When you prepare reports, you often need numbers at different levels: detailed rows, subtotals, and a grand total. Without GROUPING SETS, you would write multiple queries and stitch them together with UNION ALL. With GROUPING SETS, one query does it all — more readable, more efficient. Let’s explore this using the HR schema tables (employees, […]
In Oracle Database, temporary tablespaces play a critical role during SQL execution. Whenever a query involves sorting, joining, aggregation, index creation, or operations that cannot be handled entirely in memory (PGA), Oracle uses temporary tablespaces to store intermediate results. As a DBA, understanding how to monitor and troubleshoot temporary tablespace usage is essential to avoid […]
In high-throughput Oracle environments, cursor sharing is a pivotal lever for controlling hard parse overhead, shared pool pressure, and overall scalability. The central control is the initialization parameter CURSOR_SHARING: This article illustrates not just how cursor sharing behaves, but how to monitor it rigorously using Oracle’s dynamic performance views. 1) Environment and Safety First Run […]
In the silent architecture of the Oracle Database, every line of PL/SQL code carries weight. Performance issues arise not with a roar, but with a whisper—a process that once danced now stumbles, and somewhere deep in the code, time leaks away. As Oracle professionals, our calling is to seek out these shadows and bring them […]