Skip to main content

Planning for trouble: comments on my latest Oracle Magazine article.

In my November/December 2014 article for Oracle Magazine, Planning for Trouble, I urge developers to realize that regardless of best intentions, not everything related to our apps is under our control, and we need to assume that trouble might be coming our way.

I received today, the following comments from Gary Malandro, which I thought you might enjoy reading:

 Enjoyed your article in Oracle Magazine, and I have a few comments.

1.       You mentioned “Documents that spell out naming conventions…fit very nicely inside desk drawers”.  On our team, we have a number of policies that include the requirements for a technical design document, a software change request, source control, and some regarding style.  First thought upon hearing that is probably what-a-load-of-bureaucratic-nonsense.  Well, there are reasons for creating and enforcing these standards.  Compliance for one.  Another is we had code going into production systems that performed poorly, contained logic errors, was difficult to understand, already existed, no exception handling, etc.  With standards, we are able to peer review designs and code to make sure it is understood.  These are necessary when doing reviews otherwise it is a matter of style between developers – what 1 developer thinks is cool another finds difficult to understand.  Anyway, since we’ve implemented these policies our defect rate to test and error rate to production has improved considerably.  Besides PLSQL, we also develop in Java and .Net.  I’ve heard all the excuses as to the evil of standards and documentation (and probably said them many times myself), but the people who say this typically have to rework their code multiple times.  So pay now or pay later. 

2.       In my previous role I was supporting/developing a large volume of PL/SQL code.  I created a separate package (XXSA_DEBUG) which contained procedures to output data in various ways (a very, very, very poor man’s log4j).  In procedures I would include a way to get a debug variable and could either decide to call the output package, or just directly call it and let it decide where/how to output.   Production access is limited, so being able to change the debug flag using an application, or even running with a stub program, greatly aided when troubleshooting was required.

3.       Another thing we enforce is exception handling with clear messages.  If it’s something going to a log file or table (aimed for the developer) it should contain the procedure name and where the error occurred.  This allows any developer to trace where the error occurred.  Too many times we had log files loaded with “Failed”, and no explanation.  And thousands of lines of code that contained “Failed” for the output message. 

Thanks, Gary, for taking the time to share your experience. I would be very happy to hear from others!

Comments

  1. UnknownDecember 6, 2014 at 1:19 AM

    its really nice and awesome story i visited..so nice informative ,thanks for sharing for this Chicago Public Relations

    ReplyDelete

Post a Comment

Popular posts from this blog

Running out of PGA memory with MULTISET ops? Watch out for DISTINCT!

A PL/SQL team inside Oracle made excellent use of nested tables and MULTISET operators in SQL, blending data in tables with procedurally-generated datasets (nested tables).  All was going well when they hit the dreaded: ORA-04030: out of process memory when trying to allocate 2032 bytes  They asked for my help.  The error occurred on this SELECT: SELECT  *    FROM header_tab trx    WHERE (generated_ntab1 SUBMULTISET OF trx.column_ntab)       AND ((trx.column_ntab MULTISET             EXCEPT DISTINCT generated_ntab2) IS EMPTY) The problem is clearly related to the use of those nested tables. Now, there was clearly sufficient PGA for the nested tables themselves. So the problem was in executing the MULTISET-related functionality. We talked for a bit about dropping the use of nested tables and instead doing everything in SQL, to avoid the PGA error. That would, however require lots of wo...
4 comments
Read more

How to Pick the Limit for BULK COLLECT

This question rolled into my In Box today: In the case of using the LIMIT clause of BULK COLLECT, how do we decide what value to use for the limit? First I give the quick answer, then I provide support for that answer Quick Answer Start with 100. That's the default (and only) setting for cursor FOR loop optimizations. It offers a sweet spot of improved performance over row-by-row and not-too-much PGA memory consumption. Test to see if that's fast enough (likely will be for many cases). If not, try higher values until you reach the performance level you need - and you are not consuming too much PGA memory.  Don't hard-code the limit value: make it a parameter to your subprogram or a constant in a package specification. Don't put anything in the collection you don't need. [from Giulio Dottorini] Remember: each session that runs this code will use that amount of memory. Background When you use BULK COLLECT, you retrieve more than row with each fetch, ...
4 comments
Read more

PL/SQL 101: Save your source code to files

PL/SQL is a database programming language. This means that your source code is compiled into  and executed from within the Oracle Database. There are many fantastic consequences of this fact, many of which are explored in Bryn Llewellyn's Why Use PL/SQL? whitepaper. But this also can mean that developers see the database as the natural repository for the original source code , and this is a bad mistake to make. It's not the sort of mistake any JavaScript or Java or php developer would ever make, because that code is not compiled into the database (well, you can  compile Java into the database, but that's not where 99.99% of all Java code lives). But it's a mistake that apparently too many Oracle Database developers make. So here's the bottom line: Store each PL/SQL program unit in its own file . Use a source code control system to manage those files. Compile them into the database as needed for development and testing. In other words: you should never kee...
16 comments
Read more