MySQL : Open-Source, Relational Database Management System

learn more… | top users | synonyms

1
vote
0answers
57 views

MySQL - Cannot add new Foreign Key

I'm using magento and it does some re-index for a product flat table structure. In this process a new table is created. The SQL for that table is something like: CREATE TABLE ...
1
vote
0answers
51 views

How to set the trigger when field(contain json value) is updated?

I have one table in which there is one field called info.This field hold json value. I want to create trigger on this field.I want to split this json format string into record I mean I want to insert ...
1
vote
0answers
19 views

Custom cycling order in MySQL

Having following Foo table: id | name | group ===|=========|====== 1 | "John" | 1 2 | "Paul" | 1 3 | "Marry" | 1 4 | "Josh" | 1 5 | "Mike" | 2 6 | "Kevin" | 2 7 | "Ramon" | 2 8 | "Kim" ...
1
vote
0answers
70 views

MySQL InnoDB Configuration with 60Gb of Memory

I'm running a large MySQL Database, in the range of 30Gb in size. The MySQL 5.5 server is running on a dedicated server with 60GB of RAM, with no other processes installed apart from monitoring tools, ...
1
vote
0answers
49 views

Is there any way to improve this code?

SELECT tblstud.studid, tblsched.ip FROM tblstud LEFT JOIN tblstudsched ON (tblstud.studid=tblstudsched.studid) LEFT JOIN tblsched ON (tblstudsched.schedid=tblsched.schedid) ...
1
vote
0answers
91 views

Can MySql cause a Windows server to shutdown unexpectedly?

For the 3rd time, my server where my MySQL instance is running simply shutdown unexpectedly, this time, causing my tables to be corrupt as I had ALTER statements running. While in contact with my ...
1
vote
0answers
43 views

adding a new partition takes a long time

I am adding a new partition and it takes too long to get this task done. ALTER TABLE attribute_usage_information ADD PARTITION ( PARTITION AUI_2015001 VALUES LESS THAN (735964) ) I am new to MySql ...
1
vote
0answers
82 views

Connection error except with SQLYog

I have a problem connecting with the database with PHP or with MySQL in Linux . I can only connect to the DB with SQLYog. The error I'm getting is this: SQLSTATE[HY000] [2003] Can't connect to MySQL ...
1
vote
0answers
125 views

To configure MySQL Enterprise Workbench for Incremental Backup with Online Backup option

Could not acquire management access for administration RuntimeError:Could not initialize WMI interface: Workbench.wmiOpenSession():Could not connect to target machine. When i am trying to configure ...
1
vote
0answers
135 views

Using Netscaler datastream and MySQL

I configured MySQL service on a netscaler 10.5. When I perform some MySQL benchmarks using mysqlslap, the first time it runs correctly, the 2nd time I have an error message: When I run it the first ...
1
vote
0answers
33 views

Can MySQL Index Merge an Composite index with a single column index?

I am tuning a query and currently have an index as following : Index 1 : (col1, col2) An example query would be : SELECT * FROM t1 WHERE col1 = '1' AND col3 = '2'; I have created an index on ...
1
vote
0answers
109 views

25.000+ rows - MySQL SELECT consecutive numbers performance issue

I have tried to be as explicit as I could. Below you have the query explained in details What I want to obtain? - I want to SELECT start_number and end_number from a set of consecutive numbers from ...
1
vote
0answers
126 views

two column compare ,get count(*) of two column A value same cloumn B value

I have a Mysql table as --------------------- -- page - user -- --------------------- -- page a - user 1 -- -- page a - user 2 -- -- page a - user 3 -- -- page b - user 1 -- -- page b - user 3 -- ...
1
vote
0answers
103 views

MySQL calculate overlapping period excluding overlapping rules

I would like to calculate the period overlap in hours based on special rules. I created a test setup, that works as long as the rules themselves don't overlap. Example non overlapping rules: id ...
1
vote
0answers
54 views

Multilanguage category structure - standard vs. normalization?

I'm building a multilingual application and I need some advice on how to structure the table. Basically I have a category table based on nested set. There are 4 languages and I plan to enlarge this ...
1
vote
0answers
55 views

Sysbench insert data between a given range

I was trying to insert 1000000 records of data into 1000 tables in sysbench. But after installing about 278, sybench just crashed with the following error: FATAL: failed to execute function ...
1
vote
0answers
146 views

Are ZRM (Zmanda Recovery Manager) incremental backups reliable?

I had an issue while restoring incremental backups and I'm wondering if they are reliable. I'm making weekly full backups and daily incremental backups and I needed to restore a single database after ...
1
vote
0answers
55 views

Migration error: “Invalid date literal detected” when reading decimal

I'm attempting a migration from MSSQL to MySQL and keep coming across a "Invalid date literal detected" error when reading certain decimal columns. I'm running the following (all up-to-date as of ...
1
vote
0answers
177 views

Migrate from SQLite to MySQL (then back)

For various reasons, I must use a SQLite database with a local application. However, I wrote a Flask app that enables users to more easily classify items in the database, and it runs very slow on ...
1
vote
0answers
22 views

Need advice on optimizing database on a recurring basis

I have a search engine with approx 3.5 million rows in the searchable table. There are many suppliers that feed into the table each day, so primary keys are constantly being removed and added and the ...
1
vote
0answers
48 views

Handling this multi-threading scenario in the database?

I am working on sample bus ticket booking application,in I am facing these two multi-threading scenarios. Scenario 1 1: Let's say there are two users, they both pick a particular seat and submit ...
1
vote
0answers
22 views

MySQL - Transactions and causality

I'm new to MySQL's LOCK and TRANSACTION and have a question about different isolation levels of a transaction: Given two transactions executing the same code (auto-commit is false): (1) get data of ...
1
vote
0answers
106 views

Handling SQL updates for production deploys

I'm researching for quite a long time now (about two months) and haven't found a good approach for this, so I'll ask you experts out there in the hope of some enlightenment. I run a pretty ...
1
vote
0answers
43 views

Can't seem to optimize joined select query

Can't seem to figure this one out. Query is taking upwards of 7-8 seconds which is just not acceptable and seems as though it will get worse as the table(s) get larger. Without going into a ton of ...
1
vote
0answers
84 views

MySQL table partition strange behavior (slow query suddenly)

(I asked this question in "stack overflow" and was recommended to ask in here). (MySQL version: 5.6.15) I have a huge table (Table_A) with 10M rows, in entity-attribute-value model. It has a ...
1
vote
0answers
66 views

MySQL not using multicolumn index on self join

I'm trying to optimise a query that performs an inner join with itself. The table size is currently 10GB ~50 million rows. /* Count all occurrences between start and end site id of a given speed ...
1
vote
0answers
353 views

Lost Connection to mysql server at 'reading authorization packet', system error 0"

OK, this has been bugging me all afternoon now, I have a new MySQL Database '5.5.40-0+wheezy1-log' running on Debian Linux. It is to all extents and purposes a clean install. I have created two ...
1
vote
0answers
31 views

Any way to mitigate the large server load during LOAD DATA LOCAL INFILE operations?

I'm using MySQL LOAD DATA LOCAL INFILE to load csv files, and have noticed that during these loads, server output speed to other users diminishes eg long page download times, logins timeout. The LOAD ...
1
vote
0answers
58 views

Skipping stopwords (and indexing small words) for one fulltext index only, in MySQL

I have a rather odd situation where it might be preferable to not use stopwords and to have a value of ft_min_word_len equal to 1. The index in question would be dealing with only a few words per row ...
1
vote
0answers
112 views

MySQL permissions or privileges (User does not have access to metadata required)

I am using MySQL and I need to give one user to web service for access database. The web service need all permission related to stored procedure, like procedure execution. I executed the following ...
1
vote
0answers
127 views

“Unexpected EOF” during SELECT on huge MyISAM table

When executing a SELECT query that uses filesort on a huge table (2 billion rows) the execution stops after ~30mins with the following error message: ERROR 9 (HY000) at line 1: Unexpected EOF found ...
1
vote
0answers
178 views

How can I correct MySQL replication while using federated tables?

This is an overview of what I have going I have 2 server A (10.0.4.22) AND B (10.0.4.29) A is a replication of B and B is a replication of A (yes it is a ring replication) ON A I have 2 table uat and ...
1
vote
0answers
77 views

MySQL event scheduler doesn't work

I have the following MySQL event sheduler to udpate some values in RECETAS table's ESTADO column. I want to run it everyday at 10:05:00. CREATE EVENT IF NOT EXISTS actualizar_prueba ON SCHEDULE ...
1
vote
0answers
49 views

Combining fields to make a unique record or keeping them separated

I've been asked to implement what has before, been a bunch of CSV files, into a MySQL database. I'm at a point in the design where all the schemas, tables and fields have been mocked-up; however I'm ...
1
vote
0answers
47 views

Copying to tmp table slow for query … but only sometimes

I have a query, and I admit it may not be the prettiest query in the world. Sometimes this query runs fairly fast (e.g. 200ms) and other times it runs super slow (e.g. 30s). I don't know why, and ...
1
vote
0answers
32 views

MySql Audit Changes from Db Admin, Security

I know that you can use triggers (before insert, update, delete) to track the changes in history tables. But this only works if the changes are made by the applications. But in some circumstance, ...
1
vote
0answers
31 views

How to calculate geographic distances using MySQL

Given a MySQL table with a series of latitude and longitude points, stored as strings, how can I find the distances between each point in the table and a given point, call it "originlat, originlon" ? ...
1
vote
0answers
20 views

Conversion to Barracuda/Compressed Rows Doesn't Free Disk Space

I'm currently converting large tables to the Barracuda file format. We are using file_per_table. I had one table that decreased from 4.3gb in size down to 1.8gb and we're very happy about this. ...
1
vote
0answers
109 views

Best practice for storing image order number in a database

I am designing a social networking website(mysql with InnoDB engine + php) where I need to store image sequence in a database. The table structure is as follows:- PicId (BIGINT, AUTO INCREMENT, PK) ...
1
vote
0answers
79 views

Indexed query fails to return rows in large (15 billion rows) MyISAM (MySQL) table

I have a very large table (15 billion rows) with a structure like this: CREATE TABLE `textlines` ( `PGUID` binary(16) DEFAULT NULL, `StatID` int(11) DEFAULT NULL, `Time` datetime(3) DEFAULT ...
1
vote
0answers
73 views

Tuning MySQL On Azure Windows Server Setup

I have a MySQL 5.5 running on Azure VM Windows Server 2012. Once per second the log db gets about 2K inserts through LOAD DATA INFILE... once a day I need to run stats and when the stats are crunching ...
1
vote
0answers
154 views

Database Migration with Liquibase using different DBMS

Our customer is using Oracle and we want to use MySQL for development. Therefore our MySQL Scheme has to be in sync with Oracle. I tried to use Liquibase, but I get problems at the time of applying a ...
1
vote
0answers
55 views

Mysql syntax error when i add on completion preserve

I have written this event in mysql DELIMITER $$ CREATE EVENT le_drop_database ON SCHEDULE EVERY 1 WEEK ON COMPLETION PRESERVE STARTS CURRENT_DATE + INTERVAL 4 - ...
1
vote
0answers
55 views

Many small queries or one single query

This is not exactly a question, more of a survey. Here at BlackBean we have a time series aggregation and analysis platform built on top of MySQL, where each client have your own database, and each ...
1
vote
0answers
49 views

MySQL Memory & max_connections Performance Tuning

So, our site runs WordPress and in the past few days we have been getting tons of spam comments etc. I believe that we are becoming the victims of some kind of bot army that has been crashing our ...
1
vote
0answers
172 views

How to measure bandwidth requirements for MySQL, Postgres, …?

TLTR: how to configure MySQL/Postgres to get a fair measurement of the I/O requirments for analytical queries? Hello, for certain database and especially database hardware experiments for want to ...
1
vote
0answers
26 views

Why do these two queries (which I think are equivalent) rely on different keys?

We have a query that we don't like, since it ends up doing a full table scan. EXPLAIN SELECT count(*) AS c, location.name FROM study LEFT JOIN location ON study.location_id = location.id ...
1
vote
0answers
221 views

Problem when using gtid with MySQL replication

I have faced to problem when using gtid in MySQL replication: "When @@SESSION.GTID_NEXT is set to a GTID, you must explicitly set it to a different value after a COMMIT or ROLLBACK. Please check ...
1
vote
0answers
91 views

One table for article comments, video comments and photo comments or multiple tables?

First DBA question. Greetings people. I hope I'm not duplicating a question but it's very hard finding database design related questions here (for multiple comment tables), as all 'design' questions ...
1
vote
0answers
467 views

Replication of a remote MySQL database to local MySQL database

I'm the developer of my employers corporate private website, a HTML5/PHP/CSS powered site for company reports etc. The site, hosted on a shared hosting package, connects to a remote read-only MySQL DB ...