Everything our consultants learn while running databases for customers: Oracle, PostgreSQL, SQL Server, MySQL, MariaDB, MongoDB and Delphix. Expect hands-on posts about installation, day-to-day administration, backup and recovery, performance tuning, replication and upgrades.
By William Sescu After installing OUD some time ago, I was doing some tests to see how it performs, and as long as I do ldap searching on the command line it looks very good. I am running Unified Directory 11.1.2.3.170117 (latest PSU), just for the protocol and I use the OUD only for TNS resolving and nothing else. However,…
By William Sescu The default configuration which is shipped with OUD is not meant to be ready for enterprise usage. The default settings of OUD are targeted at evaluators and developers who run equipment with limited resources, and so it is quite likely that you run into performance issues if you don’t change anything, before going into production. The OUD…
This is a question that comes up quite often: How can I use optimizer hints in PostgreSQL as I can do it in Oracle? Well, you cant, and the reasons are this: Poor application code maintainability: hints in queries require massive refactoring. Interference with upgrades: today’s helpful hints become anti-performance after an upgrade. Encouraging bad DBA habits slap a hint…
By Franck Pachot . This post explains the following error encountered when creating a 12.2 database with DBCA: [DBT-11211] The Automatic Memory Management option is not allowed when the total physical memory is greater than 4GB. or when creating the database directly with the installer: [INS-35178]The Automatic Memory Management option is not allowed when the total physical memory is greater…
By Franck Pachot . 11gR2 started to have the optimizer react at execution time when a misestimate is encountered. Then the next executions are re-optimized with more accurate estimation, derived from the execution statistics. This was called cardinality feedback. Unfortunately, in rare cases we had a fast execution plan with bad estimations, and better estimations lead to worse execution plan.…
Following the last post about which tools you can use to create your PostgreSQL instance in this post we’ll look at how you can do the “create database” part that you would do in Oracle when not using the database configuration assistant. Of course can can create a database in PostgreSQL but it is not the same as it is…
Short answer: No. Long answer: No. Every other possible answer: No. There is no such tool in PostgreSQL. In Oracle you can use the database configuration assistant to create your Oracle database. But this is not a must, you can do the same using scripts. Either you use dbca to generate scripts based on the questions you answered in the…
In this blog post let’s talk a little bit about SQL Server optimal installation on the Linux file system. This is probably one of the first considerations we will have as a database administrator. Actually basic installation of SQL Server can be resumed to use yum command and let the SQL Server installer place all related files on the file…
Today I had a very strange issue when setting up a brand new GoldenGate 12.2 installation. Installation went fine, patch went fine (PSU 170221) and then I started to configure GoldenGate. One of the first commands we usually do is: GGSCI (xxxxx) 2> create wallet I really never had any issues with this, but today I got: GGSCI (psrdbap03n1) 2>…
Following the last post about time zones this post is about the display and default format of date and time values. What people usually do to get a consistent display of date and time values in Oracle is to set NLS_DATE_FORMAT: SQL> show parameter nls_date_format; NAME TYPE VALUE ———————————— ———– —————————— nls_date_format string YYYY-MON-DD HH24:MI:SS SQL> alter session set nls_date_format=’DD.MM.YYYY…
By William Sescu Backing up an OUD consists of several components The OUD software itself The OUD back end data The OUD configuration The OUD logical export as a ldif file However, in this post I would like to take a closer look at the back end data. Unlike the old OID, the OUD directory server uses the Berkeley DB…
This post is inspired by a question we received from a customer: In Oracle there is the sessiontimezone which returns the time zone of the session. Asking for the time zone of the session in Oracle returns you the offset to the UTC time: SQL> select sessiontimezone from dual; SESSIONTIMEZONE ————————————————————————— +02:00 This is fine as I am based in…
