This guide walks through Oracle's memory architecture, explains SGA and PGA components, details essential memory parameters with recommended values, and provides step‑by‑step SQL checks to diagnose and tune performance on both 32‑bit and 64‑bit systems.
This article explains Oracle 12c's key memory‑related enhancements—including the extended database cache (Smart Flash Cache), PGA aggregate limit, In‑Memory column store with compression, SIMD processing, temperature‑based replacement, and big‑table cache—detailing their parameters, operation, and monitoring methods for improved database performance.
This comprehensive guide explains Oracle's memory‑management evolution, compares manual SGA/PGA sizing with ASMM, AMM and PGA automatic management, details key parameters and hidden settings, shows how to size SGA, PGA and large pages, and offers practical best‑practice recommendations for DBAs.
An Oracle RAC 11g installation on AIX failed intermittent queries with ORA‑04030 errors, and a deep dive revealed that missing shell limits for the grid user capped process memory at 128 MB, causing PGA allocation failures despite ample system resources.
