Some time ago – actually a few years ago – I wrote a note about the hint /*+ gather_plan_statistics */ making some informal comments about the implementation and relevant hidden parameters. I’ve recently discovered a couple of notes from Alexander Anokhin describing the feature in far more detail and describing some of the misleading side […]
Tag Archives: performance
Obligatory Melodrama No matter how much time goes by I still remember it. The day my database was crippled beyond reckoning. That moment when I saw my hopes for a bright and shining future with my database spill through my fingers like so many cracker crumbs falling on a clean and well pressed pair of [...]
Carlos Sierra: Since lack of Histograms or freezing CBO Statistics do not guarantee Plan Stability, do not rely on these two myths. If what you are looking for is Plan Stability use then SQL Plan Management available since 11g or SQL Profiles available from 10g. ★ © Eddie Awad’s Blog, 2013. | Permalink | Add [...]★
Dominic Brooks published a note recently about some very nasty SQL – originally thinking that it was displaying a run-time problem due to the extreme number of copies of the lnnvl() function the optimizer had produced. In fact it turned out to be a parse-time problem rather than a run-time problem, but when I first read … … Continue reading →
Anyone who has used Kevin Closson’s “Silly Little Oracle Benchmark” will want to know about his significantly updated SLOB2.