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For years, SQL Plan Management was a powerful but somewhat manual tool in the DBA’s belt — capture baselines, evolve them, accept or reject new plans… rinse and repeat. It worked, but it required attention.With 23ai, Oracle takes a bold step toward self-driving databases: Automatic SQL Plan Management. The database now watches for regressions, evaluates…
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While preparing the series of posts about Clustering Factor (aka CLUF in 10053 traces) I came across an interesting caveat which I decided to explore.I will make an attempt to explain its matter, although I encourage you to reach out to the part3 of the mentioned series and navigate to “Quantifying physical reads for low CLUF” and…
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This post is the continuation of the previous part. Clustering Factor – tests with 10046 Let’s go through the cases represented by SELECT statements and examine the true effort measured with the number of physical reads which are hidden behind a query retrieving its data from the table, yet by the means of either one:…
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You surely came across these two columns while going through DBA_% or Oracle documentation. AVG_LEAF_BLOCKS_PER_KEYAVG_DATA_BLOCKS_PER_KEY They are to be spotted “here and there”. I bet though you may tend to skip them as not important or.. not really well understood, so not important.I will make an attempt to demystify them and show how valuable they…
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Latest posts
- Auto SQL Plan Management (look under the hood) – part 1
- Auto SQL Plan Management (look under the hood) – part 3
- Auto SQL Plan Management (look under the hood) – part 2
- Converting of CPU Costing in the Cost Based Optimizer 10053 Trace File
- Why this extra physical read while performing index scan?
- Clustering Factor (CLUF) – the anatomy and its impact on performance – part4
- Clustering Factor (CLUF) – the anatomy and its impact on performance – part3
- Clustering Factor (CLUF) – the anatomy and its impact on performance – part2
- Clustering Factor (CLUF) – the anatomy and its impact on performance – part1
- Resp in the CBO 10053 Trace File