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  • Tips’n’tricks: understanding “too many authentication failures” in SSH

    Virtualbox VMs powered by Vagrant require authentication via SSH keys so you don’t have to provide a password each time vagrant up is doing its magic. Provisioning tools you run as part of the vagrant up command also rely on the SSH key based authentication to work properly. This is documented in the official Vagrant…

  • Ansible Tips’n’tricks: rebooting Vagrant boxes after a kernel upgrade

    Occasionally I have to reboot my Vagrant boxes after kernel updates have been installed as part of an Ansible playbook during the “vagrant up” command execution. I create my own Vagrant base boxes because that’s more convenient for me than pulling them from Vagrant’s cloud. However they, too, need TLC and updates. So long story…

  • orachk can now warn about unwanted cleanup of files in /var/tmp/.oracle

    Some time ago @martinberx mentioned on twitter that one of his Linux systems suffered from Clusterware issues for which there wasn’t a readily available explanation. It turned out that the problem he faced were unwanted (from an Oracle perspective at least) automatic cleanup operations in /var/tmp/.oracle. You can read more at the original blog post.…

  • Ansible tips’n’tricks: executing a loop conditionally

    When writing playbooks, I occasionally add optional tasks. These tasks are only executed if a corresponding configuration variable is defined. I usually define configuration variables either in group_vars/* or alternatively in the role’s roleName/default/ directory. The “when” keyword can be used to test for the presence of a variable and execute a task if the…

  • Dead Connection Detection (DCD) and the Oracle database

    Dead Connection Detection is a useful feature of the Oracle database: it allows for the cleanup of “dead” sessions so they don’t linger around consuming memory and other system resources. The idea is simple: if the database detects that a client process is no longer connected to its server process, it cleans up. This can…

  • Little things worth knowing: keeping enq: TM enqueue at bay during direct path inserts

    Direct path inserts are commonly found in processing where data are shifted from one source to another. There are many permutations of the theme, this post details the way SQL Loader (sqlldr) behaves. I have previously written about sqlldr and concurrent direct path inserts. The behaviour for releases <= 12.1 is described in the first…

  • ORA-14300 partitioning key maps to a partition outside maximum permitted number of partitions and NULLs

    While researching interval partitioning in Oracle 19c I came across a phenomenon I had already solved a long time ago but then forgot about. This time I decided to write about it so I don’t have to spend 5 minutes rediscovering the wheel. As always, if you are following along, make sure you are appropriately…

  • sqlldr, direct path loads and concurrency in 12.2 and later

    In my previous post I showed you that Oracle’s SQL loader (sqlldr) utility has a built-in timeout of 30 seconds waiting for locked resources before returning SQL*Loader-951/ORA-604/ORA-54 errors and failing to load data. This can cause quite some trouble! Before showing you the enhancement in 12.2 and later, here is the gist of the previous…

  • sqlldr, direct path loads and concurrency in 12.1 and earlier

    I have recently come across an interesting issue related to concurrent data loading into the Oracle database using sqlldr’s direct path mode. Although I investigated the situation on 12.1.0.2, I found that the same holds true in 19.4 as well when using the defaults. I reconstructed the case, although it is simplified a little to…

  • Ansible tips’n’tricks: checking if a systemd service is running

    I have been working on an Ansible playbook to update Oracle’s Tracefile Analyser (TFA). If you have been following this blog over the past few months you might remember that I’m a great fan of the tool! Using Ansible makes my life a lot easier: when deploying a new system I can ensure that I’m…