Category: Oracle
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Oracle Hash Partitioning: Benefits, Limitations and Best Practices
Hash partitioning enhances database management and performance by evenly distributing data across partitions, crucial for handling high concurrency. However, choosing an appropriate partition key is vital to avoid skewed data distribution. Proper use of partition keys allows for efficient query performance and reduces contention in both single-instance and RAC environments.
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DBMS_METADATA.GET_DDL No Longer Shows Password Hashesr
Recent Oracle Data Pump patches (19.17 and later, involving bug fix 33517865) have modified the behavior of DBMS_METADATA.GET_DDL, removing hashed passwords from its output as a security enhancement. Previously, users with the EXP_FULL_DATABASE role could easily access this data. Now, even with that privilege, hashed passwords are inaccessible unless explicit access to SYS.USER$ is granted. Oracle has introduced a fix (bug fix 35018026) that allows access to hashed passwords under strict conditions. Alternatively, a definer-rights PL/SQL function can be used to provide controlled access to this information.
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Ansible Playbooks for Oracle Grid and Database Release Update (19.26 with MRP & One-Off Fixes)
In this post, I’m sharing the latest Ansible playbooks for patching Oracle Database and Grid Infrastructure, specifically for the Oracle 19.26 Release Update, including MRPs and recommended one-off fixes. Ansible simplifies the patching process, providing repeatability and ease.
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Disabling the Oracle Compression Advisor
A recent incident regarding tablespace usage occurred during the daily maintenance window, leading to an ORA-1652 error. The issue stemmed from the Compression Advisor creating large CMP3$ tables, causing space pressure in the USERS_XXX tablespace. The problem resolved itself once the advisor completed, freeing up space. With Oracle 12.2+, users can now disable the Compression Advisor specifically without turning off the Segment Space Advisor, offering better management options and addressing similar future issues effectively.
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SQL Plan Baseline, SQL Patch, SQL Profile: Differences and Precedence
This content highlights the importance of stability in database performance, especially regarding Oracle’s SQL execution plans, which can fluctuate based on various factors. It focuses on three primary methods for influencing execution plans: SQL Plan Baselines, SQL Patches and SQL Profiles and providing a detailed explanation of how each method functions. It includes a test scenario where all three options are used, demonstrating their behavior. Additionally, it presents a conflicting scenario to help determine the precedence of these methods.
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Oracle Exadata: Configure Management Cisco Network Switch
This post outlines the steps to configure Cisco Management Network Switches with multiple uplinks for redundancy in Oracle Exadata environments. It emphasizes the importance of the Administration Network, which connects all Exadata components for management purposes. Detailed steps are provided for configuring a Cisco 9348 Ethernet Switch, including LACP setup for uplink ports and validating spanning tree settings to ensure stable and reliable connectivity
