While there is quite a bit that can be done with read only
engines, writing data is entirely more fun :)
For our next lesson we are going to be doing exactly that. Unless
you are writing a blob store only engine you will need to deal
with fields, aka the columns you declare with a create table.
Placing these fields into some sort of format is required.
Different engines implement different written forms to disk. Most
transactional engines work in block formats, while stream designs
are common for engines which need high write performance.
There is no one right way to implement storage on disk, every
design has a trade off.
Let us look at XML. It is slow to parse and slow to read. XML
though is adored by many because it is a simple format that can
be ready by many applications.
For our example we are going to put together an XML engine, and
to that end we will use the …
Man, I can't believe it's been over a week since I returned from
the very great and exciting MySQL conference 2007. I got to meet
all my old and new friends. Big Kudos to Jay Pipes and all
MySQL'ers who helped make this event possible.
To me, this year's conference was the best ever. Partly because I
made the very wise decision of staying at Hyatt so I won't miss a
lot. At conferences like these the more you mingle with people,
the more you get out of it. I had some amazing conversations with
Mark Atwood, Brian Aker, Jay Pipes (I will never forget :)),
Jeremy Cole, Eric Bergen, Pascal (Yahoo! France), Beat Vontobel,
Markus Popp, Boel (MySQL HR), Christine Fortier, Marc Simony,
Govi (Amazon), the "R"s of MySQL (Ronald and Ronald), Sheeri
Kritzer, Carsten (certification), Ken Jacobs (Oracle), Kaj Arno,
Dean (MySQL Support head), Domas, Kerry Ancheta (MySQL sales guru
:)), Baron, Paul Tuckfield, Don MacAskill, Tobias, Peter Zaitsev,
Chip …
I’ve talked to several people that have questions about how alter table works under the hood. They want to know how it handles locking tables why they can sometimes use a table during alter table and other times they can’t. Also why it’s so slow
First let’s look at the basic process alter table typically goes through.
- If a transaction is open on this thread, commit it.
- Acquire a read lock for the table.
- Make a temporary table with new structure
- Copy the old table to the temporary table row by row changing the structure of the rows on the fly.
- Rename the original table out of the way
- Rename the temporary table to the original table name.
- Drop the original table.
- Release the read lock.
The slowest part of the process is copying rows from the original table to the temporary table. For large tables this can take minutes …
[Read more]Yes, I know there are a lot of software development "top n" lists out there, and many dealing with writing "-[i/a]ble" software (extensible, maintainable, saleable, etc), but personally I wanted to get these concepts that have been rattling around in my brain for sometime down somewhere and hopefully start a discussion around them. Even though this isn't a wiki, I'll probably end up treating this like a living document myself.
For a long time (in software years), I've been maintaining the code base for the JDBC driver for MySQL. I also work very closely with the support team on various connectivity-related issues (JDBC, ODBC, ADO.Net, P-this-or-that, etc.) that our customers have, and have had the (mis)fortune of debugging all kinds of problems in various stacks over the years.
Sometimes we (MySQL) make debugging more of a problem than it needs to be, and sometimes it's just inherent problems in the "stack". Given that I …
[Read more]Yes, I know there are a lot of software development "top n" lists out there, and many dealing with writing "-[i/a]ble" software (extensible, maintainable, saleable, etc), but personally I wanted to get these concepts that have been rattling around in my brain for sometime down somewhere and hopefully start a discussion around them. Even though this isn't a wiki, I'll probably end up treating this like a living document myself.
For a long time (in software years), I've been maintaining the code base for the JDBC driver for MySQL. I also work very closely with the support team on various connectivity-related issues (JDBC, ODBC, ADO.Net, P-this-or-that, etc.) that our customers have, and have had the (mis)fortune of debugging all kinds of problems in various stacks over the years.
Sometimes we (MySQL) make debugging more of a problem than it needs to be, and sometimes it's just inherent problems in the "stack". Given that I …
[Read more]Yes, I know there are a lot of software development "top n" lists out there, and many dealing with writing "-[i/a]ble" software (extensible, maintainable, saleable, etc), but personally I wanted to get these concepts that have been rattling around in my brain for sometime down somewhere and hopefully start a discussion around them. Even though this isn't a wiki, I'll probably end up treating this like a living document myself.
For a long time (in software years), I've been maintaining the code base for the JDBC driver for MySQL. I also work very closely with the support team on various connectivity-related issues (JDBC, ODBC, ADO.Net, P-this-or-that, etc.) that our customers have, and have had the (mis)fortune of debugging all kinds of problems in various stacks over the years.
Sometimes we (MySQL) make debugging more of a problem than it needs to be, and sometimes it's just inherent problems in the "stack". Given that I …
[Read more]
this time it only took two months since the last release
? mysql connector/odbc 3.51.15 is now available.
there aren?t a lot of bugs fixed in this release, compared to the
150 or so open bugs, but it is nice when you get
to close a bug that is nearly three years old.
i?m not sure when the next release will happen, but i already
have one
patch pending.
By Mike Hendrickson
Tim has asked me to take over writing the quarterly report on the state of the computer book market.
As described in the post Computer Book Sales as a Technology Trend Indicator, our research group has built a MySQL datamart containing Bookscan's weekly top 10,000 titles sold. Bookscan measures actual cash register sales in bookstores to you, the individuals purchasing and reading the books. Retailers such as Borders, Barnes & Noble, and Amazon make up the lion's share of these sales.
Book Market Performance
Here's the year-on-year trend for the entire computer book market since 2003, when we …
[Read more]
It is a good practice to check the integrity of your backups from
time to time. You don't want something like this happening to you
:)
time gunzip -f -v entrieva/db4/guestbook_M-070507.tar.gz
entrieva/db4/guestbook_M-070507.tar.gz:
gunzip: entrieva/db4/guestbook_M-070507.tar.gz: unexpected end of file
real 67m56.782s
user 48m40.006s
sys 14m14.584s
Earlier, I blogged about how to install Solaris 10 on Mac book using Parallels. This post contains links to screen casts about installing Open Solaris on a laptop as dual boot.
[Read more]