Way back in May in the year 2000, a feature was added to MySQL that would keep many people employed for many years – replication. In 3.23.15 you could …[Read more...]
William Zola over at MongoDB gave a great talk called “The (Only) Three Reasons for Slow MongoDB Performance”. It reminded me of an interesting characteristic of updates in MongoDB. Because MongoDB’s main data store is a flat file and secondary indexes store offsets into the flat file (as I explain here), if the location of a document changes, …[Read more...]
As you should already know, Oracle had released MySQL 5.6.16
officially on January 31, 2014. You can find all the details in
official release notes. In this post I decided
to concentrate on important fixes for bugs reported by community
in 4 most important categories: InnoDB, replication, partitioning
Let's start with Bug #70768, "Persistent optimizer statistics often causes LOCK_open stalls". It's well known that persistent statistics for InnoDB …
I currently have on a MySQL 5.6 database using innodb_file_per_table the following individual tablespace file.
The schema is all InnoDB tables, and there ARE NO Full Text
Indexes. I cannot comment on if a developer has tried to create
I am none the wiser in explaining the ongoing use of these files, or if it can be/should be deleted.
On closer inspection there are infact a number of FTS files.
$ ls -al FTS* -rw-r----- 1 mysql mysql 98304 Jan 29 16:21 FTS_00000000000001bb_BEING_DELETED_CACHE.ibd -rw-r----- 1 mysql mysql 98304 Jan 29 16:20 …[Read more...]
For this year’s Percona Live: MySQL Conference and Expo 2014 (PLMCE), Davi Arnaut and I submitted a couple of co-speaking sessions proposals, both of which were accepted. Please come and see us and learn some more about InnoDB at the following sessions:
In this new installment of the series, we explore the most crucial structures for crash …[Read more...]
This is part of the ongoing work on improving the transaction life cycle management. In 5.7.2 we split the transaction list into two. The read-only transaction list and the read-write transaction list. There was another "virtual" list, the auto-commit non-locking read-only (AC-NL-RO) transaction list. The change in 5.7.2 was that by default a transaction was treated as read only and added to the read-only transaction list. Only when it was determined that the transaction was going to do an update we removed the transaction from the read-only list and moved it to the read-write transaction list. This initial add to the the read-only list forced …[Read more...]
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Uma das mais importantes configurações para quem usa InnoDB é o innodb_buffer_pool_size, ele basicamente armazena dados e índices em memória, quando o MySQL recebe uma query e as paginas que contem o resultado da pesquisa/índice estao armazenadas no buffer, o MySQL não precisar ler essas informações do disco, o que é muito mais rápido (velocidade da memória vs velocidade do disco) .
Como estas informações estão armazenadas na memória, cada vez que o MySQL é re-iniciado, o buffer é apagado, e para “esquentar” o buffer normalmente leva-se algum tempo.
Para agilizar …[Read more...]
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As we know, one of the most important config for InnoDB is the innodb_buffer_pool_size, it basically store the innodb data and indexes in memory, when MySQL receives a query and the InnoDB pages involved on that query are stored in the buffer, it does not need to go to the disk to return the result, which is much faster (memory speed vs disk speed).
As it is stored in memory, every time you restart your MySQL
server it starts with a clean/empty buffer pool and usually it
take some time to warm-up the buffer.
To speed up this process, we can configure 2 variables that will dump and reload the …
This is part of the ongoing work on improving the transaction life cycle management. In 5.7.2 we split the transaction list into two. The read-only transaction list and the read-write transaction list. There was another “virtual” list, the auto-commit non-locking read-only (AC-NL-RO) transaction list. The change in 5.7.2 was that by default a transaction was treated as read only and added to the read-only transaction list. Only when it was determined that the transaction was going to do an update we removed the transaction from the read-only list and moved it to the read-write transaction list. This initial add to the the read-only list forced the …[Read more...]
InnoDB Fulltext Search now supports plugin parser in MySQL 5.7.3 release. It is a compatible feature as for MyISAM Fulltext Search. So the syntax and usage remain to be largely the same.
A parser plugin can operate in either of two roles:
a) The plugin can replace the built-in parser. In this role, the plugin reads the input to be parsed, splits it up into words, and passes the words to the server (either for indexing or for word accumulation).
b) The plugin can act in conjunction with the built-in parser by serving as a front end for it. In this role, the plugin extracts text from the input and passes the text to the parser, …[Read more...]