Today when I was studying for the MySQL 5.6 exams.
I was studying for these two items:
The first step is to create a table, partition it with a hash.
mysql> CREATE TABLE pfoo (id INT AUTO_INCREMENT PRIMARY KEY, name VARCHAR(255))[Read more...]
-> PARTITION BY HASH(id) PARTITIONS 4;
Query OK, 0 rows affected (0.04 sec)
mysql> INSERT INTO pfoo(name) VALUES('test01'),('test02'),('test03'),('test04'),
At MySQL Connect 2013, I talked about how we used MySQL 5.6 at
Facebook, and explained some of new features we added to our
Facebook MySQL 5.6 source tree. In this post, I'm
going to talk about how we made full table scan faster in
Faster full table scan in InnoDB In general, almost all queries from applications are using indexes, and reading very few rows (0..1 on primary key lookups and 0..hundreds on range scans). But sometimes we run full table scans. Typical full table scan examples are logical backups (mysqldump) and online schema …
Today as i was learning for the new MySQL 5.6-certification (more about that in a later post) i stumbled again across the host_cache-Table that was added to MySQL in 5.6.5. Before that you had no chance to check which hosts are already known by the MySQL-server.
So thats a pretty good feature for us. And even better: you could resize the size of the host_cache now! Whoohoo, awesome! As we have a lot of servers that need to connect to one of our MySQL-server and we could not switch to ip-based-authentication we were really happy to tune the host_cache-size without recompiling MySQL.
Unfortunately i noticed that the …[Read more...]
I checked some updates to Shard-Query into SVN. Partitioning support has been extended for MySQL 5.6+ to ALL partitioning types.
This includes all previously unsupported types including RANGE LIST/COLUMNS partitioned tables that are partitioned over more than one column, and HASH/KEY/LINEAR variants as well. Shard-Query now exclusively uses the PARTITION hint for partition elimination instead of WHERE clauses in MySQL 5.6. For 5.5 and previous versions, support remains limited to LIST,RANGE, and LIST/RANGE COLUMNS over a single column.
The old mysql interface DAL has been replaced completely by the PDO DAL.
There is no major …[Read more...]
Yet another user installed MySQL 5.5.32 yesterday and got a
system that can not start... It's really easy to help in this
case - just downgrade back to 5.5.31 or upgrade to 5.5.33 if you
can. Why problem happened during upgrade? Because of a regression
This case that was easily solved during a quick chat reminded me about the problem of bugs in production. Nobody expects any sane DBA to review every new bug report, but some of them should not be missed, at least when upgrading to any newer version. Regression bugs (I see 15 …
Notable contribution of MySQL Community to MySQL 5.6.13 was
explicitly recognized recently. But users and
contributors still continue their efforts, as well as Oracle
engineers. Even though MySQL 5.6.13 has been generally available
just for few days, we already have several new bug reports and
updates to known bugs at http://bugs.mysql.com. Let me present a short list
with some comments.
I feel like MySQL 5.6.12 was released ages ago, while in reality
it was on June 3, less than 2 months ago. No wonder I feel so,
after writing several posts about bugs fixed and not fixed in
it... Anyway, we still have to wait for MySQL 5.6.13 for a week
or even two probably and in the meantime I decided to write new
post for this series based on good old idea of making a digest of
my recent bugs-related posts at Facebook. I know, it's boring and annoying (same
as waiting for the release of 5.6.13).
Let's start with …
MySQL 5.6 has many new features and some of them change usual DBA
procedures and formerly well known facts/limitations. It's
important to have all these properly documented now, when MySQL
5.6 is GA for 6 months already and is supposed to be widely used
in production. So, I think it's time to check what documentation
problems still remain.
Here is the list of active bug reports in Server: Docs category for version 5.6, starting with recently reported:
Let me present a quick review of new and recently verified MySQL
bug reports (mostly in 5.6.12, but not only). Surely I have to
start with this request that many my colleagues had already
mentioned in their blogs:
Bug #69558 - Put *all* know bugs into the public bug tracking system at bugs.mysql.com. We may argue on how and when this should apply to "security" bugs, but automatic bi-directional replication (even if delayed) with Oracle internals bugs database is what I was also asking for since we were forced to use it. Click on "Affects Me" button there and …