When a specific query in Oracle runs unusually slow, systematic diagnostics can help identify the root cause. Below is a step-by-step methodology to troubleshoot and optimize the query effectively. 1. Check the Execution Plan (Explain Plan) Use EXPLAIN PLAN FOR or DBMS_XPLAN.DISPLAY_CURSOR to examine how Oracle is executing the query. EXPLAIN PLAN FOR<your-query>;SELECT * FROM […]
When an application team approaches you with a complaint of performance degradation on an Oracle Database, a structured and methodical troubleshooting approach is paramount. Below is a strategic, end-to-end diagnostic framework to identify and remediate the root cause: Step 1: Preliminary Assessment – Framing the Problem Before diving into deep diagnostics, it’s imperative to clearly […]
Sequences are a fundamental feature in Oracle databases, commonly used for generating unique identifiers such as primary keys. However, in a Real Application Clusters (RAC) environment, sequence behavior introduces certain performance and ordering challenges that require careful configuration. This blog provides insights into sequence configurations, gaps, and their performance impact in a RAC setup. 1. […]
An SQL Profile in Oracle is a set of optimizer directives created to improve the execution plan for a specific SQL statement. It contains statistical information or corrections to cardinality and cost estimates, allowing the optimizer to generate a more efficient plan without changing the SQL code itself. SQL Profiles are typically generated by the […]