Negative Unaccounted-for
Analyzing negative unaccounted-for in an Oracle SQL extended trace file profile with DTrace. Continue Reading
Oracle
Database Call CPU Instrumentation
Exploring Oracle database instrumentation internals with DTrace Continue Reading
Tracking Wait Events with DTrace
Measuring Oracle database wait event durations with DTrace Continue Reading
Data Redaction and Virtual Columns
Data Redaction limitation in Oracle 12.2 Continue Reading
Join Cardinality Misestimate (“Adjustment-to-Zero Issue”) in Oracle 12.2 – Part 2
Enhanced example of join cardinality misestimate caused by adjustment-to-zero issue Continue Reading
Cartesian Join with Hierarchical Query
How to avoid wrong cardinalities in cartesian joins Continue Reading
JOIN CARDINALITY MISESTIMATE in Oracle 12.2
Wrong join cardinality estimate due to adaptive dynamic sampling Continue Reading
Cardinality Estimation for “MINUS” Operator
Mind inaccurate cardinality estimations when using MINUS operator in subqueries. Continue Reading
Corruption after “alter table move” in Oracle 12.2
“Alter table move” might cause a corruption in an Oracle 12.2 databases if user defined types are used. Continue Reading
PL/SQL Exception Handling Performance Degradation in Oracle 12.2
Potentially a huge performance issue with PL/SQL exception handling in 12.2 Continue Reading