Monthly Archives: April 2015

Direct Path Read and “enq: KO – fast object checkpoint”

Introduction When using direct path read, oracle reads the blocks from the disk. The buffer cache is not being used. Then, when oracle begins to read a segment using direct path read, it flush its dirty blocks to disk (A dirty block … Continue reading

Posted in Performance | 8 Comments

ASM Bytes Read and Smart Scan

Introduction I like to query the v$asm_disk_iostat cumulative view (at the ASM instance level) as this is a centralized location where you can find metrics for all the databases the ASM instance is servicing. One of its metric is: BYTES_READ: Total number … Continue reading

Posted in Exadata | 2 Comments