Enriching Trace with Call Stacks Part 2: gdb
How to use gdb for capturing call stacks when trace lines are written Continue Reading
Author: Nenad Noveljic
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
Old-style (non-cost-based) Join Predicate Push-Down Transformation
Suboptimal execution plans after falling back to OJPPD with hierarchical subqueries Continue Reading
Tracking Arguments with gdb
Tracking function arguments with gdb, with an example of tracing memory allocations in Oracle database Continue Reading
IO Sort Cost Calculation (2)
Interpreting formulae; comparison to full table scan calculation Continue Reading
IO Sort Cost Calculation
IO Sort Cost Calculation: formulae and internals Continue Reading
Extracting Join Order from Optimizer Trace
Programmatically extracting join order information from optimizer trace Continue Reading