The SELECT statement is used to retrieve information from a database. Following the execution of a SELECT statement, a tabular result is held in a result table (called a result set). It allows you to select the table columns depending on a set of criteria. SELECT statements might be as straightforward as selecting a few … Read more
The previous installment of this series examined aggregate subquery removal and subquery coalescing, describing the latter as similar in some ways to an inverse for “Or Expansion” and “Join Factorization”. In this instalment, it’s time to take a closer look at Or Expansion and we’ll move on to Join Factorization in the next instalment.… Read more
The Oracle optimizer often changes the query to get better performance. In this article, Jonathan Lewis explains two more optimizations involving subqueries.… Read more
Part 1: What is testable code, why is it important, and first glimpses on practices that can help Anyone familiar with PL/SQL, the procedural language extension to Oracle SQL, knows that the code they are touching is usually business-critical, likely to be around for a long time, and may undergo many revisions in the future. … Read more
In this article, Jonathan Lewis discusses why you might want to stop the optimizer from unnesting some subqueries and how to control where the optimizer positions each subquery.… Read more
To troubleshoot poorly performing SQL in Oracle, you must understand which transformations the optimizer has made. Jonathan Lewis demonstrates several possible optimizations for one query.… Read more
Oracle has built-in functionality to analyze text. Sanil Mhatre demonstrates how to perform a sentiment analysis on data stored in a table using Oracle Text.… Read more
Oracle added several enhancements to the sequence object in version 12c, including an “identity” column feature. Jonathan Lewis explains how to work with these new features. … Read more
Oracle sequences supply unique numbers that can be used when populating tables. In this article, Jonathan Lewis explains the typical uses of Oracle sequences.… Read more
Using sequences when scaling up with Oracle RAC presents more issues with contention. In this article, Jonathan Lewis explains how to avoid the problems.… Read more
Oracle sometimes generates smaller archived redo logs than you might expect based on the size of the online redo logs. In this article, Jonathan Lewis explains how Oracle uses online redo logs and why there might be a discrepancy in the archived log size.… Read more
SQL Developer is a popular free tool for working with Oracle databases. In this article Srinivasan Suresh explains several features of SQL Developer that can make you more productive.… Read more
Oracle has been established as one of the top database systems used in enterprises throughout the world. In this article, Cynthia Dzikiti describes her career as an Oracle application developer and covers some of the benefits of Oracle.… Read more
Learning programming logic and syntax is just the beginning. In this article, David Njoku talks about how to debug and troubleshoot errors as a new developer.… Read more
Security is, or at least should be, the priority for any IT system. In this article, Cynthia Dzikiti discusses the security aspects of ERP systems and some of the techniques used to protect data.… Read more
There is often more than one way to write a query that returns the same results, but some methods may perform better than others. In this article, Ben Brumm discusses ten best practice when writing SQL code for Oracle. … Read more
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