Databases@Powered by Passion

  • DBMS_METADATA.GET_DDL command

    DBMS_METADATA.GET_DDL Does Not Return Hashed Passwords Anymore

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    by

    Osman DİNÇ
    , ,

    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.

  • Disable Compression Advisor

    Disabling the Oracle Compression Advisor

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    by

    Osman DİNÇ
    ,

    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.

  • SQL Plan Baselines, SQL Patches and SQL Profiles

    SQL Plan Baseline, SQL Patch, SQL Profile: Differences and Use Cases

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    by

    Osman DİNÇ
    , ,

    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.

  • Exadata Management Switch

    Exadata: Configure Management Network Switch with multiple uplinks for redundant connectivity

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    by

    Osman DİNÇ
    , ,

    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

  • Lost private interconnect between Oracle RAC nodes

    Resolving Oracle RAC Node Eviction Issue caused by Cluster Interconnect

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    by

    Osman DİNÇ
    ,

    This post discusses a perplexing issue with node evictions in an Oracle RAC setup, where node crashes occurred due to a loss of connection on a private interconnect despite redundancy. It highlights troubleshooting steps and findings, particularly focusing on the cluster_interconnects parameter. Ultimately, the solution involved resetting this parameter to default values, enabling the use of Highly Available IPs for improved reliability and communication in the cluster.