WINDOW SORT PUSHED RANK Performance Regression in Oracle 21c
New optimization causing severe performance degradation. It can be switched off with the fix control. Continue Reading
Month: June 2022
Workaround for Non-Functioning uretprobes with Oracle Database Software
Oracle database software breaks uprobes and uretprobes. The workaround for uprobes is well known – adding an offset to the function entry. This article explains how to emulate uretprobes with uprobes as a workaround. Continue Reading
killsnoop Limitation
The current implementation of the eBPF bcc tool killsnoop doesn’t capture signals sent by the tgkill() system call. Continue Reading
oradebug request completion
Exploring the internals of the undocumented Oracle wait event “oradebug request completion” with eBPF. An example of an off-CPU analysis. Continue Reading
Perilous New Undocumented Tracing Feature in Oracle 21c
Database writer performance impaired by sudden debug trace. Continue Reading