How One SQL Crashed a Core System for 12 Hours – Oracle Performance Troubleshooting

A single runaway SQL caused a 12‑hour outage of a core Oracle system; the article walks through the fault symptoms, AWR and ASH analysis, abnormal SQL identification, execution‑plan changes caused by partition operations, and the step‑by‑step remediation that restored performance.

AWRDirect Path ReadOracle

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How One SQL Crashed a Core System for 12 Hours – Oracle Performance Troubleshooting

ITPUB

Jun 29, 2016 · Databases

Why Oracle 11g Uses Direct Path Reads for Full Table Scans and How to Tune Them

The article explains how Oracle 11g may bypass the buffer cache with direct path reads during full table scans, lists common causes such as large sorts, hash joins, and parallel queries, and shows how hidden parameters like _serial_direct_read can be adjusted to improve performance.

10g11gDirect Path Read

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Why Oracle 11g Uses Direct Path Reads for Full Table Scans and How to Tune Them