How to fix cardinality misestimate?
In this post, I am going to explain how to correct the cardinality estimate in 5 different methods. Cardinality estimate is one of the first place to check […]
More DetailsCUME_DIST function
In this post, I would like to explain a function that is not well known. CUME_DIST analytic function is used for calculating the cumulative distribution of a data […]
More DetailsFOR UPDATE vs FOR UPDATE SKIP LOCKED
In this post, I am going to explain how FOR UPDATE and FOR UPDATE SKIP LOCKED clauses work. I would like to demonstrate it with a basic example. […]
More DetailsNVL vs COALESCE
As it is known, NVL and COALESCE functions are used in order to eliminate NULL values. However, NVL function is much more popular in comparison with the COALESCE. […]
More DetailsHow to use MULTISET UNION DISTINCT on collections
Let’s start with a basic example. Suppose, you have two PL/SQL collections with the same data type that you want to merge and remove the repetitive data. You […]
More DetailsHow to use PL/SQL functions within SQL
As it is known, invoking PL/SQL code from SQL cause context switching. SQL is a non-procedural language and it is very different from PL/SQL language. In addition, PL/SQL […]
More DetailsThe power of MATCH_RECOGNIZE
MATCH_RECOGNIZE is one of the most powerful feature of SQL. There are several use cases, such as finding series of consecutive rows, pattern matching, etc. Once you understand […]
More DetailsLISTAGG Enhancements
If you consider to aggregate data from multiple rows into a single column, LISTAGG might be the first function that comes to your mind. It has been enhanced […]
More DetailsWITH clause and Depth First Search
In this article, I am going to explain how you can implement the depth first search with using the WITH clause or also known as subquery factoring clause. […]
More DetailsHow to reorder columns of table
If you want to change the order of the columns of any table without recreating it, then the following trick will work for you. Suppose you want to […]
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