In a previous article we have analyzed the architecture of Oracle Database (SGA/PGA). This time we will look at the memory architecture of PostgreSQL and the key parameters for optimal performance. The memory model of PostgreSQL differs significantly from that of… read more
What are WALs in PostgreSQL and how do we configure them?
In this article we will look at the mechanism that connects memory to disk and ensures that we will not lose data if the database goes down (e.g. due to power failure): Write-Ahead Logs (WAL) and Checkpoints. When we execute… read more
What is MVCC and Vacuum in PostgreSQL database and how do we avoid Bloat?
In this article we will see how PostgreSQL manages concurrent access through MVCC, what Bloat is, what Data Churn is, what Vacuum is, and how to properly configure it with Autovacuum. What is… read more
How to free up reserved space from datafiles / tempfiles of an Oracle database
In this article we will see a script with which we can easily free up space from datafiles and tempfiles where it is not used in Oracle databases. More specifically, we will reduce the size of the datafiles so that… read more
How do we collect the actual execution plan from queries using Extended Event and how do we read its data
In an earlier article we saw how we activate the Query Store to monitor the performance of the queries and the plan they ran. But as we said, the Query Store has quite a performance impact, so we may want some lightweight profiling. In this... read more
How we collect deadlocked queries via Extended Event and how we read its data
In an earlier article we saw how we create an Extended Event to see queries with a long duration. In this article we will build Extended Event that records deadlocks. All we need to do is create it with a T-SQL command. After… read more
How to transfer bulk datafiles online to Oracle database
In this article we will see a script with which we can transfer mass datafiles online that we may have created in the wrong location or we want to change their storage in an Oracle database. THE… read more
How to improve a previously run query on an Oracle database (SQL Tuning Advisor with AWR Snapshots)
In a previous article we analyzed how to improve a query in Oracle using the SQL Tuning Advisor. But in order to run the SQL Tuning Advisor, the query must still be in the Shared Pool, i.e. in memory... read more
How do we limit the resources that a user can consume in SQL Server
Many times a user in the database can consume all the resources that the SQL Server instance has and no other work can be done by another user. In this article we will see how we can… read more
