PostgreSQL EzzEddin Abdullah in PostgreSQL PostgreSQL Performance Troubleshooting: EXPLAIN, Index Design, Unique and Partial Indexes Troubleshooting and fixing PostgreSQL performance issues - using EXPLAIN and EXPLAIN ANALYZE to diagnose slow queries, designing unique indexes for... 25 May 2022 14 min read
Database Administration Robert Sheldon in Database Administration Retrieving SQL Server Query Execution Plans Execution plans explain all you need to know about query performance, and how to fine-tune. Sure, you can see them... 18 October 2016 26 min read
Dennes Torres SQL Server Batch Process Optimization: Auto-Growth, Locks, Log Flushes, and Index Fragmentation Step-by-step performance tuning of a SQL Server batch process - identifying and fixing auto-growth events, lock contention, WRITELOG waits, index... 08 May 2015 33 min read
Jonathan Lewis Execution Plans Part 14: SQL Monitoring This is the last part of my series on Execution plans, and features an option which is only available if... 26 March 2015 14 min read
Jonathan Lewis Execution Plans Part 13: SQL Trace In parts 11 and 12 of this series I described the “rowsource execution statistics” that we can collect as Oracle... 11 March 2015 12 min read
Jonathan Lewis Execution Plans Part 12: Cardinality Feedback In the previous instalment of this series I introduced three ways of accessing the run-time statistics for a query and... 13 January 2015 13 min read
Grant Fritchey SQL Server Execution Plans for Developers: Query Tuning Guide by Grant Fritchey Grant Fritchey explains why SQL Server developers need to read execution plans: identify N+1 problems from ORMs, diagnose poorly designed... 12 January 2015 31 min read
Dennes Torres SQL Server Query Plans: Finding Scan and Lookup Problems with DMVs and XQuery Use SQL Server DMVs (sys.dm_db_index_usage_stats) and XQuery against cached query plans to find queries causing scan and lookup problems. Converts... 31 December 2014 15 min read
Jonathan Lewis Execution Plans Part 11: Actuals So far in this series we’ve talked about interpreting the shape of an execution plan and understanding the meaning of... 17 December 2014 13 min read
Jonathan Lewis Execution Plans Part 10: Guesswork In part 9 we saw an example of a simple nested loop join where the basic method for interpreting the... 09 September 2014 9 min read
Jonathan Lewis Execution Plans Part 9: Multiplication In part 8 we looked at a very simple execution plan involving a hash join; but that example was too... 29 August 2014 7 min read
Jonathan Lewis Execution Plans Part 8: Cost, time, etc. It’s time to move away from the shape of an execution plan and turn our attention to some of the... 19 August 2014 11 min read
Jonathan Lewis Execution Plans Part 7: Query Blocks and Inline Views When we examine an execution plan, we’re usually trying to work out the mechanical steps that Oracle took to produce... 09 July 2014 10 min read
Jonathan Lewis Execution Plans Part 6: Pushed Subqueries In part 5 of this series we examined a couple of examples where you had to handle the “first child... 16 June 2014 10 min read
Jonathan Lewis Execution Plans part 5: First Child Variations I’ve offered up “first child first, recursive descent” as a basic strategy for interpreting execution plans – but it’s not... 28 May 2014 14 min read
Jonathan Lewis Execution Plans Part 4: Precision and Timing In part 3 of this series we used a simple hash join to introduce the a simple guideline for reading... 14 May 2014 12 min read
Houri SPM Plan: non reproducibility circumstances and CBO interaction 1. Introduction When a critical report which used to complete very quickly starts performing poorly, there is a big chance... 01 May 2014 17 min read
Jonathan Lewis Execution Plans Part 3: “The Rule” In the first two articles in this series we listed a couple of methods for generating or retrieving execution plans... 25 April 2014 13 min read
Jonathan Lewis Execution Plans Part 2: Things to see In part 1 of this series we saw two basic ways of creating, or acquiring, execution plans. The first method... 26 March 2014 12 min read
Jonathan Lewis Execution Plans: Part 1 Finding plans If you have to tackle performance problems in an Oracle database one of the most important skills you need to... 12 March 2014 14 min read
