Index Skip Scanning In previous releases a composite index could only be used if the first column, the leading edge, of the index was referenced…
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Tag: performance
Postgres Execution Plans
In this blog post, we’ll see What is an SQL Execution Plan? Postgres documentation says: The execution plan shows how the table(s) referenced by the statement will…
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Commit_Delay and Wal_Writer_Delay Parameters Effect in Postgresql Performance
This article aims to provide practical insights into optimizing PostgreSQL database performance by adjusting the commit_delay and wal_writer_delay configuration parameters. The focus is on improving system responsiveness, reducing write…
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Using the Oracle 11GR2 database flash cache
Oracle just released a patch which allows you to use the database flash cache on Oracle Enterprise Linux even if you don’t have exadata storage. …
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What is the usecase of dev shm
/dev/shm is a temporary file storage filesystem (see tmpfs) that uses RAM for the storage. It can function as shared memory that facilitates IPC. It is a…
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How much memory is truly used by my Oracle instance?
There are many posts about the amount of memory that is taken by the Oracle database executables and the database SGA and PGA. The reason…
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How to trace SQL sessions to identify Oracle Database bottlenecks
Want your database to run faster? While common tuning techniques can prove quite helpful in resolving many performance issues, they don’t show the details of all the…
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Understanding Postgres GIN Indexes: The Good and the Bad
Adding, tuning and removing indexes is an essential part of maintaining an application that uses a database. Oftentimes, our applications rely on sophisticated database features…
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Performance Tuning Queries in PostgreSQL
Database performance tuning: developers usually either love it or loathe it. I happen to be one that enjoys it and want to share some of…
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Correlated subquery
In a SQL database query, a correlated subquery (also known as a synchronized subquery) is a subquery (a query nested inside another query) that uses values from the outer query. Because…
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