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One of JEHOVAH's Witnesses (TV)

Seasoned MySQL DBA (SCMDBA) since 2007-08-11

Profile for RolandoMySQLDBA on Stack Exchange, a network of free, community-driven Q&A sites


10h
comment Sorting Table and get Position of row
You could mark this answer accepted by clicking on the checkmark at the upper left cornber of my answer.
10h
comment Sorting Table and get Position of row
I have QUERY #3 ready for you
11h
comment Sorting Table and get Position of row
That is what the QUERY #2. If that is not the right output, then what is the expect output ? Please put an example in the question. Regarding your question Will I have to iterate over the whole results to find the right user or is there a solution with mysql I get only 1 result?, yes you will have to iterate over the output of QUERY #2. Let me update that.
1d
comment Mysql binlogs exists, show binary logs is empty
If you run FLUSH LOGS; does it generate mysql-bin.000316 ?
1d
comment Sorting Table and get Position of row
The sum of times for User1 is 170 (50 + 20 + 100). That's right. The sum of times for User2 is 140 (10 + 60 + 70) not 100.
2d
comment Hierarcy Query Mysql
That code is not from me. That code is SQL Server's TSQL, which I don't know. This one (dba.stackexchange.com/a/7161/877) is my post.
2d
comment Hyperthreading & MySQL InnoDB Thread Concurrency Performance
@kommradHomer Never mind. You do not have to restart mysqld. Just run SET GLOBAL innodb_thread_concurrency = 0;. Then, add that setting to my.cnf so it is available after restarting mysqld. Again, you do not have to restart mysqld.
2d
comment Hyperthreading & MySQL InnoDB Thread Concurrency Performance
@kommradHomer What version of MySQL are you using ?
2d
comment Hierarcy Query Mysql
dba.stackexchange.com/questions/57934/…
2d
comment Hierarcy Query Mysql
dba.stackexchange.com/questions/7147/…
Dec
23
comment What is the best way to reduce the size of ibdata in mysql?
@StefanLasiewski If you post your situation as a separate question, I can try to answer it.
Dec
23
comment #1025 - Error on rename of table errno: 150 : Table was deleted while tried to assign foreign key
Please show the exact command you ran that generated the error.
Dec
23
comment What is the best way to reduce the size of ibdata in mysql?
@StefanLasiewski Yes, but please keep in mind that an InnoDB table still inside ibdata1 has no .ibd file outside.
Dec
23
comment Minimizing database size (Many small tables)
I am sure most of the tables have identical structures. Please post the distinct table structures into the question.
Dec
22
comment Pagination, check number of selected records
If cache_table the same structure as comments ?
Dec
22
comment SELECT returning NULL always
We also need to know the storage engine of the table. Please run SHOW CREATE TABLE user_information\G or SELECT engine FROM information_schema.tables where table_name='user_information'; and post the output.
Dec
22
comment SELECT returning NULL always
Please run the following query for us : select COUNT(*) nullrowcount,COUNT(1) rowcount from user_information;. What are nullrowcount and rowcount ?
Dec
22
comment Sorting by two columns conditionally
Looks like fun to me. +1 !!!
Dec
21
comment When is it safe to disable InnoDB doublewrite buffering?
Also keep in mind that turning off the double write buffer did not mean double writing does not take place. From the blog, that responsibility is being passed on to ext4 journaling. The result is faster double writing. You would need to do the PULL THE PLUG TEST yourself for your environment and see.
Dec
21
comment When is it safe to disable InnoDB doublewrite buffering?
I have seen that post months ago. I enjoyed reading it and I don't disagree with it. You will need make sure you use specific hardware, OS settings, and MySQL configs. The post did say: As always, test thoroughfully, I only tested on Ubuntu 14.04. You should test it too.