Get cache buffer LRU chain latch to find a free buffer in buffer cache,
– Avoid reading from disk
. Cache tables/indexes
. Use KEEP / RECYCLE pool
the SQL statement on a faster part of the disk.
to return data faster.
4. Bad application design
1. Examine the SQL statement to see if
. it is doing a full-table scan when it should be using an index,
. it is using a wrong index or
. it can be rewritten to reduce the amount of data it retrieves
. it is appropriate for the SQL statements to access data through index lookups or would full table scan be more efficient?
. the statements use the right drivin table i.e. join order is proper?
5. Range scans on data spread in many different blocks
DB FILE PARALLEL READ
Clustering Factor Demystified Part – I
ClusteringFactor Demystified Part – II
Consistent Reads In Oracle: Part-I
Direct Read Enhancements in 11g
Simulate Buffer Busy Wait and Identify Hot Object