Oracle Performance Tuning
AWR/ASH, wait events, SQL & optimizer tuning
Oracle performance work goes wrong when it starts from ratios and hunches instead of where time actually goes. The method that holds up is time-based: read DB time, rank the wait events by their share of it, and follow the top one to the SQL or the segment behind it. These guides teach that method end to end — how to read an AWR report without drowning, the half-dozen wait events that carry most real problems, and how to tell a SQL problem from a storage problem — with a free lab that reproduces each wait event on your own machine so you see the signature, not just read about it.
Guides in this pillar
- Oracle Partition Pruning: Read One Partition, Not the Whole Table
Partition pruning is the whole point of partitioning for performance: how the optimizer skips partitions it does not need, the function-on-the-key mistake that silently defeats it, static vs dynamic pruning in the plan, and a lab that reads one partition instead of twenty-four. - Oracle SQL Plan Management: Stop a Good Plan From Going Bad
How Oracle SQL plan baselines keep a good execution plan from silently regressing: what a baseline is, capturing and evolving them, and proving one holds the plan when the statistics drift. - Oracle Optimizer Statistics, Demystified
Oracle optimizer statistics without the cargo cult: histograms, extended stats for correlated columns, the automatic job, and how to keep your plans honest. - Oracle Execution Plans, Decoded: The One Number That Matters
Read an Oracle execution plan the way that finds the problem: compare E-Rows to A-Rows with DBMS_XPLAN, spot the estimate that blew up, and fix the query that is actually slow. - ORA-00060 Deadlock: Find It, Fix It, Prevent It
ORA-00060 rolls back one statement, not your transaction. How to read the deadlock graph, the causes (lock order, unindexed FKs, bitmaps, ITL), and the fixes. - Oracle Wait Events, Decoded: The Half-Dozen
A wait event is just where a session spent time not on CPU. Learn the six that matter, rank them by DB time, and ignore the idle ones. - How to Read an AWR Report Without Drowning
A field guide to Oracle AWR and ASH: DB Time as the master metric, the sections that matter, wait events decoded, the ratios to ignore — plus a free lab.