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Diff B/W Truncate & Delete

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Delete
1.DML data can be recovered by rollback before commit
2.Remove any subset of data
3.Delete is slower when table have numerous indexes and triggers
4.DML triggers fire for delete mthod
5.data can be recovered after commit by flashback method
6.high water mark will remain the same
7.data deleted info capture with returning clause
8. you can not delete data if function based index is invalid
9. can not delete data from complex views.
10. Space is not freed

mikerajendran's picture

Oracle Database 12c: New Features - Pluggable Databases

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Oracle Database 12c: New Features – Pluggable Databases by Michael Rajendran

Introduction

The COST column of EXPLAIN PLAN

The COST column cannot be used to compare execution plans. Punkt.

vamsi kasina's picture

R12 - XLA / FAH - Create Accounting errs out with "95357 - There are no values for the system source XXXXX used by SLA"

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In case of unitended usage of system source in conditions may lead to the following error in Create Accounting:
There is a missing system source value. Please inform your system administrator or support representative that: There are no values for the system source XXXXXXXXXXXXXXXXX used by Oracle Subledger Accounting.

What data type should I use: CHAR or VARCHAR2???

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Hi,

We all know that CHAR and VARCHAR2 are two different datatypes used for storing strings in Oracle. When I asked many people about what’s the difference exactly, all were saying VARCHAR2 can be used for variable sized character strings. As I’m not satesfied with the answer, as always, I’ve decided to do my own experiments on these two. Please find the exercise I’ve performed below.

SQL> create table t1 (col1 char(10), col2 varchar2(10));

Table created.

SQL> insert into t1 values(‘Oracle’,'Oracle’);

1 row created.

“ORA-01081: cannot start already-running ORACLE” While creating a new Database

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Hi Geeks,

When I was doing a research on Oracle Database creation, through DBCA, last week, I came across a very interesting scenario which I couldn’t stop sharing with you :)

I have a cluster of machines (don’t confuse it with a RAC cluster but just a group of machines required for my application deployment) with 11.2.0.2 installed and a Database instance running.

I got a requirement to remove everything accumulated in the machine as a result of the Oracle installation and the Database creation: The installation directories, the datafiles, oratab entries etc…

Can you create objects in a READ ONLY tablespace?

Hi Oracle geeks,

Last Friday, I’ve noticed a strange thing happening in my 11.2.0.3 Database: I’m able to create objects in a tablespace which is marked READ ONLY !!!

Don’t believe this?? See the below

SQL> create tablespace ro datafile ‘/xxx/RO.DBF’ size 10M AUTOEXTEND ON;
Tablespace created.

SQL> alter tablespace ro read only;
Tablespace altered.

SQL> select status from dba_tablespaces where tablespace_name=’RO’;
STATUS
———
READ ONLY

SQL> sho user
USER is “CSM“

Key Value Pair Data Model

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I have just joined an in flight project and find the lead data modeler has created a name value pair data model.

The reason given was flexibility of data model considering some records can have as many as 900 attributes. The .Net application team seem to be loving it, as they can code everything with very few tables in mind.

I feel the model is difficult to query, difficult to load and difficult to syndicate and in all likelyhood will suffer from poor performance. Also the data model can't be considered as a rich metadata repository and difficult to understand.

Tools to Administer, Monitor and Tune the Oracle Database.

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I just posted a complete integrated set of tools to manage, monitor and tune the Oracle database.

It is free, no registration or email is required. I will just appreciate any kind of feedback to make it better.

The package comprises the following topics:

Objects
This section allows you to view and maintain virtually all database objects, including partitioned tables and materialized views. It also includes a function to view inter-dependency between objects.

1Z0-052 Oracle DBA Admin 1 OCA Study Guide by Matthew Morris: Review

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Matthew Morris (who makes many constructive and knowledgeable contributions to the forum) has written a series of study guides for the OCA/OCP exams. I asked him if I could have a copy of one to review. The result: it's very good. This is a copy of the review I put up on Amazon.

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