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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1
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1answer
41 views

pass data from deleted table to another

This is the situation: I have a table, with name TABLE_1 I would like delete TABLE_1 and then create another table with the same name and some of its columns. TABLE_1 has records, but I need to pass ...
0
votes
1answer
394 views

Inheritance discriminator column better int or varchar or enum?

What is the best practice for storing a discriminator column ? Does it make any difference ? Any pros/cons of using one over the other ? I am using MySql with Entity Framework but the question goes ...
1
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2answers
454 views

Get only the oldest entry in a join

So I have a table bugs |bugid| title| the table is lacking a date column. But when creating a new entry, most likely always a new entry gets created in bugnotes as well saying "bug created" with the ...
0
votes
1answer
52 views

Auto refreshing a query

I have a SQL statement update test_1 set `t_mark` = (`mark_1` + `mark_2` + `mark_3`) which works perfectly but I want the same statement to repeat automatically when a new row is added.
4
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2answers
15k views

Restoring MySQL Tables from .ibd, .frm and mysqllogbin files

For some reason, when I try to open up my tables that are stored in .frm and .ibd files (whether on MySQL or phpmyadmin) it gives me a syntax error or it says it does not exist. I've read the other ...
-1
votes
1answer
552 views

Btree index and Bit Map Index [duplicate]

Please clarify the difference between BitMap Index and Btree index. I am using mysql version 5.5.37-0ubuntu0.12.04.1. I can able to create Btree index but unable to create the same, Please find the ...
1
vote
1answer
394 views

MySQL Cluster MaxNoOfConcurrentOperations and RAM

Why increasing of MaxNoOfConcurrentOperations lead to higher consumption of RAM? I need high value for fast filling tables with some random data, but i noticed that my datanodes are swapping at ...
1
vote
1answer
237 views

MySQL Cluster ndb_desc and parttions

I have mysql cluster with two datanodes and noofreplicas=2. According to documentation there must be 1 nodegroup, 2 partitions and 4 parts at all (2 primary and 2 backup). I have a table with 1000000 ...
2
votes
1answer
9k views

MySQL: Create multiple tables with one query

Can you list multiple table names in a MySQL CREATE TABLE query? CREATE TABLE table1, table2, table3 LIKE table_template; If so, can you do it with the IF NOT EXISTS clause? CREATE TABLE IF NOT ...
0
votes
1answer
330 views

how to view the Image in mysql DB

Hi How to retrieve the image in mysql I had created a table employee_details CREATE TABLE `employee_details` ( `emp_id` int(50) NOT NULL, `emp_name` varchar(50) NOT NULL, `dept` varchar(50) ...
2
votes
2answers
928 views

How to monitor InnoDB Disk I/O using Server Status Variables?

This question is extension of my previous question "How to monitor InnoDB Disk I/O Required for MySQL? " As mention in my previous question i want to count total number of disk i/o per query, but ...
0
votes
1answer
51 views

How to connect to remote MySQL server with sshuser and mysqluser being distinct

I'm trying to connect to a remote MySQL server via ssh so that I have write-access to export some data. At the moment I can do the following: Connect to the remote MySQL using mysql -u mysqluser -...
1
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0answers
107 views

MySQL WRITE LOCK Not Preventing Inserts

This should be a simple task. Can someone tell me why the below code is still inserting rows? lock table wp_postmeta write; insert into wp_postmeta values (null, 1,'test','test'); I've checked my ...
0
votes
2answers
141 views

Query Cache Implementation Details

I am new to DBA stack exchange & this is my first question. Kindly help me in finding a low level documentation for Query Cache module in MySQL since I am planning to work with the source code of ...
2
votes
1answer
684 views

Load csv into MySQL database programmatically

I know about LOAD DATA INFILE command -- however, this requires that we already have the table with appropriate columns in place. When I have csv with hundreds of columns, it is not feasible to type ...
0
votes
1answer
276 views

How to simulate a table join on itself?

Let's assume this is my current data: product_number date value 100 2010-01-01 1 100 2010-02-01 1 100 2010-03-01 1 200 2010-01-01 1 ...
0
votes
1answer
55 views

How to optimized mysql query having large dataset

I have two tables in MySql with the following schema, CREATE TABLE `open_log` ( `delivery_id` varchar(30) DEFAULT NULL, `email_id` varchar(50) DEFAULT NULL, `email_activity` varchar(30) DEFAULT ...
1
vote
1answer
24 views

Select the last logged change before a specified time from a change list

I want to get the last change for all issues issue, that was made before a specified end time. I have 3 tables. projects +---+------------+ |ID |project_key | +---+------------+ |1 |bug_tracker | +-...
0
votes
1answer
52 views

Could not access database

I have been trying to setup a local instance for a new application. I am new to MYSQL and I cannot understand how to actually connect this database to the actual web application sitting in the /var/...
5
votes
3answers
5k views

Strange MySQL database that I can't select

I am investigating a web site server (CentOS release 6.3) that runs the traditional lamp stack; I am getting the following output my MySQL; mysql> show databases; +--------------------+ | ...
0
votes
0answers
677 views

MySQL is running but not working [closed]

In an attempt to tune MySQL to make it work with a recent installation of Drupal I had to modify the MySQL settings on my server. After modifying the configuration file for MySQL (/etc/my.cnf) MySQL ...
0
votes
0answers
96 views

Help with MySQL query which is only occasionally slow? Temp tables/Disc caching?

We have an issue with one particular query whch runs regularly on our MySQL database, though I am not necessarily sure it is a problem with the query itself. 90% of the time it runs perfectly fine ...
2
votes
1answer
144 views

MySQL Stored Procedure Requiring SUPER

I'm trying to figure out a "safe" way of allowing a non-SUPER user to execute a specific command requiring SUPER privileges, i.e. SET SESSION binlog_format = 'MIXED'. I don't want to grant the user ...
1
vote
2answers
47 views

MySQL describe | more

With my current setup, it's going to be very hard, if not impossible, to get my terminal window to scroll up and down. That means I can only see 25 rows of text at once. If I have to display something ...
2
votes
2answers
94 views

I need help optimizing a not that complicated query that returns unexpedcted performance problems

I have a table that stores details about incoming and outgoing phone calls such as when a call was made, or when a call was received, the phone number of the caller, and the phone number of the ...
0
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2answers
236 views

Database search with multi joins

I have a MySQL database and I want to perform a little bigger search. I have about 10k records in one of the tables and It's expected to grow, but slowly. The biggest problem is that to perform the ...
0
votes
0answers
21 views

MySQL Is there a performance difference between col = val and col IN (val)?

Is there a significant performance difference, or any other reason why I shouldn't write, for example: SELECT * FROM table WHERE col IN (val); Instead of: SELECT * FROM table WHERE col = val; I ...
1
vote
1answer
137 views

my phpMyAdmin data is hashed or hexed?

I have a mySQL db setup in MAMP in which I connected mySQL Workbench to administer the design of the database. When I inserted some data today from within myPhpAdmin (localhost:8888), I noticed the ...
1
vote
1answer
2k views

MySQL Syntax - Searching points within polygons using GeomFromText

I am trying to select points within polygons using the GIS/spatial extensions for MySQL. I'm fairly new to this, so bear with me if this is an elementary question. I have points defined as text ...
5
votes
1answer
613 views

Percona MySQL 5.5 Unique key is duplicated

I'm totally out from ideas, so maybe somebody else could answer my question. We have a MySQL 5.5 server from Percona with high traffic. The application is in PHP and writes always to master. We have ...
0
votes
4answers
2k views

Converting to MyISAM, `foreign_key_checks = 0` Not Working

At the end of a long series of compromises working in a system I didn't design, own, or maintain, I need to convert a number of MySQL InnoDB tables to MyISAM tables. However, when I attempt to alter ...
3
votes
1answer
722 views

Efficiently searching geolocations - LAT/LNG and DECIMALs

I have a database with > 7.5 million rows (and growing), each with an image record that has a specific LAT/LNG geolocation representing where the photo was taken, stored as DECIMAL values - mysql&...
1
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3answers
250 views

How could I improve query to take less than 4s on ~10M records?

I have to select id_category and its name, description and link_rewrite where number_products > 0. However it selects 1000+ rows where only 10-20 of them have number_products > 0, others are 0. ...
0
votes
0answers
67 views

Select and sum from related columns

I have table with the following columns: date (month), hours/days (31) and daily tasks (31) Columns: date day1 day2 day3....task1 task2 task3.... Records: june 4 6 2 .... run walk ...
1
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2answers
316 views

getting one day timestamp in mysql

Please consider the following stored procedure I have: ORIGINAL Stored Procedure: -- -------------------------------------------------------------------------------- -- Routine DDL -- Note: comments ...
0
votes
1answer
44 views

Problem with foreign keys

I do ALTER TABLE bdt.auth ADD CONSTRAINT `depositor no.` FOREIGN KEY ( `depositor no.` ) REFERENCES bdt.depositors( `depositor no.` ) ON DELETE CASCADE ...
1
vote
1answer
292 views

How to make the SQL query more efficient?

I use mysql under Linux. My table is about 8000000 rows. The table has index(advertiser_id,activity_date),(activity_date,advertiser_id,activity_type). The table is looks as following: activity_date ...
0
votes
1answer
479 views

MySQL Update Multiple Rows in Large Table

I have a large InnoDB MySQL database table. I would like to run this query against the database table: Update myBigTable Set someColumn=x WHERE userId = 7 OR userId = 88 OR userId = 22 OR userId = 99;...
3
votes
2answers
8k views

Is there a way to tell your hostname within a stored procedure?

Is there a way to determine the hostname of the server you're running in w/ in a stored procedure? You can run system hostname from a client but you can't make system calls from SP. I don't see it ...
0
votes
1answer
99 views

Help optimizing very slow mySQL query

I have a query which takes about 6 secs to execute. SELECT * FROM (SELECT ord.ID, op.name AS prodName, op.code, ord.date, ord.email, op.total, stat.ID AS statusID, stat.value AS status, user....
0
votes
1answer
23 views

Creation of a simple field failed in MySql [duplicate]

CREATE TABLE bdt.transactions ( `transaction no` int UNSIGNED NOT NULL AUTO_INCREMENT, data date , by int NOT NULL , hours int NOT NULL , ...
-1
votes
1answer
375 views

“Backup mysql database by copying the data file even when MYSQL server is running” solution! Is there any problem for this backup solution?

I am using MYSQL-5.0.27 I have 2 exact same MYSQL folder "mysql-5.0.27-win32". One in the Virtual Private Server (VPS) & the other in Local PC. At the beginning, these 2 folders are exactly the ...
0
votes
2answers
474 views

Parent/child relationship or not if the name of the field implies the relationship?

I am working with the harmonized system and try to catalog this in a MySQL database. This works for example like this: 01 LIVE ANIMALS 0101 horses, asses, mules and hinnies, live 0102 bovine ...
0
votes
0answers
183 views

MySQL insert Needed data only then send it to crystal report

I'm Working on a big project more than 200 table, I'm using MySQL(Percona), Java & Crystal Report JRC. I have some reports which so big & has a lot of joins between multiple tables. Inside the ...
0
votes
1answer
293 views

Exporting Very Large Database from mysql 5.5

Before I proceed, I would like to confirm can I export a very large table of 3.6GB size using the MySQL Admin Export feature. I have exported tables of small size like 28 MB but just wondering ...
0
votes
1answer
4k views

How to join 3 tables together given 2 many-to-many relationships tables in between?

I have 3 main tables: Person, Publication and Conference and 2 many-to-many link tables in between: person_publication and person_conference I want to join all 3 main tables together (showing me all ...
0
votes
1answer
2k views

MySQL row-based-replication HA_ERR_KEY_NOT_FOUND… which record is it?

I have a mysql slave (5.1) using row-based replication. The slave has stopped with the error HA_ERR_KEY_NOT_FOUND. OK fine, it's trying to update a record that doesn't exist for some reason. Using the ...
0
votes
2answers
47 views

primary_key problem in MySql view

I have 3 tables. and I want to create a view. There is no problem about generating SQL qeury and creating a view. but when I want to use this view in my web app it says me (LIKE THIS): "your view's ...
6
votes
4answers
1k views

Making a column immutable in MySQL

I want to make a column in a relation unmodifyable for consistency reasons. The backstory is that I have a n:n relationship where the "connecting" relation has additional values. I don't want that ...
0
votes
1answer
48 views

Which file in “MySQL-5.0.27-win32” folder do i need to backup?

Ok, I am using a pretty old MYSQL "mysql-5.0.27-win32" and the file and the structure maybe different from the latest Mysql (mysql 7). Here is the current structure of of mysql-5.0.27-win32: In "...