registrations? I don't want anyone to be able to access the user passwords, not even those who administrate the MySQL ...
2
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1answer
15 views

Should the Redo log on a production MySQL server be configured to another location?

Concerning the innoDB storage engine, should the innodb_log_group_home_dir option (The directory path to the InnoDB log files) be configured to another disk, other than the default directory, in order ...
2
votes
1answer
109 views

MySQL Delete Rows from Slave

I want to truncate the majority of data on a slave such that it only has the most recent records. I'll eventually demote the current master, making it a read-only archive, and promote the truncated ...
1
vote
1answer
25 views

MySQL Matching records across tables discrepancies

I have a database called match, within this database I have a number of tables. Of which in particular I need to marry up two datasets in different tables to identify email addresses that are not ...