Category: Oracle
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Oracle Database 19c APEX Upgrade: 19.2 to 24.1.7
This post outlines the process for upgrading Oracle Application Express (APEX) from version 19.2 to 24.1. APEX is a low-code platform for developing web applications with Oracle Database. The upgrade process is independent of the database version but requires Oracle Database version 19c or later. The steps include downloading the new version, creating dedicated tablespaces, executing installation scripts, modifying request-handling procedures, and dropping the old APEX user and tablespace. Finally, the latest cumulative patch, released on December 9, 2024, is applied to ensure a secure, reliable, and efficient APEX environment.
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Oracle Incrementally Updated Backups : Detect and Delete Orphaned (Expired) Datafile Copies
Oracle recommends adopting a merged incremental disk backup strategy to ensure efficient database protection and faster recovery times. This includes keeping an up-to-date image copy as the base while applying incremental backups. Key practices involve setting a REDUNDANCY 1 retention policy, utilizing the Fast Recovery Area, and employing Block Change Tracking for efficiency. DBAs must manage leftover datafiles after tablespace deletion to ensure that the base image copy remains in sync with the database, as detailed throughout the blog post.
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CPU-intensive query to simulate CPU load in Oracle database
This blog post provides a PL/SQL script that utilizes Oracle’s DBMS_SCHEDULER to create and execute CPU-bound jobs. Also validates the CPU usage with AWR Report and docker stats command. Additionally, it addresses constraints of the Oracle Database 23ai Free version, limiting CPU usage to two cores, despite available resources.
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Finding Row Counts for All Tables in Oracle Database
This post explores the debate between using table statistics and executing SELECT COUNT(*) queries for retrieving row counts for all tables in Oracle databases. It highlights the efficiency of relying on table statistics, which require minimal buffer gets (20–29) compared to the substantial overhead of directly counting rows, as observed in the test case with buffer gets reaching up to 492,252. Online statistics(12c) and Real-Time Statistics(19c) features are also highlighted. Overall, it recommends only using table statistics for row count retrieval when querying all tables in the database or schema.
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Table Statistics vs. SELECT COUNT: What to Choose?
Counting rows in database tables is a common concern for DBAs, as it’s highly discussed in forums like ASKTOM and Stack Overflow. Despite its performance drawbacks, developers/dbas often use row counts for data validation during migrations, capacity planning, anomaly detection, and performance tuning. The use of table statistics and computing the exact row count with ‘SELECT COUNT(*) FROM’ is debated. The article emphasizes the need to question the necessity of exact row counts in business requirements perspective.
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Installing Oracle Database 23ai on ARM Macs with Sample Schemas
Released on 12th November 2024, Oracle Database 23ai now offers free container images optimized for ARM-based Apple MacBook computers with M-series chips, enhancing development efficiency. Two image options, Full and Lite, are designed to meet diverse requirements. This post details the process for setting up the Oracle Database using Docker, checking logs, connecting with SQLcl, and importing sample schemas(HR,SH and CO), providing Mac developers with an efficient way to create test environments.
Osman’s DBlog 