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9

The query is syntactically correct even if table_b has not a name column. When the query is parsed, it is first cheched whether table_b has name column. Since it doesn't, then table_a is checked. It would throw an error only if neither of the tables had a name column. Finally the query is executed as: select a.* from table_a a where a.name in (select ...


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There is no name field in table_b so Oracle takes the one from table_a. I tried the EXPLAIN PLAN but this gave me only that there is a TABLE ACCESS FULL. I presume that this will generate some kind of Cartesian Product between both tables that result in a list of all the names in table_a is returned by the sub-query.


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I have seen this only once so far, but there is an issue described in the My Oracle Suppport note: FIPS use causes ORA-01017: Invalid Username/password with Managed ODP.NET (Doc ID 1937500.1) I will not post the full content of this as it is not public, but here is the essence: This bug has been fixed in 12.1.0.2 Managed Provider. Please note that the ...


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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 ...


2

Because Oracle performs a correlated subquery when a nested subquery references a column from a table referred to a parent statement one level above the subquery. http://docs.oracle.com/cd/E11882_01/server.112/e41084/queries007.htm#SQLRF52357 It means in order to determine whether subquery is correlated Oracle must try to resolve names in ...


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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 ...


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Checking Allow inprocess for the OraOLEDB.Oracle provider seems to have resolved the problem.


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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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