Enriching Trace with Call Stacks
A DTrace script for capturing the call stack when a line gets written into the trace file. It’s useful, for example, for finding out the functions participating in a particular query transformation. Continue Reading
Oracle
Suboptimal Execution Plan with Join Predicate Push-Down Transformation
JPPD is performed where it shouldn’t. Use the CBO trace parser for detecting the problem. Continue Reading
Dissecting Cost Based OR-Expansion
Analyzing the CBO trace for getting insight into the cost based OR-expansion Continue Reading
SQLNet Tracing’s Blind Spot
SQLNet client trace is missing. Continue Reading
Fast Retrieval of DYNAMIC_SAMPLING_RESULT Information
Correlating an active dynamic sampling trace with the data dictionary Continue Reading
Converting HASH_VALUE to SQL_ID
Converting HASH_VALUE to SQL_ID with SQL Continue Reading
SQL for Converting Decimal Integers to Any Base
A single SQL converts unsigned decimal integers to any other base. Continue Reading
first_rows Optimization in Uncorrelated Subqueries
Suboptimal execution plans can be generated for uncorrelated subqueries involved in set operations. Continue Reading
Dead Transaction Rollback
A crashed process can leave a dead transaction behind. Generally, SMON is the one who’ll be rolling it back. Under certain circumstances, though, a server process might lend a helping hand. That’s exactly the scenario we’ll be focusing on. Continue Reading
Negative Unaccounted-for (2) – Pitfalls
Find out which information in SQL Monitor report and ASH becomes unreliable in the case of a negative unaccounted-for. Continue Reading