Tag Archives: dba

mysql becomes mariadb

fedora and opensuse will be replacing mysql with mariadb

mysql uuid gotchas

http://dev.mysql.com/doc/refman/5.1/en/miscellaneous-functions.html#function_uuid

mysql uuid gotchas

  • Two calls to UUID() are expected to generate two different values, even if these calls are performed on two separate computers that are not connected to each other.
  • The fifth number is an IEEE 802 node number that provides spatial uniqueness. A random number is substituted if the latter is not available (for example, because the host computer has no Ethernet card, or we do not know how to find the hardware address of an interface on your operating system). In this case, spatial uniqueness cannot be guaranteed. Nevertheless, a collision should have very low probability.
  • Although UUID() values are intended to be unique, they are not necessarily unguessable or unpredictable. If unpredictability is required, UUID values should be generated some other way.

theres more to stacks than overflows

i’ve been finding quite a few answers to recent technical problems and questions on stackoverflow.com but what i hadnt realised is that there’s more to stack than just overflow ! it turns out that stackexchange.com that owns and runs stackoverflow also runs 68 other Q&A sites including:

all of which are moderated using their theory-of-moderation

oracle 5u6 and phpmyadmin

the oracle 5u6 repos seems to missing  php-mcrypt so you can’t directly install and run phpmyadmin !

what i had to do was

and then

  • edit /etc/httpd/conf.d/phpmyadmin.conf to allow my IP
  • service httpd reload

Easy Eclipse for LAMP Web Developers IDE

Easy Eclipse for LAMP which is fully multi-platform compatible including GNU/Linux & Apple Mac OS X now has add-ons, extensions, plug-ins for :

and you can find even more Easy Eclipse plug-ins @

to make it one of the best free libre open source IDEs for LAMP web developers !

Read and post comments | Send to a friend

jTDS open source JDBC 3.0 driver for MS SQL Server and Sybase

jTDS is an open source 100% pure Java (type 4) JDBC 3.0 driver for MS SQL Server (6.5, 7, 2000 and 2005) and Sybase (10, 11, 12, 15). jTDS is based on FreeTDS and is currently the fastest production-ready JDBC driver for MS SQL Server and Sybase.

jTDS is 100% JDBC 3.0 compatible, supporting forward-only and scrollable/updateable ResultSets, concurrent (completely independent) Statements and implementing all the DatabaseMetaData and ResultSetMetaData methods.

jTDS is used in a number of commercial applications. It has been tested with and is actually recommended as the driver to use for MS SQL Server by pretty much all open source AND commercial database management tools:

There are quite a few database management tools that come bundled together with jTDS:

Read and post comments | Send to a friend

Oracle Database 10g Express Edition (Oracle Database XE)

If you are looking for an alternative database system have a look at

http://www.oracle.com/pls/xe102/homepage

Oracle Database 10g Express Edition (Oracle Database XE) is a free-of-charge version of the world's most capable relational database. Oracle Database XE is easy to install, easy to manage, and easy to develop with.

With Oracle Database XE, you use an intuitive, browser-based interface, to:

  • Administer the database
  • Create tables, views, and other database objects
  • Import, export, and view table data
  • Run queries and SQL scripts
  • Generate reports

http://www.oracle.com/pls/xe102/homepage

Read and post comments | Send to a friend

Oracle and Open Source

MySQL UTF-8, backslashes ‘ ’ & singlequotes ‘ ‘ ’

1)  
watch out for the additional Unicode single quote characters u2018 ( ‘ ) & u2019 ( ’ )

2)
use '\' when inserting '' and
use '\\' for looking for '' in LIKE statements !

3a)
watch out for LIKE <> REGEXP !

3b)
where
 first_name LIKE '%\\%' or  
 last_name LIKE '%\\%' or
 email LIKE '%\\%'

3c)
where
 first_name REGEXP '.*\\.*' or  
 last_name REGEXP '.*\\.*' or
 email REGEXP '.*\\.*'

4)
documentation

http://dev.mysql.com/doc/refman/5.0/en/string-comparison-functions.html#operator_like

extract
 
because MySQL uses C escape syntax in strings (for example, u2018nu2019 to represent a newline character), you must double any u2018\u2019 that you use in LIKE strings. For example, to search for u2018nu2019, specify it as u2018\nu2019. To search for u2018\u2019, specify it as u2018\\u2019; this is because the backslashes are stripped once by the parser and again when the pattern match is made, leaving a single backslash to be matched against.

ANY FINALLY FINALLY !

(Exception: At the end of the pattern string, backslash can be specified as u2018\u2019. At the end of the string, backslash stands for itself because there is nothing following to escape.)

Read and post comments | Send to a friend