Monday, July 18, 2011

Quick guide to recent PL/SQL Challenge quizzes

For those of you who have not yet started visiting the PL/SQL Challenge website regularly, I thought I'd offer this guide to recent quizzes.

Oracle PL/SQL Quizzes

In the past week (11 July - 16 July), 972 Oracle technologists were busy answering quizzes and exploring the library of past quizzes.

Played on 11 July 2011: When a cursor is opened, Oracle identifies the set of data that satisfies the query. As long as that cursor remains open, that dataset is not affected by any changes that are made (committed or not) to the tables from which that data is retrieved.

Played on 12 July 2011: When working with nested tables and varrays, you must initialize the collection and extend the collection to make room for elements in the collection. Under some circumstances, however, Oracle will automatically extend the collection for you.

Played on 13 July 2011: Use INITCAP and NLS_INITCAP to easily convert a string so that the first letter of each new word (alphanumerics separated by "white space") is upper-cased.

Played on 14 July 2011: Use the LIMIT clause with FETCH BULK COLLECT to place an upper limit on the number of rows retrieved (and therefore PGA memory consumed) with each fetch.

Played on 15 July 2011: You can define functions to execute in parallel, as part of a parallel query. This can be accomplished with an explicit PARALLEL_ENABLE clause in the function header. Oracle can also implicitly determine that a schema-level function can be executed in parallel.

We also recently started up APEX and SQL quizzes in July.....

Oracle Application Express Quizzes

Played on 2 July 2011: It is possible to make an alternative report the initial settting for the Interactive Report page in several ways. What you see in the Interactive Report can also be changed through the url.

Played on 9 July 2011: The developer must be careful regarding timing when referencing session state.

SQL Quizzes

Played on 2 July 2011: Use the ALL comparison condition to easily apply a WHERE clause predicate to a set of values or a subquery.

Played on 9 July 2011: Beginning in version 11 select statements support the PIVOT clause for easy pivoting of result sets.

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