If you are not familiar with tablespaces you may be wondering
what the big deal about them is. Tablespaces are a logical
addition to a database that helps maintenance, and potentially,
can improve performance.
In Oracle and MySQL, a tablespace is a logical unit meant to
store segments (i.e. tables and indexes). In Postgres, a
tablespace is a physical unit. It is a symbolic link to a
directory. Postgres does not allow tablespaces on operating
systems that do not support symbolic links (such as
windows).
The data file is the actual physical storage mechanism in Oracle
and MySQL. Postgres stores tables in individual files. Postgres
support of tablespaces is minimal. In MySQL and Oracle,
performance can be improved by a more granular spread of data
across disks. Ease of maintenance is maintained due to the
logical grouping of tablespaces.
Oracle syntax for creating a tablespace is much the same as MySQL …
MySQL has a quite unique feature: the pluggable storage engine interface. Thanks to it MySQL supports different Storage Engines for different needs: MyISAM is perfect for heavy read, InnoDB for transational data and blackhole .... for sending data to /dev/null.
Thanks to some advance science we now have a wormhole Storage Engine. While the blackhole can only be written to but nothing ever comes back, the wormhole is the inverse of it. You get data from another galaxy, but all writes might have no effect on your side. Sounds useful ?
What's the deal ? The wormhole SE is a
lua-based storage engine. The data is "stored" in a
script-language. ... Ok, this explaination doesn't help very
much. Let's take a look at an example:
The CREATE TABLE for a wormhole table is pretty
simple. No magic:
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Don Marti is bloging on Linuxworld how he thinks Qumranet has a future, just not the future they might be looking at now.
Don claims that a software project will fail if someone orders a tool to be used that he himselve is never going to use, as he will never figure out what features are important and which ones are just irrelevant. People who actually use the software should be able to decide.
He gives a good pointer to where MySQL is heading and where they came from. Typically an organisation did't decide on using MySQL after a zillion meetings an a couple of purchacing procedures before to run out to the shop and buy it. No, people just needed a working rockstable database, they took what they had available, started using it and were pretty happy about it.
That's where opensource easily gained acceptance over the past decade, but how will …
[Read more]Kevin Burton wrote recently about why SHOW SLAVE STATUS is really not a good way to monitor how far behind your replica servers are, and how replica network timeouts can mess up the replica lag. I’d like to chime in and say this is exactly why I thought Jeremy Cole’s MySQL Heartbeat script was such a natural fit for the MySQL Toolkit. It measures replica lag in a “show me the money” way: it looks for the effects of up-to-date replication, rather than asking the replica how far behind it thinks it is.
A while ago Peter Zaitsev wrote about his wishes for mysqldump. These included multi-threaded dumps and “safe” dumps that would wait for a server to restart if it crashed, then keep dumping other tables. I’ve had sketches of this done for a while, but during this week I fleshed it out while writing about backup and recovery for our upcoming book. I had my own list of features I wanted to add:
I remember the first time I downloaded MySQL. I think I was using
Mandrake Linux. Anyway, the install was fairly painless but once
it was installed, I had no clue how to run queries.
I was coming from an Oracle background and was used to SQL*Plus.
I was also familiar with PostgreSQL and psql. For the life of me,
I could not figure out how to get into MySQL.
So, for you developers and brand new users, you can easily start
MySQL and start using it. This is not meant for a production
installation, just for playing on your laptop or desktop.
Start MySQL by running mysqld (mysqld.exe on Windows). It will be
in your MySQL home/bin directory. That gets the server portion of
our program running.
The SQL*Plus equivalent is mysql (or mysql.exe). If you are
logging in for the first time, you can use root. Once you are in,
you can create other users.
To log in and run commands, type: …
Another few weeks has passed since I started Open Query, and I
can now say I'm very pleased with incoming consulting work and
bookings for the upcoming Open Query MySQL training days in
Brisbane and Melbourne, particularly from previously unknown
sources.
(I was pondering the blog title but decided on the above - it's
not really "MySQL Training by Open Query", because I do use my
own training materials in my own short course modular
format.)
The MySQL Storage Engines training day in Brisbane
(8 October) looks like it may actually get "sold out", I do limit
the maximum number of participants to between 8 and 12 people for
any of my classes. This class is very important for any MySQL
user, whether relatively new to MySQL or very experienced, and
also for professionals who are experienced with other RDBMS. I
may not have picked the sexiest title, but it …
I just downloaded Falcon and was running some tests. I was getting an error:
C:\MySQL\bin>mysqladmin version status proc
mysqladmin: connect to server at 'localhost' failed
error: 'Access denied for user 'ODBC'@'localhost'
(using password: NO)'
To fix this error, just add a -u parameter, i.e.:
C:\MySQL\bin>mysqladmin version status proc -u root mysqladmin Ver 8.42 Distrib 6.0.2-alpha, for Win32 on ia32 Copyright (C) 2000-2006 MySQL AB This software comes with ABSOLUTELY NO WARRANTY. This is free software, and you are welcome to modify and redistribute it under the GPL license
Server version 6.0.2-alpha-community-nt-debug Protocol version 10 Connection localhost via TCP/IP TCP port 3306 Uptime: 27 min 43 sec
Threads: 1 Questions: 4 Slow queries: 0 Opens: 15 Flush tables: 1 Open tables: 8 Queries …[Read more]
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