SQL – Find the largest number in a set of alpha-numeric values

References:

The SQL:

declare @lastIntUsed int 

create table #temp (clean_number varchar(50), IntCol int) 
; with tally as (select top (100) N=ROW_NUMBER() over (order by @@spid) from sys.all_columns),
data as ( 
   select sometable.number, clean_number
   from sometable
   cross apply ( 
      select (select C + '' FROM (select N, SUBSTRING(sometable.number, N, 1) C  
          from tally
          where N<=DATALENGTH(sometable.number)) [1]
      where C between '0' and '9'
      order by N
      for xml path('')) 
   ) p (clean_number)
   where p.clean_number is not null 
) 
insert into #temp (clean_number, IntCol) 
select number, cast(clean_number as int) IntCol from data

set @lastIntUsed = (select MAX(IntCol) from #temp) 
print @lastIntUsed
drop table #temp

I couldn’t find any way to just get the max number from the CTE itself (doesn’t mean there isn’t a way), so I said screw it – I’ll just stick the results into a temp table and then I can get the max number or the min or the max number that is less than some value or whatever I want.

Faking a connection refusal

flowersandbutterfliesfromfacebooknotorigscan

Your application connects to another server to request a service. Most of the time this hums along with no problem. But once in a while the server you are attempting to connect to refuses the connection. When this happens, the phones ring off the hook.

You would like to catch this scenario before all your users get angry. So you put some monitoring in place.

To test the monitoring, you need to fake the connection refusal. This took me longer than I care to admit to figure out, but it turns out the answer is pretty simple.

Change the port number.

So say you have Axis2 software running at the port number you are connecting to. Keep your connection string as it is, except for the port number. Change the port to a number that is not running any web service software.

That will result in a java.net.ConnectException: Connection refused error.

Learning Python – make a URL request

rosetwoandbuds002 Been learning Python lately. Have done a couple of tutorials and one or two simple programs. This post will be about a simple example of how to access some real estate information that is available from a company called Trulia.

First, some links to sites that helped me figure this out:

Download Python, install, and some reference documentation: https://www.python.org/downloads/
Stackoverflow thread about making a URL request in Python: http://stackoverflow.com/questions/17301938/making-a-request-to-a-restful-api-using-python
How to make a Trulia RSS feed with your real estate search criteria: https://www.trulia.com/tools/rss/#code_block
Some free python IDEs: http://insights.dice.com/2014/09/23/look-5-free-python-editors/
I decided to go with Visual Studio for an IDE. I picked the custom installation so I could specify Python as a supported language. https://www.visualstudio.com/downloads/

The code:

#Just a little POC to retrieve some real estate information from the web
#Python 3
 
import urllib.request #for opening connections to URLs

def main():

  truliaURL = 'https://www.trulia.com/rss2/for_sale/Burbank,CA/'

  request = urllib.request.Request(truliaURL)
  response = urllib.request.urlopen(request)
  responseData = response.read().decode('utf-8')
  print(responseData)

if __name__ == "__main__":
 main()

Debugging BlazeDS Performance

raindropsonrosebud I have a server call that returns a lot of data to the client. About 80% of the elapsed time for the call is the time after the data leaves the server and before it arrives at the client.

We’re using BlazeDS to communicate between a Flex client and a Java back end.

It is crazy hard to find much information on performance tuning for BlazeDS. But these two blog posts helped me figure out how to get some statistics about the messaging between server and client – things like elapsed time, size of message, etc.

So basically what you do is, on the server side in your services-config.xml file, in the tag of your tag, you add these two tags:

 <record-message-times>true</record-message-times>
 <record-message-sizes>true</record-message-sizes>

Then on the client side, when you instantiate a new AMFChannel, you add a line like this:

applySettings(customSettings());

And add a new function called customSettings which sets the values for these same properties on the client-side.

 private function customSettings():XML {
 return <channel-definition>
 <properties>
 <record-message-times>true</record-message-times>
 <record-message-sizes>true</record-message-sizes>
 </properties>
 </channel-definition>;
 }

Doing it this way gets around the problem of them being read-only properties.

Now, upon successful completion of service calls, add this code to your result handler:

log.debug(getResource(msg, destination, operationName, elapsedTime)); var performanceDetails:MessagePerformanceUtils = new MessagePerformanceUtils(event.message); log.debug(performanceDetails.prettyPrint());

More information on MessagePerformanceUtils here: http://help.adobe.com/en_US/FlashPlatform/reference/actionscript/3/mx/messaging/messages/MessagePerformanceUtils.html#methodSummary

What this does is get you a bunch of information to help with figuring out why the call is taking so long.

Original message size(B): 1685
Response message size(B): 6987918
Total time (s): 8.402
Network Roundtrip time (s): 3.584
Server processing time (s): 4.818
Server adapter time (s): 3.708
Server non-adapter time (s): 1.11

Don’t leave this in your production code. You’re trying to improve performance, not make it worse!