Enriching Trace with Call Stacks Part 2: gdb
How to use gdb for capturing call stacks when trace lines are written Continue Reading
Month: September 2019
WRH$_SYSMETRIC_HISTORY_INDEX UNUSABLE After 18c Upgrade
The index WRH$_SYSMETRIC_HISTORY_INDEX became UNUSABLE a couple of days after the Oracle 18c upgrade Continue Reading
Old-Style (non-cost-based) Join Predicate Push-Down Transformation Part 2 (Recursive WITH)
Wrong cost calculation with recursive WITH subquery and OJPPD Continue Reading
Bad commit Performance due to Slow Control File Writes
Analyzing slow commits with ash_wait_chains.sql, gdb and DTrace Continue Reading
Cost Propagation Errors
Reporting optimizer mistakes where the cost of operations in the execution plan wasn’t propagated to their parents Continue Reading