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The answer is right there, in the data. (I assume that the time part is 00:00:00 in all of them): The order by has ties. There is not one "first row" but 3 of them. So, when the 2nd query restricts the result to one row, one of the 3 is - arbitrarily - chosen. It may not be the same row chosen the next time you run the same query!


Introduction to the Oracle Database Instance A database instance is a set of memory structures that manage database files. A database is a set of physical files on disk created by the CREATE DATABASE statement. The instance manages its associated data and serves the users of the database. Every running Oracle database is associated with at ...


db_block_size is the default block size of the database, but it does not necessarily mean all your tablespaces have the same block size, you can have tablespaces with different block sizes. You need to define seperate cache areas for tablespaces with non-default block size. For example, if your db_block_size is 8192, and you want to create a tablespace with ...


Yes, databases can be created without using DBCA from command line. 1) you need to export required environment variables 2) Create a parameter file (init$sid.ora) under $ORACLE_HOME/dbs substitute $sid with your instance name. 3) Create a SQL script for database creation 4) Connect to sqlplus, put the instance in no mount state and run the script to ...

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