Execution plan

Postgres vs. Oracle access paths I – Seq Scan

By Franck Pachot . Here is the first test I've done for my Postgres vs. Oracle access paths series and the first query did a sequential scan. It illustrates the first constant you find in the(…)

Postgres vs. Oracle access paths – intro

By Franck Pachot . This is the start of a series on PostgreSQL execution plans, access path, join methods, hints and execution statistics. The approach will compare Postgres and Oracle. It is not a comparison to see which one is(…)

Postgres vs. Oracle access paths VII – Bitmap Index Scan

By Franck Pachot . In the previous post we have seen the Index Scan, where a where clause condition uses the index structure to find rows and then fetches remaining columns from the table. The case(…)

SQL Server 2016 : nonclustered columnstore index and aggregate pushdown

Did you miss aggregate pushdown capability shipped with columnstore index? Well, I remember the first time I heard about it is was when I read the very interesting blog post of Niko Neugebauer here with a(…)

Dynamic filters and “kitchen sink” queries dilemma

Dealing with dynamic filters is a common scenario with management software or ERP. Indeed, users should like to have the flexibility to filter and sort their business data as they want in order to be efficient. Target and operate quickly(…)

SQL Server 2016 query store

One of the most new interesting features that will be introduced by SQL Server 2016 is certainly the query store that will complete the performance tuning toolbox of database administrators. Basically, the query store will track queries, their query plans(…)

A funny story with recompile hint at statement level

Last night, I had an interesting discussion with one of my MVP French friend that faces a weird situation where a query that uses a statement level RECOMPILE hint produces an execution plan that disappointed him. He told me we(…)

SQL Server 2014: sys.dm_exec_query_profiles, a new promising feature

Among the hidden features provided by SQL Server 2014 there is a very interesting dynamic management view named sys.dm_exec_query_profiles. This feature will help the database administrators and experienced developers to troubleshoot long running queries in real-time. I’m pretty sure(…)

Oracle SQL Monitoring reports in flash, html, text

By Franck Pachot . I have recently posted on the way I like to extract execution plans. When we have Tuning pack, I suggest to get them with SQL Real-Time Monitoring as an active report. However, Martin Preiss said(…)

Best practice for the sending of an Oracle execution plan

By Franck Pachot . You have a query that takes too long and you want help to analyze the execution plan? Then you need to get it with relevant information, and correctly formatted. Autotrace is not a good option(…)