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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0
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2answers
214 views

Connect MySQL workbench with MySQL container

I pulled MySQL container from Dockerhub and it is running on my macbook pro as you can see as follow CONTAINER ID IMAGE COMMAND CREATED STATUS ...
0
votes
0answers
21 views

How can I restore a MySQL dump faster on Windows?

I am restoring some InnoDB and MyISAM .sql files that are on the order of GBs (ranging from 1 GB to ~ 10GBs) and they are taking a day or longer to restore. The command I am using currently is: use ...
0
votes
1answer
42 views

Copy table form MS-SQL server to MySQL, is it possible? [closed]

I have a procedure, say "proc1", inside a MS-SQL server. I would like to create a table (copy of proc1) inside a MySQL server. So far what I do is this: 1-Create a connection to MS-SQL Server 2- run ...
0
votes
1answer
651 views

Can't Delete Orphaned MySQL Temp Table

One of my servers had a hick-up yesterday and decided to leave temporary table while (while running alter table add indexes). ls -l sql -rw-rw---- 1 mysql mysql 8570 Mar 13 12:05 #sql-ib32694.frm ...
1
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0answers
29 views

Does mysql's `SHOW PROCESSLIST` appreciably slow down other queries?

I'm just wondering if my measurement of the processes is affecting the speed of the processes. I was testing alternative methods of copying a database. 1.) mysqldump followed my mysql mydb < ...
1
vote
1answer
197 views

How can I remove references to tables after removing .frm files?

So I had a bunch of csv files in my /var/lib/mysql/imports directory for importing into mysql tables I had created. To clean up the folder I deleted all the files in the directory (incorrectly ...
0
votes
1answer
30 views

Staging MySQL databases

I'm building a Web/Web service application based on a number of (MySQL) databases. The databases are all built from externally derived data from dozens to hundreds of sources. My general plan is to ...
2
votes
1answer
1k views

Issue when connecting to open shift via mysql workbench on Mac

I am trying to connect to open shift with mysql workbench on an iMac. A colleague has shown me his setup on Windows which looks exactly as follows (other than the usernames / passwords changing) ...
0
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0answers
13 views

Reliability of MySQL Events Table

Is there any limitation of usage of MySQL Events table. Let us say i will have 10K of entries which will be executed across 3k schemas. They all are not same time but at-least 3K events will be ...
3
votes
1answer
76 views

mysql custom query logging for inter-software data exchange

Some 2-3 years I had written some triggers (one per table) in SQL server allowing me to log queries in our main software. ALTER TRIGGER [dbo].[SUIVI_REQUETE_CAT_CATBRUT] ON [dbo].[CAT_CATBRUT] AFTER ...
1
vote
1answer
108 views

Delete rows where matched value is twice as much

I'm trying to match two tables with two columns, table1 and table2. Each has id and price columns. I want the query to match each id and compare the price, then delete the row if the price in the ...
3
votes
1answer
7k views

Why does MySQL (InnoDB) table get faster after OPTIMIZE TABLE, but then don't work?

I have a Django web application that stores data in a MySQL InnoDB database. There is a particular page that is accessed a lot on the django admin, and the query is taking a long time (~20 seconds). ...
2
votes
1answer
177 views

Can Unicode columns include non-Unicode values in SQL Server?

I need to convert Unicode column values from UTF16-LE to UTF-8 to then import into MySQL. Is it safe to assume columns of NVARCHAR, NTEXT, NCHAR, BIT, INT, DECIMAL, FLOAT, and DATETIME all must be ...
1
vote
1answer
314 views

Speeding up a simple select query on Mariadb

I have a 100k rows table with the following structure: +----------+------------------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | ...
1
vote
1answer
54 views

Does INFORMATION_SCHEMA always contain up-to-date metadata?

This query prints the size (in terms of data and indexes) of the tables in mydatabase: SELECT table_name "Table name", round(((data_length)/1024/1024),2) "Data size", ...
3
votes
1answer
140 views

How to get data from two different tables? [closed]

I have these two MySQL tables: tab1: +-----------+-------------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | ...
0
votes
1answer
1k views

Mariadb on Centos 7 not changing max connections based on my.cnf

The following configuration in my.cnf is not being followed. Max_connections go back to 151. please help as i have 16gb of dedicated ram that i would like to use properly. [mysqld] ...
0
votes
1answer
500 views

Mysql can't write to filesystem

I need to output some queries as csv files. The directory is in the webroot and I want it to be writable by apache too, so I'm trying to add mysql to the www-data group (on Ubuntu). I thought this ...
6
votes
0answers
171 views

Single table with more columns vs multiple tables with fewer columns

What would be a better database design for a social network website? A single table with more columns and fewer rows, or multiple tables with fewer columns but more rows? For example: A user can post ...
0
votes
1answer
4k views

How to UPDATE a column to SET previous row value to NULL cells?

I have a table as id value 1 music 2 3 movie 4 5 6 book 7 8 Some values are missing, and I want to assign the value of previous row to produce id value 1 music 2 music 3 movie 4 ...
1
vote
2answers
44 views

mysql query gets slower with increasing page number

I use laravel 5.2 with mariadb (ARIA engine) and found that my query for creating a gallery gets slower with increasing page number. select `pics`.`id`, `pics`.`title`, `pics`.`hits`, ...
3
votes
2answers
3k views

Merge multiple columns into one column in different table?

I've done this before, but I don't remember how. I need to select all rows from several columns in one table and insert them into one column in a different table while keeping them all on separate ...
0
votes
1answer
34 views

MYSQL: weird bug with nested stored procedure

I have two stored procedures. The first one fetch language codes in my language table. CREATE PROCEDURE `updateCategoryNameAll` ( IN categorieNumber VARCHAR (10), IN categoryName VARCHAR (128) ) ...
0
votes
2answers
31 views

how to insert values in a table with foreign key field

I am creating a database where I have a table with a foreign key. I am using the following command: insert into ques_bank (q_no, uid, question) values (NULL, select uid from user_info ...
3
votes
2answers
92 views

Tuning MySQL variables to accommodate high load

My site is generating error 500s to users when load is high ("cannot allocate memory" errors appear in my logs). I have a VPS with GoDaddy, 8GB RAM (on average only about 40% of RAM is being used at ...
0
votes
0answers
22 views

MySQL Table Structure for Group User Permissions

I could use some assistance in restructuring the schema on mysql for more granular permissions. We have a website where for example there is data for site 1, 2, and 3. There are users A, B, and C. ...
0
votes
1answer
170 views

MySQL select data over time that matches pattern over several rows

We currently log data from our plants running remotely for diagnostic purposes on MySQL. I have been asked to come up with a typical running profile for several variables. For this, I would require ...
0
votes
1answer
31 views

Phpmyadmin / mysql error defining primary keys as foreign keys of two separate tables

I am designing a mysql database using phpmyadmin 3.3.10.4. Everything in the database is InnoDB. I have two tables, person with primary key person.id_numberand e-mail_address with pk ...
0
votes
1answer
427 views

MySQL 5.6 replication causes 'waiting for table lock'

All of the sudden queries on slave server stopped with status "Waiting for table level lock" I restart mysql service and stop replications and locking does not show up anymore. Once I turn ...
-2
votes
0answers
28 views

Guys I need lost data from master to slave after resyncing [closed]

First the replication was running fine but after some time replication got broken for 10hrs and after that i re sync to slave its running fine but what about the 10hrs data?????
0
votes
0answers
18 views

MySQL replication slave master [closed]

working on sync project using MySQL i'd like to replicate specific table rows from slave to multi masters What is done: Replication from masters to slave work perfectly Aiming for : Now we consider ...
0
votes
1answer
921 views

How to update a (very) large table without locking in MySQL

I have a large table (58+ million records) which represents a relation between two records (player and target) in a second table. Unfortunately, whoever designed our schema didn't think things ...
0
votes
2answers
47 views

Un-optimize a MySQL database?

I want to run ANALYZE TABLE and OPTIMIZE TABLE on a large production MySQL database (v 5.0) to increase performance. But as this would lock tables causing downtime for an unknown amount of time, I ...
3
votes
2answers
260 views

Avoiding Multiple Queries when Searching for Records Associated with a Set of Records

So, I am sure I have done something really stupid while designing this, and I'm open to schema changes if they'll really help me out. On to the problem: I have a custom shopping cart system (backed ...
0
votes
1answer
785 views

MySQL failover - Master to Master Replication

My company is trying to implement a MySQL failover mechanism, to achieve higher availability in our webservices tier - we commercialize a SaaS solution. To that end we have some low-end VMs scattered ...
1
vote
2answers
242 views

Can we disable binary logging for one specific session or user in AWS RDS

Currently we have a situation to disable binary logging for one set of queries on AWS RDS. We thought to set log-bin=0 for that specific session. As per Amazon, this is not possible. Is there any work ...
0
votes
0answers
29 views

Can we update mysql database table through .csv file And pls update not loading data from .csv [closed]

I have a mysql database table and I am updating few elements of an attribute of the table trying to do this by importing .csv and then what should be the approach as the csv file contains the updated ...
0
votes
1answer
309 views

MySQL Cluster error on UPDATE: increase MaxNoOfConcurrentOperations

I had a table with ~0.5M rows and tried to exec simple query, something like UPDATE table SET col1=-90 + RAND()*90, col2=-180+RAND()*360 WHERE col1=9999 but result was ERROR 1297 (HY000): Got ...
32
votes
4answers
34k views

Is it safe to use innodb_flush_log_at_trx_commit = 2

I turned innodb_flush_log_at_trx_commit = 2 and get a very fast write speed. But is it safe be used in production web site?
2
votes
1answer
615 views

How to restore database from /var/lib/mysql

I have a database folder from a crashed server called gain_wordpress. I'm trying to put that database on a new server but I'm not able to do it successfully. I don't have a .sql dump, all I have is ...
1
vote
0answers
39 views

Data nodes stuck at starting

After updating the config.ini (I updated my MaxNoOfAttributes, MaxNoOfTables, MaxNoOfOrderedIndexes,etc.) on my management node and running the ndb_mgmd with --initial command. I can't seem to start ...
1
vote
0answers
18 views

implement geo / spatial / proximity search with php and mysql — what have you done successfully

For my website's users, I want to implement a worldwide geo / spatial / proximity search with php and mysql. I want to do this as simply and minimally as possible. What is the minimum data I should ...
0
votes
1answer
241 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 ...
0
votes
2answers
133 views

MySQL binary logging with just one log file?

I have a MySQL database running with binary logging turned on. Each time the database is restarted a new binary log file is created in the format : mysql-bin.00001 mysql-bin.00002 ... mysql-bin.0000n ...
0
votes
1answer
361 views

pt-table-checksum - Verify MySQL replication integrity

export/import: $ mysqldump -h6dhdbm01 -p clee2 users > 6dhdbm01-clee2.users.sql Enter password: $ echo $? 0 $ mysql clee2 < 6dhdbm01-clee2.users.sql $ echo $? 0 $ pt-table-checksum: $ ...
0
votes
0answers
13 views

MySQL 5.6.27 keep logging ERROR : Got an error reading communication packets

I have a two nodes MySQL replication set with M1-M2 configuration. The MySQL version is 5.6.27. After deployed and the application(which is jboss 7) connected the M1 and ran few queries for ...
7
votes
0answers
104 views

Avoid MySQL self-crashing on long semaphore waits

I run heavy queries on my InnoDB databases every night, and sometimes it causes long semaphore waits. More background in this question. What I have observed is that if the data is stored on an SSD, ...
1
vote
2answers
26 views

Correct way to write this view? Total sales/purchases/profits by day

I'm currently trying to create a view that lists a sum of sales, purchases and profits done by each person per day. This data comes from 3 tables: transaction: idtransaction (pk) user_iduser (fk) ...
3
votes
2answers
294 views

How to get the sum of a particular item id in a column [closed]

Item ItemName PackageID Specifics brandname GRNQty UnitPric GRNValue 102814742801 ALL BRAN FLAKES 1PKT Bran. KELLOGS 7 15.9 111.3 102814742801 ALL BRAN ...
0
votes
1answer
3k views

How to convert a MySQL database from utf8mb4 to utf8?

I would like to convert a MySQL database, which has utf8mb4 character set and utf8mb4_unicode_ci collation, to utf8 and utf8_unicode_ci. How to do that please? Thank you in advance for your ...