SQL Server vs Oracle Query Statistics to Improve Performance
In this article, learn how to query cached query statistics and execution plans for Oracle or SQL Server to identify code that can be optimized to improve performance.
2023-07-21
Oracle
The SELECT Statement in Oracle
The SELECT statement is used to retrieve information from a database. Following the execution of a SELECT statement, a tabular result is held in a result table (called a result set). It allows you to select the table columns depending on a set of criteria. In this article, I will introduce the basic SELECT statement fetching data from just one table.
2023-06-21
Oracle optimizer removing or coalescing subqueries
The Oracle optimizer often changes the query to get better performance. In this article, Jonathan Lewis explains two more optimizations involving subqueries.
2022-05-25
Why your PL/SQL needs to be testable – and how to do it: Part 1
Part 1: What is testable code, why is it important, and first glimpses on practices that can help
2022-04-27
Oracle subquery caching and subquery pushing
In this article, Jonathan Lewis discusses why you might want to stop the optimizer from unnesting some subqueries and how to control where the optimizer positions each subquery.
2022-04-11
The effects of NULL with NOT IN on Oracle transformations
IN and NOT IN subqueries are frequently used in Oracle. Jonathan Lewis explains how the optimizer handles NULL with IN and NOT IN.
2022-03-18
Oracle ASM: Migrating from UDEV devices to the ASM Filter Driver
This article looks at the way in which you can convert unmanaged devices to the ASM filter drive in an Oracle system.
2022-03-04
2,966 reads
Running SQL Server on Oracle and Google Cloud
In this article, we will analyze the various out-of-the-box deployment options Oracle Cloud Infrastructure and Google Cloud Platform offers to host a Microsoft SQL Server database. This information can prove to be handy while deciding on the best cloud provider to host a given application or database.
2022-02-18
6,605 reads
Transformations by the Oracle Optimizer
To troubleshoot poorly performing SQL in Oracle, you must understand which transformations the optimizer has made. Jonathan Lewis demonstrates several possible optimizations for one query.
2022-02-09
Oracle sequences – 12c features including “identity”
Oracle added several enhancements to the sequence object in version 12c, including an “identity” column feature. Jonathan Lewis explains how to work with these new features.
2021-09-10
Blogs
Dynamically Unpivot columns in SQL
By DataOnWheels
Picture this, your data ingestion team has created a table that has the sales...
Friday Basics: RPO and RTO
By Brian Kelley
I did a post last month titled RTO and RPO are myths unless you've...
A New Word: ioia
By Steve Jones
ioia – n.the wish that you could see statistics overlaid on every person you...
Forums
SQL Server Encrypt data into a file, send it and then decrypt
First off, my apologies for what could potentially be a bad title! I am...
Table partitioning best practice
I've inherited a couple of rather large databases from my ex-colleague when I join...
Identifying Customer Buying Pattern in Power BI - Part 2
Comments posted to this topic are about the item Identifying Customer Buying Pattern in...
Question of the Day
Finding Marks
I have marked a few transactions in my code. How can I find out which marks were stored in a transaction log?
See possible answers