g*******g
发帖数: 108 | 1 I posted the following in "c*****[email protected]".
Hello guys:
Let's work together to compile a list of popular misconceptions about
Oracle DB management/practics? It will help new Chinese DBAs to get to the
Senior level
1) Buffer Cache Hit Ratio is a good performance tuning factor. This is
not true,
2) Rebuilt index regularly helps performance. This is not true. indexes
are rarely needed to be rebuilt.
See richard foote's note on index internal.http://richardfoote.wordpress.com/category/index-rebuild/
3) Bitmap index always works better on low cardinality column index. (
male/female ).
bitmap is used to do flexible columns joins, not for low
cardinality join.
4) table partition alone helps performance.
Tom Kyte discussed this in his books, and asktom.oracle.com.
table partition alone rarely improve query performance. Code changes are
needed. Parallel.
Guys please feel free to add your favorite Oracle myth/misconception etc. |
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