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Where to begin with Oracle and SQL
Seeing more and more questions on “where do I start with Oracle if I want to be a DBA?” My perspective is a bit off since I’ve been surrounded by Oracle for over 20 years. I hardly remember what it...
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Oracle CPU Time
Image from Bertrand Drouvot UPDATE: thanks to a discussion in the comments it’s come to my attention that there should be some more clarification on values used and what the mean at the beginning...
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CURSOR_SHARING : a picture is worth a 1000 words
Anyone who has been around Oracle performance over the years knows the grief that hard parsing SQL queries can cause on highly concurrent applications. The number one reason for hard parsing has been...
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Oracle I/O latency monitoring
One thing that I have found sorely missing in the performance pages of Enterprise Manager is latency values for various types of I/O. The performance page or top activity may show high I/O waits but...
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Metrics vs Statistics
Here are the tuning metrics tables (SQL stats are not in “metric” tables per say) (*DBA_HIST_…_HISTORY views are sort of confusing. AFAI remember they were storing alert history, but apparently they...
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