Sample code for 6th edition of Oracle PL/SQL Programming

O'Reilly Media published the 6th edition of my favorite book in the whole world:

Oracle PL/SQL Programming

It's my favorite because it has had more (and more positive) impact on my life than any other book I've ever written or read.

Fortunately, lots of other people like it, too.

To make it as useful as possible, we include lots of scripts demonstrating features of PL/SQL.

You can access those scripts by going to the above link and clicking on Download Example Code or click here for the direct link.

Comments

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...

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, ...

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...

Obsessed with Oracle PL/SQL

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