Archive for performance

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Oracle performance tuning - an update

Oracle performance tuning – an update

A tutorial is now available to perform Oracle performance tuning of applications and SQL statements. This tutorial has been expanded to include case studies, which will go a long way in better understanding of concepts explained. Link to the PDF tutorial here: Tuning.pdf This current posting is an extension to the existing post on performance [...]

Oracle: Snapshot too old?

Oracle: Snapshot too old?

Okay, so you have received the Oracle error ORA-01555 Snapshot Too Old and have no clue how to go about resolving it? This post is made for you then. (The first time an application developer has written about this rather than a DBA.) First, why does this occur? When you run a query, Oracle retains [...]

Performance tuning tips

Performance tuning tips

Today I will share with you a couple of tips on process performance tuning: rewriting your code to be faster. This, for a change (contrasted with my previous posts on performance tuning), has nothing to do with Oracle or SQL: you can use these tips in any language. When your code has been identified as [...]

Top 10 considerations when preparing a software test plan

Top 10 considerations when preparing a software test plan

Click on images to enlarge -> Test the parts of the application that have changed since the last cycle / go live This part of the test plan is very obvious: test the changes to the application. Each change needs to be tested individually if possible, or as groups if the number of changes is [...]

When NOT to normalise the database

When NOT to normalise the database

When talking of Database Normalisation, textbooks often talk of BCNF, fifth and higher normal forms. However, in practice (in large software/ERPs) I have rarely noticed normalisation beyond Third Normal form. In fact, there is a certain degree of redundancy that is desirable. While doing database design, I believe there are two critical aspects that should [...]

Performance tuning SQL queries in Oracle

Performance tuning SQL queries in Oracle

Video tutorial showing how to optimise your SQL queries for maximum performance. Talks about indexes, statistics, hints and optimiser plans.