RE: io thread very slow copying binlogs

Hi Brad, > MySQL community edition 5.6.29, running Linux. > > Binlogs never seem to get caught up on slaves. > > I've done all I can, to validate that this isn't network or disk related. > > Disk tests (using iostat and other methods) show lots of bandwidth left on > the slave and master. > >

Re: MySQL 5.7 Innodb performans issue

Hi Jørn, > Found this after I found out what caused it: > > https://www.percona.com/blog/2009/01/21/beware-ext3-and-sync-binlog-do-not-play-well-together/ > > I suspect that this also apply to ext4, or? I would go more specific and say that sync_binlog=1 does not play well with single-threaded

Re: MySQL 5.7 Innodb performans issue

Hi Jørn, >> - The data collector system processing jobs, is it multi threaded? > > Sorry, forgot about that. No, it is not multi threaded. It is a PHP bases > system using several > script running sequently in an infinite loop. Each script taking care of part > of the job of > processing the

Re: MySQL 5.7 Innodb performans issue

Hi Jørn, Wagner’s point about SHOW ENGINE INNODB STATUS is a good one. A couple of other questions about your workload: - The data collector system processing jobs, is it multi threaded? - Do you have a sample schema + set of queries we could look at? (We pay close attention to regressions.)

Re: Query time taken on disk

Hi Satendra, On Jul 14, 2014, at 3:48 AM, Satendra wrote: > Hi there, I'm struggling to find the total time taken by a database query > on the disk? As I understand when a database query start execution it takes > some time inside the database engine & some time to seek the result from > disk (i

Re: SHOW FULL COLUMNS QUERIES hogging my CPU

Hi Jatin, On Jun 2, 2014, at 7:56 AM, Jatin Davey wrote: > I found this blog while trying to find a fix for my problem. Thought it might > be useful to share. > > Here it is: > > http://whirlpool.net.au/blog/5 To confirm - did you manage to fix your problem? I was about to comment that it l

Re: Performance boost by splitting up large table?

Hi Larry, On May 14, 2014, at 5:05 AM, Larry Martell wrote: > We have a table with 254 columns in it. 80% of the time, a very small > subset of these columns are queried. The other columns are rarely, if > ever, queried. (But they could be at any time, so we do need to > maintain them.). Would I

Re: Precedence in WHERE clauses.

Reindl, >> The order of the WHERE clause does not matter > > that is simply not true > > otherwise that documentation would not exist > http://dev.mysql.com/doc/refman/5.5/en/multiple-column-indexes.html Yes, the order of the columns in composite indexes *does matter*. This is a different que

Re: Precedence in WHERE clauses.

Hi Christophe, > Considering the following simple query : > > SELECT * FROM Status WHERE DWProcessed = 0 AND PreviousStatus NOT IN > ('PENDING', 'ACCEPTED') AND SubscribeDate < DATE_SUB(NOW(), INTERVAL 24 > HOUR); > > Which of these filters are processed first ? > > I'd like the first filter (D

Re: SHOW CREATE TABLE suddenly slow on InnoDB?

Hi Brad, > We actually only have about 60 tables in that database. I've tried increasing > the cache and open tables limits and get the same behaviour. Hmm.. Shawn’s guesses are probably better than mine then. > A few other tests I've tried: > > 1. Stand up a new machine, dump just the schema

Re: SHOW CREATE TABLE suddenly slow on InnoDB?

Hi Brad, > That sounds right. Here's the process list (scrubbed) and the show engine > innodb status. Notice that all of the SHOW CREATE TABLE aren't for hte same > table, just got cleaned up that way. It shouldn't matter if they are for the same or different - in 5.5 there is one table open cac

Re: SHOW CREATE TABLE suddenly slow on InnoDB?

Hi Brad, > I'm trying to figure out how InnoDB executes a SHOW CREATE TABLE query so I > can figure out what could possibly have made them suddenly slow down? > > mysql> SHOW CREATE TABLE `my_table`; > ... > 1 row in set (37.48 sec) > > We tend to execute many of these statements concurrently, b

Re: New to MySQL

Hi Asma, It looks from this error that there is an existing 5.1 installation present. As well as RPM packages (which can be downloaded from http://dev.mysql.com/downloads/mysql/5.6.html), there is also a yum repo for Enterprise Linux 6. It is available here: http://dev.mysql.com/downloads/repo

Re: Crash after shutdown/restart

Hi Jørn, >> I would say that this sort of performance drop is not typical. Some >> users have reported a smaller performance loss in single threaded >> workloads in 5.6. > > But dropping from an average of 1800 jobs per minute down to 300? I don't > think that should be expected. I would agree

Re: LIKE sql optimization

Hi Zhigang, On Feb 11, 2014, at 8:48 PM, Zhigang Zhang wrote: > I want to know the reason, in my opinion, to scan the smaller index data has > better performance than to scan the whole table data. I think I understand the question - you are asking why MySQL will not index scan, find matching

Re: error - ould be looked up with ./bin/resolveip

Hi Érico, > mac:mysql-5.6.16-linux-glibc2.5-x86_64 ericomtx$ sudo > scripts/mysql_install_db --user=mysql > sh: ./bin/my_print_defaults: cannot execute binary file > FATAL ERROR: Neither host 'mac.local' nor 'localhost' could be looked up > with > ./bin/resolveip > Please configure the 'hostname'

Re: MySQL 5.7 release plan/date

Hi Igor, > When MySQL 5.7 planned to be released as stable/production ready? We do not provide planned release dates. If I can recommend a video to watch about the release process, please watch Tomas Ulin’s Percona Live keynote April 2013: http://www.youtube.com/watch?v=OpHTV59I1gs Watch from

Re: Index Query Tunning

Hi Anupam, We are keep on getting deadlock due to index locking, there is index on FLAG, we can allow phantom read in session 1, we tried with READ COMMITTED but still same, I think issue with next-key locking. Did you try setting binlog-format=ROW as well? I have a brief explanation of thi

Re: Crash after shutdown/restart

Hi Jørn, But I must say I'm not very impressed by the speed. I'm running a test on an application that do a lot of reads and writes queries and the general performance has dropped to 50% of the what I had in 5.5.20. I would say that this sort of performance drop is not typical. Some users hav

Re: Foreign-key reference

Ugh, that seems quite right. Now, why did they do that? It was added for compatibility. A separate specification is less convenient, and also less transparent. Please click "affects me" on http://bugs.mysql.com/bug.php?id=47771 - Morgan -- MySQL General Mailing List For list archives: ht

Re: Foreign-key reference

On 1/6/2014, 12:21 PM, h...@tbbs.net wrote: Are INNODB foreign-key references ignored in 5.6? You might be hitting: "Important The inline REFERENCES specifications where the references are defined as part of the column specification are silently ignored. MySQL only accepts REFERENCES clauses