This is fun. Probably submitting a bug report if I can get to the
bottom of it.
Stupid pet trick with mysql 4.0:
mysqldump [equivalent of --opt without the --add-locks]
--single-transaction --master-data | whatever
According to the manual, you'd expect this to work like it does
on mysql 4.1+. A tiny lock to grab the master data info, then a
consistent read is done via a transaction.
What actually happens? Full table lock, AND a transaction!
Delicious.
Looking inside the 4.0 source code for mysqldump.c, it's obvious
what the bug is. There's a check to exclude --single-transaction
and --lock-tables, but --master-data enables --first-slave (later
renamed to --lock-all-tables) silently, which does a lock on all
tables.
Fun! So where's the bug, right? 4.0 is deprecated. Nah, the bug
comes more recently.
See MySQL 5.0.24a. Attempt to use its …
Judges rules for Novell in SCO case. XenSource updates XenEnterprise. Red Hat releases Eclipse-based IDE for JBoss. (and more)
XenSource Raises the Bar on Enterprise-Class Virtualization with Industry?s Most Open, Scalable, High Performance Solution, XenSource (Press Release)
Red Hat Accelerates Application Development and Migration with Integrated Developer Tools, Red Hat (Press Release)
Actuate Harnesses Open Source to Advance Leadership in BI, Actuate (Press Release)
Fonality Launches Free Business Phone System with Free Worldwide …
[Read more]It’s very nice that the LOAD XML patch finally got some attention. I wasn’t expecting it anymore. I worked on this with Erik a year ago. My C programming skill were to rusty at that time, that only my BNF code contribution was used and a lot of issues were never solved. With my C prog skills back up to a decent level, I;m planning to pick up the project. Now seems to be a better time than ever.
The current solution works well in certain situations, but definitely not in all. To insert referential data, you need to specify the id value at forehand, look at project_id in the example. That …
[Read more]
Dear Lazyweb,
I have all my old .netscape and .mozilla directories for all my
past installations of Netscape, Mozilla, and Firebox, going back
to 1996. I've got cert.db, cert5.db, and cert7.db files.
I want to extract out all of the certs and keys that I had added
to those databases, and then import them into my current
~/.mozilla database.
Reading the docs and futzing around with NSS signtool, certutil,
and pk12util isn't getting me very far.
Surely there is a tool or technique do doing this...
As we started to make the switch to MySQL, several of our managers and developers (and I) assumed we’d use clustering to improve availability and performance. (Performance, because they thought we’d be able to spread our load among clustered servers.)
I read up on storage engines and got to explain more than once that we couldn’t use clustering, much to their surprise and initial disbelief.
Clustering relies on a particular database engine (NDB) that is currently an in-memory-only engine. (Ie, all your data has to fit in memory.) Since our database is much bigger than our RAM, we couldn’t use it. (Future versions promise to allow data stored on disk.) We ended up using the InnoDB storage engine, and replication for availability and performance.
So what is a storage engine? If you don’t know, you need to find out before moving to MySQL.
MySQL implements a sort of data-handling architecture, into which …
[Read more]
I pulled the latest 5.1BK sources today and built mysqld. I must
admit, it fared pretty well against my little charset tester. 0
failures and over 120 tests done which took >5 hours.
To give a clue to the score last time I run the same tests, here
are the bugs I opened!
-
-
load data infile into table with big5 chinese
fulltext index hangs 100% cpu
-
corruption with character set macce collate
macce_bin
-
myisam corruption with character set cp932 collate
cp932_japanese_ci
-
repeatable myisam fulltext index
corruption
…
Gotcha: Bug #29838
The bug itself seems so simple to repeat. I'm boggling how it was
not seen before. :-0 I really tried too many overly-complex
tests, IMHO. Sometimes, it's still best to keep it simple!
I got news from the MySQL people that my LOAD XML contribution is
added to release 5.2. Check the manual page.
The aim of the contribution is to simplify reading of XML data
into a MySQL database. The LOAD XML command supports three
different xml formats:
- field values as attributes
- field values as tags
- the format produced by the mysql -x command, with the field
name as an attribute and field value as a tag
If the LOAD XML command finds a matching field in the target
table, the value is inserted, otherwise it is ignored. If you
have used the LOAD DATA command (most of us have) you should
recognize much of the functionality, LOAD XML works much the same
way.
Zack Urlocker wrote an article today on InfoWorld titled Serving Two Markets where he comments on Matt Asay’s The open-source community’s double standard on MySQL (which is a piece of work itself) and says:
Part of the issue is that often discussions about the business of open source is seen as a “zero sum game” between community users and paying customers, meaning that in order for one group to benefit, the other group must lose. To me this polarizes the discussion in an unhealthy way.
I have to admit, I haven’t seen it that way at all. And I don’t see why anyone would. When RedHat split into …
[Read more]A