cleanPath executable ready

An executable version of cleanPath is now available here!

You do need .NET Framework 2.0 to run this. It's pretty painless to download and install. You don't need IronPython.

Thanks to the newest IronPython release for making this possible! When I run

ironpythonconsole cleanPath.py

, the code runs, and it also generates cleanPath.exe without even being asked to. Until now, though, that .exe didn't actually work. In IronPython 1.0 Beta 2, however, released just Wednesday, it works great! I do need to put IronPython.dll in my directory before I compile... other than that, it's so simple, even a DBA can do it.

cleanPath.py: an IronPython utility

During my CodeCamp presentation, I introduced a very sketchy (and logically flawed) script to examine a PATH environment variable and clean out unwanted elements.

Since then, I created a much-improved version in IronPython which, I think, is actually worth using. Features:

• Conveniently view and delete path items
• Nonexistent directories and duplicate items are flagged, and can be purged with one keystroke
• works on PATH, CLASSPATH, PYTHONPATH, PERL5LIB, etc.

It's Windows-only, but only Windows makes editing your PATH such a pain, anyway.

The code is here.

Right now, you need IronPython, and use "ironpythonconsole cleanPath.py" to run it. I need to figure out how to generate an .exe, since getting set up with IronPython is too much to ask just to clean up your PATH.

[EDIT: An executable is ready now. See my next blog entry.]

Smurfette syndrome

One thing about the CodeCamp, though: severe Smurfette syndrome. Maybe 10% of the attendees were women, but probably closer to 5%.

I don't think it's the CodeCamp's fault; I'm afraid they may have gotten an accurate sample of the programmers in the area, and that's the scary thought. Possibly things would have been a little better on a weekday; men might feel more comfortable in taking a day away from home duties for their professional development. Still.

I know, it's been talked to death, and there are a million theories and stuff, but... yikes. It's just scary that one year goes by after another, and the situation persists.

On the other hand, the GCOUG meeting was about half women, maybe even a majority. At a small meeting, granted, but it's still a bright spot.

Dayton-Cincinnati Code Camp review

If you missed the CodeCamp, don't miss the next one. It was great. I'm not even into .NET, but even the minority of the conference that was non-.NET was well worth my time. Plus, sampling a bit of the .NET take on a few topics was good for my general education.

I almost wish I were involved in .NET, purely for the sake of the Dayton .NET group, which has a vitality that you just don't see that much of in the Dayton area IT community (at least, in my tracks thereof.)

Anyway, a few things I learned...

• There really are Python-experienced people in the area; I'd just never found them before.
• Ruby on Rails supports Oracle. Uh-oh. It's not that I'm unwilling to learn Ruby; it sounds great, and (of course) simple to learn. It's just that I really want to use TurboGears, but it uses SQLObject, and Oracle support in SQLObject is the sword in the stone. Many have tugged, but none have completed it, and maybe I should stop waiting and just use RoR for now.
• Speaking of Ruby, never miss seeing Jim Weirich speak. I already knew that, but maybe you didn't.
• GCOUG really needs to work on getting more people involved. There were 15-20 people at Jimmy Brock's talk on Oracle Developer Tools for .NET - none of whom had more than the haziest awareness of GCOUG's existence.
• Speaking of Jimmy's talk, Oracle Developer Tools has a great and handy way to bring .NET assemblies from Visual Studio all the way into Oracle, where they can be used like stored procedures.
  So, one glorious day, this year I hope, Visual Studio will support IronPython, and I'll be able to (essentially) write my Oracle stored procedures in Python instead of PL/SQL. And choirs of angels will sing.

I'm sure I'll have more to say about the Camp as I think about it.

Presenting (with) Bruce

When I present at a meeting, I like to use plenty of live demos. I can get away with this, because I type very, very well. (I did get into IT via the secretarial pool, after all.) Still, even I get a little nervous about whether I can keep up typing speed and accuracy with the pressure of a whole audience staring at me.

Fortunately, This blog post by Andy Todd (You do read his blog, don't you?) pointed me to Bruce, a wonderful presentation tool freshly created by Richard Jones.

Bruce lets you wrap up decent-looking slides, graphics, and Python interpreter sessions all into a single presentation that scrolls smoothly along at your command. (Simply being spared the fuss of flipping between Presentation slides and a command-prompt window is a blessing.) For demos, you can pre-enter the text you want to type, then Bruce sends it to the interpreter one character at a time. You type 'dfjkasfjdska;dfsafd', but 'def plusOne(x): return x+1' appears on the screen, and the audience thinks you're a keyboard goddess.

My one disappointment in Bruce - as I understand it (I just found it, you know) - is that the wonderful interactive session can only be used with a Python session. I'll need to dig into Bruce and PyGame to verify that, and to see if it can be extended elsewhere. I dearly want to use it when I'm demonstrating SQL.

Until Bruce, incidentally, my best bet was TPP, the Text Presentation Program. I've seen presentations done with it, and it looks OK, except it's written in Ruby and has dependencies (ncurses) that need C compiling - not very practical where I am, unfortunately.

Search engines are not Zen

I decided that I should make myself a list of questions I've never been able to resolve, or that were very difficult to research, because they don't "search" well. That is, in everything from Metalink's Search bar to Google, it's hard to come up with relevant results.

For instance,

- I'm trying to use RMAN DUPLICATE, and it does indeed produce the data files on the auxiliary database, but it doesn't create a controlfile. The documentation clearly says it should. Searching on terms like RMAN DUPLICATE controlfile not generated only brings up more pages saying that it should.

- All sorts of questions like such-and-such service DOESN'T start, program WON'T run, logfile ISN'T created. Negation - "not" - is clearly a failing of a typical search. Searching for green eggs no ham will find you 10,000 pages on green eggs AND ham, with the one page on "My green eggs came without ham!" buried anonymously as result #4,312.

I'm not sure what I'll ultimately want to do with this list. But I began to wonder, more broadly, if someone out there had already started assembling issues of unsearchable questions. Ironically, Can't Find On Google is very easy to find on Google.

Dayton - Cincinnati Code Camp

Hooray! - to the Dayton .NET Developers Group for putting together the Code Camp on Jan. 21, 2006 - a whole day of community-provided seminars on a variety of programming topics. For free! I'm looking forward to it; in fact, I'm planning to present there (on Python, naturally).

If you're anywhere near southwest Ohio, come and enjoy. Better yet, come and share! Whatever cool programming tricks you have up your sleeve - come and show the rest of us!

LibraryLookup published

My article on LibraryLookup has been published in the October 2005 issue of Technology First, a tech newsletter for the Dayton area. (I'm on p. 8-9). (The print article's content ties in with this blog post)

The sixty-second version: LibraryLookup lets you query your library's catalog directly from a page of a book vendor like Amazon, looking up that particular book for you automatically with just one click. You can get it installed in your browser in, oh, about five seconds. It's really cool, not just for helping you find books, but also as an example of clever and sneaky use of JavaScript.

Why do almost all contracts and job postings specify exactly the software that they want you to use (or to have used)?

When they want to incorporate you tightly into a large project that has already gotten underway with some specific software, OK. But I think such over-specifying is also the custom in cases where that is not at all true. It's very annoying to somebody like me, who bizzarely imagines she might be able to select the best tools for her own work.

When I take my car to the mechanic, I don't say, "You must do all the work using a Sears Craftsman #3 box wrench." But maybe, if I were a writer of contracts, I would.

Announcing Dayton-Oracle mailing list

Q. How do Dayton-area users of Oracle stay in touch with one another and find out what's going on in their community?
A. They don't.

Q. Well, that's lame. What can we do about that?
A. You can sign up for the Dayton-Oracle mailing list I just set up at FreeLists.

Please spread the word!

cx_Oracle and Ubuntu

Naturally, after getting Oracle working, my next move was to get it Python-powered by installing cx_Oracle. Installation seemed to go OK, but when I tried to use it...

>>> import cx_Oracle
Traceback (most recent call last):
  File "", line 1, in ?
ImportError: libclntsh.so.10.1: cannot open shared object file: No such file or directory

which seemed odd, because

catherine@ubuntu:~$ locate libclntsh.so.10.1
/app/oracle/oracle/product/10.2.0/db_1/lib/libclntsh.so.10.1

I extrapolated a solution from an old mailing-list post by Karl Putland: I appended /app/oracle/oracle/product/10.2.0/db_1/lib to /etc/ld.so.conf and ran ldconfig.

That was the only trick - it's working fine now!

Oracle on Ubuntu

I love my new Ubuntu Linux (version 5.10). I love how easy it was to install, how it picked right up on my wireless card.

Oracle doesn't support Ubuntu, but I installed it anyway and it's doing fine. The process was tricky, though. Here's what I learned.

1. RTFM. The Installation Guide is very important, more so than when installing Oracle on Windows. It has to be the primary document you work from, and follow step-by-step. Any other advice on Oracle/Ubuntu that you may Google up is secondary. Where Red Hat and SuSE directions differ, follow the Red Hat ones.
2. This document is useful primarily for reassuring you that the error messages you get are OK.
3. Make sure the Universe is in your Synaptic repository and install these packages: gcc, make, libxp, libaio, lesstif2, lesstif2-dev, rpm, and libdb1.
4. You can't find all the packages that the install documents call for in the Ubuntu Universe. That seems to be OK; just find the ones you can.
5. The magic word is runInstaller -ignoreSysPrereqs.
6. One little misstep and you may get something broken. It took me a couple attempts. Try, try again, following that Installation Guide even more carefully.

Oracle - Python wish list

For my upcoming Oracle - Python talks at OOUG and (maybe) COLLABORATE 06, I want to write a nice Python script in realtime, before the very eyes of the audience, like a cooking show hostess would. I'm having trouble deciding on an objective for the script, though. The ideal script would make Oracle people sit up and scream, "I want that! That power must be mine!" It should also

• Be very Oracle relevant
• Be something that can't be done with SQL or PL/SQL alone
• But still use some SQL (to demonstrate cx_Oracle)
• Not duplicate the function of any existing Oracle utility or Oracle Enterprise Manager (this one worries me since I don't even know everything OEM can do)
• Be writeable within an hour (shouldn't be a problem)

I'm brainstorming for ideas, but I don't know if any of them are really "it".

• Compare parameters in INIT.ORA to live database (this is what I used for my paper)
• Condense or groom a TKPROF output file
• Populate a database table from a website (but what website? What's cool enough?)
• Find and compare TNSNAMES.ORA files scattered across filesystem. Find TNSNAMES entries that are "dead" (unpingable).
• Format alert.ora for better readability; color-code messages?
• Measure log switch frequency from alert.ora
• Find obsolete (unused) configuration files like init.ora, ORACLE_HOMEs, etc.
• Clean up PATH (mine gets cluttered with droppings from various installs/uninstalls)

Any comments on these? Anything you'd like to put on the wish list? Let your imagination run wild - what wishes would you make to a magic Oracle genie? That's the kind of "gotta have it" feeling I'd like to produce.

Ohio LinuxFest

I had a great time at Ohio LinuxFest. Highlights, in my book, were

• Jorge Castro's Ubuntu talk. He pointed us to a lot of great stuff to try out, and his enthusiasm was infectuous.
• Rich Bowen's mod_rewrite talk. I've never encountered Apache documentation that I was truly happy with, but Rich was wonderfully clear. I want his book.
• Ram Rao's virtualization talk. Xen sounds like it has jumped straight to #1 in my List of Reasons My Management Would Let Me Use Linux For The Database Server If They Had A Clue. Moving entire virtual machines easily between production and development servers, with almost no performance impact... wow, that would be incredible.
• The reception. Hey, the only thing better than dancing is dancing with geeks. Too bad I had to leave early, but somebody foolishly located Dayton too far from Columbus.

I heard that the attendance had more than doubled from the last year, and indeed, many of the people I talked to were quite new to Linux. That's the one improvement I'd suggest for the event. There were good talks for newbies, but not enough of them, nor did the schedule provide clear enough guidance to help newbies steer themselves that way.

COLLABORATE 06, featuring me, maybe

I just submitted a proposal for a technical session ("Python and Oracle: Coding that Cooks") at COLLABORATE 06, the IOUG's conference next April. Wish me luck! I'm not sure how hard it is to get a slot; I do know that the speaker quality there has been excellent for the past two years.

introducing sqlWrap.py

A Python script, for your use and suggestions.
Sorry, I know this is awfully long for a blog post - I have to figure out a better place to put it. I wonder if it would be appropriate for the Cheese Shop?

"""
sqlWrap
Adds convenience methods to DB-API2 connection objects.

Sep. 22, 2005 by Catherine Devlin (catherine.devlin@gmail.com, http://catherinedevlin.blogspot.com/)

This script is NOT intended as an object/relational mapper.
Rather, it helps experienced SQL users form their SQL more quickly.

Methods: insert, update, delete, select, genericSelect
These methods accept arguments for the WHERE, SET, etc. clauses
that should generally be provided as dictionaries; i.e.
whereClause = {'col1':'val1','col2':'val2%'} implies
  "WHERE col1 = 'val1' AND col2 LIKE 'val2%'",
setClause = {'col1':'val1'} implies 
  "SET col1 = 'val1'"
You may also pass object instances for whereClause and setClause,
with instance attributes corresponding to column names... but this 
has barely been tested!
They also automatically make use of bind variables, which have
performance and security benefits over hard-coding values in SQL.
The different ways of handling bind variables in various DB-API 
adapters are masked from the user.

Currently supports: Oracle (cx_Oracle), sqlite (pysqlite)

Sample usage:
# setup - unchanged from cx_Oracle
conn = OraConnection('scott/tiger@orcl') 
conn.cursor().execute('CREATE TABLE myTable (column1 varchar2(10), column2 varchar2(10), column3 varchar2(10))')
# now try out the sqlWrap convenience methods
conn.insert('myTable', setClause={'column1':'value1','column2':'value2'})
conn.insert('myTable', setClause={'column1':'value1a','column2':'value2a','column3':'value3a'})  
for row in conn.select(source='myTable'): 
    print row 
for row in conn.select(source='myTable', whereClause={'column1':'value1'}, resultProcessor=conn.dictionaryize):
    print row
conn.update('myTable', setClause={'column1':'value1','column2':'value2'}, whereClause={'column3':'value3'})
# as always, must explicitly commit  
conn.commit()
"""      

Get sqlWrap.py here

If you're in Ohio...

notes to self

Do not smash your head against a problem for consecutive hours. Instead:

• Ask for help. It doesn't matter whether you ever send the request; in the process of putting the problem into language, you're more than likely to solve it. (Yes, I know: "Pair programming!", you say. But I'm all alone here.)
• Stand up and walk away. Do not touch anything resembling a computer for at least ten minutes.

Will someone please remind me of these next time I get stuck?

Python for Oracle Geeks: unplugged!

I've been invited to present at the Oct. 27 Ohio Oracle User Group meeting in Columbus. Hooray! After I've practiced at a local group, I'll feel ready to start trying to get to wider areas, maybe even the national IOUG conference. I will bring tanker-trucks full of Python Kool-Aid!

We have a lot of catching up to do - Oracle's OTN has been publishing a LOT on PHP, and Oracle and Zend are providing a handy-looking integrated package. I salute the PHP folks, but I don't want that to be the only dynamic language active in Oracle-land.

sqlite: a flyswatter to kill flies

I'm now using sqlite to support an Oracle production database. I love it!

When I first went to download sqlite, I went away frustrated. I found an executable described as "A command-line program for accessing and modifying SQLite databases", and thought, "OK, so that's my SQL*Plus equivalent, but where's the actual server? The part that keeps the database process running?"

Because I have been an Oracle-only person so long, I didn't understand that sqlite doesn't need anything like that. It's simply this:

1. a single executable program that creates and modifies a database file
2. A database file

And that's it. Really! You can't imagine how dizzying and refreshing that is to someone who's spent hours before a certification exam memorizing Oracle architecture diagrams.

Anyway, there are other simple database engines, of course, but sqlite has gotten a lot of attention recently (like an Open Source Award) for its efficiency and its support across many languages. There's an excellent and honest rundown of its powers and limitations here.

So, anyway - why sqlite to support Oracle? Well, one of my Oracle instances has a bunch of logic applied to it by a nightly batch job. For every data record, a series of decisions are made, and our users ask questions like, "For record #12945, why did it decide X instead of Y last Tuesday?" And I have to be able to answer, "Well, the seventh of the nine tests conducted on that record determined that, since column 'product' was 'lutefisk' and 'quantity_kg' was 22, blah blah blah..." So all those decisions need to be logged every night.

That generates a quantity of data far outweighing the application data itself. It can be discarded after a week or two, but all that inserting and deleting was causing out-of-control generation of archive log files and making a mess of my disk space allocation. By moving that data out into a sqlite database, it becomes a single simple file that can be moved or deleted as easily as any other file.

So, thanks to sqlite, I'm living happily ever after. Hooray!