Base on execution plan take the following steps
- Improved offloading/smart scan by eliminating unnecessary indexing (simply change index to be invisible and then check execution plan,…, repeat step)
- check and find the reason for “quarantines for sql”
- Eliminate any reason for “reading extra block” during full table scan, like “read consistency, row chaining & migration, …
- Set properly table storage parameters:
- The small table threshold (_small_table_threshold parameter) is determining factor for full scans. (setting/calculation depending on version and it is relative size of segment to buffer cache). Note: partition is segment
- set properly parameters for parallel processing & PX Adaptive offloading
- force direct path read & Bloom Filter;
- set properly parameters for parallel processing & PX Adaptive offloading;
That’s it
Andjelko