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# Month: June 2009

## New and Noteworthy in openark kit

MySQL openark kit June 30, 2009June 30, 2009

A new release of openark kit is out. Some interesting additions.changes are:

- oak-online-alter-table: now works with multicolumn UNIQUE KEYs
- New: oak-chunk-update: break an long running or non indexed UPDATE/DELETE to small chunks
- oak-purge-master-logs, oak-show-replication-status: support for non standard slave ports

openark kit is a set of utilities for MySQL, helping in easing out everyday’s work. Let’s look more closely at the changes.

#### oak-online-alter-table

The utility allows for non-blocking ALTER TABLE operations, under certain limitations. One limitation which has been removed in the current release was the single-column UNIQUE KEY limitation. As of now, a requirement for running oak-online-alter-table is that the altered table has some UNIQUE KEY. It could be numerical, textual, single column, multi-column (compound), anything. Continue reading » “New and Noteworthy in openark kit”

## Unwalking a string with GROUP_CONCAT

MySQL Books SQL June 16, 2009September 27, 2009

“Walking a string” is an SQL technique to convert a single value into multiple rows result set. For example, walking the string ‘hello’ results with 5 rows, each of which contains a single character from the text.

I’ll present a brief example of walking a string, and then show how to “unwalk” the string: do the reverse operation.

To walk a string, an integers table is required (or this could be a good use for SeqEngine): Continue reading » “Unwalking a string with GROUP_CONCAT”

## Even more on MySQL password security

MySQL Security June 8, 2009August 10, 2009

This post follows Ronald Bradford’s More Basic MySQL Security, and Lenz Grimmer’s Basic MySQL Security: Providing passwords on the command line and More on MySQL password security.

In Ronald’s post I’ve argued that passwords provided on command line are visible in plaintext on “ps aux”. Lenz has argued that this is incorrect, providing the source code to support that. Giuseppe commenting that this has been fixed since 2002. Later on, Lenz shows that passwords are visible in plaintext on OpenSolaris, Solaris and variants of BSD and SysV.

Mental note: old habits die hard; I must remember to revisit issues from time to time.

#### Centralizing

Back to the question: why use a file to store your password, and not provide it on command line?

Continue reading » “Even more on MySQL password security”