|
You are here |
afatkulin.blogspot.com | ||
| | | | |
oracletoday.blogspot.com
|
|
| | | | | I have been having some performance problems when using autotrace in some production systems. I finally had time to check out why. I enabled... | |
| | | | |
dincosman.com
|
|
| | | | | The performance issue with an SQL query was resolved by using the /*+ PARALLEL(2) */ hint, reducing execution time from 180-200 seconds to milliseconds. The decision to perform a direct read from disk to memory instead of reading blocks from disk was made by the database engine and is controlled by the hidden "_serial_direct_read" parameter.... | |
| | | | |
blog.tanelpoder.com
|
|
| | | | | Hello all fellow Oracle geeks and technology enthusiasts! Long time no see ;-) In the hacking session about Oracle full table scans and direct path reads I explained how the direct path read decision is not done by the optimizer, but instead during every execution, separately for every single segment (partition) scanned in the query. I also explained how the _small_table_thresholdparameter and theX$KCBOQH.NUM_BUF(which keeps track of how many buffers of any segment are currently cached) are used for determining whether to scan using direct path reads or not. - Linux, Oracle, SQL performance tuning and troubleshooting training & writing. | |
| | | | |
afatkulin.blogspot.com
|
|
| | | Most people are aware of the implication hot backup puts on your redo stream. They'll tell you that on first modification Oracle will dump t... | ||