maximum database inserts/second (2 replies)
I am working on a php project that is expected to have 1,000 active users at any instance and i am expecting 1,000 inserts or selects per second. The question is, if my table uses innoDB Engine and...
View Articlemysql Query that splits a string into various potions (2 replies)
I would like you to help me with a query that can split string of words into groups of two. For example in a column i have 10 names, and these are of 5 people. They are separated by a space. So i...
View ArticleWhen to create Tablespace? (3 replies)
Hi, I would like to ask when do you recommend to create Tablespace? for example, what if my database is becoming large? should I create multiple tablespaces? Thanks, Jassim
View ArticleTypes of log maintained by innodb (2 replies)
Does innodb maintain two different logs namely redo log and undo log ? I learnt about redo logs from here https://blogs.oracle.com/mysqlinnodb/entry/redo_logging_in_innodb and about undo logs here...
View ArticleMySQL gets long semaphore locks on dict0dict.cc - but on DML operations (no...
Context: There is a table with 2 columns integer id column - primary key auto increment and a long text column. Rows are concurrently added, read and removed from this table by many different...
View ArticleStrange supremum gap-lock behaviour leading to deadlocks (no replies)
Hello! I recently discovered a deadlock problem in my application and went to investigate it. I managed to discover the cause and fix the code, but still this behaviour seems quite strange to me. So I...
View Article[MySQL 5.5.25] Can't upgrade from Antelope to Barracuda (no replies)
Hello, I am having the following errors when trying to add columns to one of my tables: "Error Code: 1118 Row size too large (> 8126). Changing some columns to TEXT or BLOB may help. In current row...
View ArticleAbort transaction when detecting lock (1 reply)
Hi, Is there a way to make a transaction immediately abort when it detects that another transaction has active locks on rows it targets, rather than reading a consistent snapshot or waiting for said...
View Articleconfigure for innodb variables (no replies)
Hi, I want to configure those innodb variables in mysql server. What is the proper values of these variables? How can I configure it? --------------------------- innodb-io-capacity...
View ArticleInnodb full table scan if query return 0 rows (8 replies)
hello mysql community i have a question about indexes in innodb i have a db with some innodb tables. the size of the entire db is about 1.5TB every table has about a bilion of rows the table index are...
View Article"Row size too large" error is triggering - when I don't think it should be (1...
I've got a bizarre issue with MySQL (specifically MySQL 5.5.5-10.0.26-MariaDB) where it is throwing the "Row size too large" error when (by my logic!) it shouldn't be. I have an ExpressionEngine...
View ArticleJack WH-"Row size too large" error is triggering - when I don't think it...
With a long line of text like your field_13_id data, Phorum renders the thread unreadably, so I started a new thread for this topic. The table structure is absurd. I'd immediately start looking for a...
View ArticleROLLBACK Segments found (no replies)
Hi, While looking through a log file on Workbench I noticed this item: InnoDB: 96 redo rollback segment(s) found. 96 redo rollback segment(s) are active Does this relate to the number of BEGIN /...
View Articleutf8 and utf8mb4 performance difference (1 reply)
As mysql document, Performance of 4-byte UTF-8 (utf8mb4) is slower than for 3-byte UTF-8 (utf8). To avoid this penalty, continue to use utf8 I want to know what's the performance difference, how...
View ArticleTRIGGERs using AFTER UPDATE are not updated (1 reply)
I am using Triggers to tell Windows processes that data in a specific table and record has changed and they should reread it. I have created a number of Triggers for various tables. One of the...
View Articlewhy transaction seems not work? (no replies)
Hi, test evn: 1.the mysql (in fact is 5.5.50-MariaDB), 2.write five million records 3.one record size is 400 bytes. test steps: 1. use the query("set autocommit=0") and query("commit") in the code,the...
View ArticleHow does MySQL still function even though I move .ibd file to arbitrary...
I have a table Person. AFAIU, the data for this table is stored in /usr/local/mysql/data/my_database/person.ibd. Now, I make an insert. Then I check out the contents of person.ibd with vim. The data I...
View ArticleMySQL 8.0: InnoDB (no replies)
MySQL 8.0: InnoDB - http://blog.sqlstunts.com/2016/09/mysql-80-auto-increment-feature-gets.html
View ArticleMySql Crash (no replies)
HI All, I am running load test on mysql (with innodb and memcached) and got following error/crash Version: '5.6.32-log' socket: '/var/run/mysqld/mysqld.sock' port: 3306 MySQL Community Server (GPL)...
View ArticleMysql Workbench crashing (no replies)
This is just a general complaint about the stability of Mysql Workbench. I am using the latest version 6.3, no updates found, and the application repeatedly crashes. I've never used an application...
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