Oracle database administration
Find news, tips, scripts and advice covering all the daily tasks of Oracle database administration, including Oracle backup and recovery, installation, upgrades, patching, database design, security, performance and tuning, error messages, availability and RAC, Oracle on Linux, grid computing, data warehousing, and more.
Top Stories
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Video
17 Jul 2024
How to install MySQL on Windows
Need a well-maintained, open-source, standards-based database to test your Java apps and Spring Boot microservices? Here's how to download and install the MySQL Community Edition. Continue Reading
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News
10 Jun 2022
Oracle sets lofty national EHR goal with Cerner acquisition
With its Cerner acquisition, Oracle sets its sights on creating a national, anonymized patient database -- a road filled with technical and legislative hurdles. Continue Reading
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Definition
12 Sep 2024
What is a data fabric?
A data fabric is an architecture and software offering a unified collection of data assets, databases and database architectures within an enterprise. Continue Reading
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Definition
27 Aug 2024
What is Structured Query Language (SQL)?
Structured Query Language (SQL) is a standardized programming language that is used to manage relational databases and perform various operations on the data in them. Continue Reading
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Definition
29 Jul 2024
What is denormalization and how does it work?
Denormalization is the process of adding precomputed redundant data to an otherwise normalized relational database to improve read performance. Continue Reading
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Video
17 Jul 2024
How to install MySQL on Windows
Need a well-maintained, open-source, standards-based database to test your Java apps and Spring Boot microservices? Here's how to download and install the MySQL Community Edition. Continue Reading
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Definition
25 Jun 2024
database management system (DBMS)
A database management system (DBMS) is a software system for creating and managing databases. Continue Reading
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Definition
21 Jun 2024
relational database
A relational database is a type of database that organizes data points with defined relationships for easy access. Continue Reading
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Definition
06 Jun 2024
RDBMS (relational database management system)
A relational database management system (RDBMS) is a collection of programs and capabilities that enable IT teams and others to create, update, administer and otherwise interact with a relational database. Continue Reading
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Definition
01 May 2024
database administrator (DBA)
A database administrator (DBA) is the information technician responsible for directing and performing all activities related to maintaining and securing a successful database environment. Continue Reading
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Definition
16 Apr 2024
query
A query is a question or a request for information expressed in a formal manner. Continue Reading
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Definition
04 Mar 2024
star schema
A star schema is a database organizational structure optimized for use in a data warehouse or business intelligence that uses a single large fact table to store transactional or measured data, and one or more smaller dimensional tables that store attributes about the data. Continue Reading
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Definition
10 Jan 2024
MPP database (massively parallel processing database)
An MPP database is a database that is optimized to be processed in parallel for many operations to be performed by many processing units at a time. Continue Reading
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Definition
27 Jul 2023
ACID (atomicity, consistency, isolation, and durability)
In transaction processing, ACID (atomicity, consistency, isolation, and durability) is an acronym and mnemonic device used to refer to the four essential properties a transaction should possess to ensure the integrity and reliability of the data involved in the transaction. Continue Reading
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Definition
21 Dec 2022
data source name (DSN)
A data source name (DSN) is a data structure containing information about a specific database to which an Open Database Connectivity (ODBC) driver needs to connect. Continue Reading
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Definition
24 Oct 2022
foreign key
A foreign key is a column or columns of data in one table that refers to the unique data values -- often the primary key data -- in another table. Continue Reading
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Definition
29 Jun 2022
Data Definition Language (DDL)
Data Definition Language (DDL) is used to create and modify the structure of objects in a database using predefined commands and a specific syntax. Continue Reading
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News
10 Jun 2022
Oracle sets lofty national EHR goal with Cerner acquisition
With its Cerner acquisition, Oracle sets its sights on creating a national, anonymized patient database -- a road filled with technical and legislative hurdles. Continue Reading
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News
16 Mar 2022
Oracle Multi-VM Autonomous Database lands on Exadata systems
The tech giant now enables users of the Exadata Cloud at Customer service to run multiple types of the vendor's fully managed and unmanaged databases on the same hardware. Continue Reading
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News
10 Feb 2022
Oracle Autonomous cloud database gains MongoDB API support
The tech giant continues to build out its multimodel database capabilities with the general availability of a new API for widely used MongoDB applications. Continue Reading
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Definition
12 Jan 2022
sharding
Sharding is a type of database partitioning that separates large databases into smaller, faster, more easily managed parts. Continue Reading
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News
13 Jan 2021
Oracle Database 21c brings blockchain and JavaScript
Oracle's flagship DB platform is moving beyond its roots with the 21c update, to embrace more languages and models in a bid to create a universal converged database offering. Continue Reading
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News
14 Feb 2020
Oracle Data Science efforts advance with new services
Oracle adds news new services to its cloud infrastructure platform in a bid to provide data scientists, as well as data analysts, with data management and query functionality. Continue Reading
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News
15 Jan 2020
New Oracle Enterprise Manager release advances hybrid cloud
Oracle updates its Enterprise Manager platform to version 13.4, bringing new hybrid management capabilities to database users across on-premises and cloud deployments. Continue Reading
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Feature
26 Nov 2019
Oracle looks to grow multi-model database features
Decade after decade, Oracle continues to be relevant in the database market as it pivots to include an expanding list of capabilities to serve users, notably cloud. Continue Reading
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Feature
07 Nov 2019
Oracle Autonomous Database features free DBAs from routine tasks
Oracle Autonomous Database can automate routine administrative and operational tasks for DBAs and improve productivity, but migrating to the cloud has its share of issues. Continue Reading
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News
16 Sep 2019
New cloud and on-premises options for Oracle Autonomous Database
Oracle introduced new cloud and on-premises deployment options for its namesake database and automated cloud service as Oracle OpenWorld 2019 got underway. Continue Reading
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Tip
30 Aug 2019
Consolidating databases in Oracle systems: Methods and tips
A well-planned consolidation strategy can help overcome Oracle database sprawl. But there are different ways to consolidate your databases, each with pros and cons. Continue Reading
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Feature
28 Aug 2019
How to manage Oracle database upgrades and annual releases
Oracle consultants offer tips and advice on upgrading databases, including new considerations created by the annual release schedule that Oracle is now following. Continue Reading
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Tutorial
19 Jun 2019
How to create Oracle Multitenant database user accounts
Database administrator Brian Peasland outlines the process of creating users in an Oracle Multitenant environment and details new views in the Oracle data dictionary. Continue Reading
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Tip
23 May 2019
How to connect to a pluggable database in Oracle Multitenant
Once you've created pluggable databases in an Oracle Multitenant system, the next step is to connect applications to them so they can be used. Here's how to do that. Continue Reading
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Tip
26 Apr 2019
Creating an Oracle Multitenant container database and PDBs
Database administrator Brian Peasland outlines how to create the container and pluggable databases that are at the heart of the Oracle Multitenant architecture. Continue Reading
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Feature
05 Apr 2019
Why some SAP shops move off Oracle to an SAP HANA database
While the vendors disagree on how many SAP customers have made the switch, Ferrara Candy has numbers that show a huge speed boost for its BI operations on SAP Business Warehouse. Continue Reading
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Definition
14 Mar 2019
object-oriented database management system (OODBMS)
An object-oriented database management system (OODBMS), sometimes shortened to ODBMS for object database management system, is a database management system (DBMS) that supports the modelling and creation of data as objects. Continue Reading
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Feature
13 Mar 2019
Oracle 19c database software promises stability, compatibility
Oracle Database 19c offers automatic indexing and support for external data partitions but carries upgrade issues like apps certification and index creation agreement. Continue Reading
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Feature
22 Feb 2019
First take on Oracle 19c: 6 useful enhancements for DBAs
Database administrator Brian Peasland lists some of the new and updated features coming in Oracle Database 19c that he thinks will be beneficial to Oracle users. Continue Reading
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Feature
27 Dec 2018
Key new features coming in Oracle Database 19c
With Oracle Database 19c, Oracle is aiming to boost the stability of its flagship software's latest generation. But 19c also offers DBAs a variety of added features. Continue Reading
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Tip
12 Dec 2018
Why to give third-party Oracle database monitoring tools a try
Oracle DBAs can use features in Oracle Enterprise Manager under database licenses. But third-party tools may aid efforts to monitor and tune database performance. Continue Reading
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Tip
17 Oct 2018
6 best practices on Oracle performance monitoring and tuning
Database administrators need to effectively manage Oracle Database performance to ensure an efficient processing workflow. Let this checklist be your guide. Continue Reading
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Feature
17 Oct 2018
What Oracle performance tuning tools can and can't do for DBAs
Two Oracle experts discuss the tuning and monitoring capabilities of database performance management tools -- and the ongoing role that DBAs play in the process. Continue Reading
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Tip
17 Sep 2018
Breaking down AI-infused Oracle Autonomous Cloud services
Oracle offers a variety of AI-infused cloud services that it says will automate common administrative and operational tasks for users. Here's a look at what's available now. Continue Reading
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Definition
31 Jul 2018
MySQL
MySQL is a relational database management system (RDBMS) based on SQL (Structured Query Language). Continue Reading
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News
30 Mar 2018
Oracle Autonomous Database debut heralds new cloud hopes
It wasn't the first in the cloud computing space, but Oracle is all in now. Key to the effort is a new Autonomous Database service, initially available for data warehousing uses. Continue Reading
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Tip
20 Feb 2018
How to use Oracle DBSAT to do a database security assessment
The Oracle Database Security Assessment Tool is free software that checks the security of databases. Here are the steps involved in using DBSAT to collect data and create reports. Continue Reading
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Tip
15 Dec 2017
Using Oracle 12c Unified Auditing to set database audit policies
Oracle Database 12c's built-in Unified Auditing feature streamlines the database auditing process, including creation and implementation of audit policies. Here's how that works. Continue Reading
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Tip
14 Jul 2017
Migrate an Oracle RAC database to new servers with zero downtime
Most organizations can't afford any downtime on their Oracle systems. Here's how to move RAC databases to new server nodes and still stay up and running in an Oracle cluster. Continue Reading
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Tip
14 Jun 2017
MySQL Community Server vs. Oracle MySQL databases
With various open source and commercial options available from Oracle, selecting a MySQL database can be confusing. Here's a comparison to help you decide which one makes sense for you. Continue Reading
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Tip
23 Jan 2017
Ten reasons to do an Oracle database upgrade
For every excuse made not to upgrade an Oracle database, there are overriding reasons to do so. Here are the top reasons organizations should move up to Oracle Database 12c. Continue Reading
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Tip
09 Jun 2015
Using Oracle ADDM reports to resolve SQL performance problems: Step-by step guide
Using Oracle ADDM is an effective way to resolve SQL performance problems, according to Brian Peasland. ADDM is his go-to tool for finding problem SQL statements. Continue Reading
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Feature
21 Nov 2014
How to use Patch Wizard to resolve Oracle EBS issues
Karen Brownfield shows the advantages of using Patch Wizard for Oracle EBS and how to use the Applied Patches, File History and Register Flagged Files components. Continue Reading
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Tip
25 Apr 2013
The basics of Oracle database availability
Database expert Jeff McCormick introduces some basic Oracle database availability concepts such as uptime and mean time between failures. Continue Reading
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Answer
03 Aug 2012
Calling stored procedures inside user-defined functions in Oracle Database
In this expert answer, Brian Peasland explains how to call a stored procedure inside user-defined functions in Oracle Database. Continue Reading
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Answer
07 Jul 2011
Copy Oracle Database but with no data
One reader asks how he can make a copy of his Oracle Database but not have any data in it, for test purposes. Continue Reading
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Answer
29 Jun 2010
How to add disk to ASM diskgroup with two-way mirroring
Learn how to add disk to ASM diskgroup with two-way mirroring and how to specify a failgroup in this tip from Oracle expert Brian Peasland. Continue Reading
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Answer
26 Aug 2009
How to decrypt an Oracle password using John the Ripper and checkpwd
Learn how to decrypt an Oracle password with Oracle password crackers like John the Ripper and checkpwd in this tip from an Oracle security expert. Continue Reading
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Answer
24 Jun 2009
How to use the CREATE SESSION command to track Oracle database logins
Oracle security expert Brian Peasland explains how to use the CREATE SESSION command in an Oracle audit table to track Oracle user database logins. Continue Reading
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Answer
22 Jun 2009
Can I download DBCA for Oracle Express Edition?
Understand how to install the DBCA in Oracle 10g Express Edition and why you cannot simply download DBCA in Oracle in this expert tip. Continue Reading
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Answer
20 May 2009
Can I create multiple schemas in Oracle for one user?
Want to create multiple schemas for one user in Oracle? Learn whether it's possible here. Continue Reading
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Answer
25 Mar 2009
How to solve an ORA-1555 error in the Oracle testing database
Expert Brian Peasland explains to a SearchOracle.com reader asks why the ORA-1555 error is showing in the Oracle testing database but not in production Continue Reading
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Feature
13 Mar 2009
How to use SQL Developer to run SQL statements
In this chapter, learn how to use SQL Developer to enter and execute SQL statements and scripts, work with a Snippets window, solve common syntax errors and more. Continue Reading
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Feature
12 Mar 2009
How to use SQL*Plus in Oracle
In this section, learn how to use SQL*Plus in Oracle, which may be used to run SQL statement and scripts if an Oracle database does not have SQL Developer installed. Continue Reading
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Feature
12 Mar 2009
How to work with the Oracle database home page
In this chapter, learn how to work with an Oracle database, including how to start and stop the Oracle database and use the database homepage, before learning how to use Oracle SQL Developer. Continue Reading
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Feature
12 Mar 2009
How to view and edit table column definitions
In this chapter, learn how to edit and view column names and column definitions for a table, and when to use SQL Developer to do so. Continue Reading
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Feature
12 Mar 2009
How to use SQL Developer to work with an Oracle database
In this chapter, learn how to use Oracle SQL Developer to review or modify your database design, navigate database objects and create, export and import database connections. Continue Reading
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Answer
02 Oct 2008
How to disable Oracle constraints and triggers during an import in 10g
An Oracle user asks expert Brian Peasland if constraints and triggers can be disabled on an Oracle import in Oracle 10g and how to complete this task. Continue Reading
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Answer
10 Jul 2008
Why am I receiving the ORA-12535 error when using a remote database?
An Oracle user asks why they are receiving the error ORA-12535: TNS: operation timed out when using a remote database. Continue Reading
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Answer
08 Jul 2008
Defining RTO, MTBF and MTTR
Database backup and recovery expert Brian Peasland explains the terms RTO, MTBF and MTTR. Continue Reading
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Answer
14 May 2008
What is the difference between an instance and mounting in Oracle?
An Oracle user asks what the difference is between an instance and mounting. Continue Reading
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Answer
28 Apr 2008
Import on one table from dump file
An Oracle user asks if it is possible to do an import on one table from a large dump file. Continue Reading
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Answer
22 Feb 2008
How to drop tablespace with missing datafile
Oracle expert Brian Peasland explains how to drop a tablespace with a missing datafile and recreate the tablespace. Continue Reading
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Answer
11 Jan 2008
What is the difference between obsolete and expired status?
Oracle expert Brian Peasland explains the difference between obsolete status and expired status. Continue Reading
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Answer
15 Aug 2007
LOB tables missing with exp/imp move of schema
I have a problem when moving a schema using exp/imp. After import, the tables with LOBs are missing. Continue Reading
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Answer
15 Aug 2007
Add or drop inactive online redo log files
Can we add or drop (inactive) online redo log files at the open stage? Continue Reading
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Answer
09 Aug 2007
Query on dblink returning ORA-12545 error
I have a dblink between Oracle 9i and Oracle 10g. When I execute this query sometimes I get the result, but sometimes I get the error "ORA-12545." Continue Reading
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Answer
06 Aug 2007
Restore database from backup without control files
If you just had to restore from backup and do not have any control files, how would you go about bringing up this database? Continue Reading
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Answer
21 Jun 2007
How to create an index using a procedure in Oracle
How can we create an index using a procedure? Continue Reading
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Answer
22 May 2007
How to increase SGA_MAX_SIZE in Oracle
How to increase SGA_MAX_SIZE in Oracle? I got the error "ORA-03113: end-of-file on communication channel" during startup. Continue Reading
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Answer
23 Apr 2007
When will support for Oracle 9i be discontinued?
When will general support for Oracle 9i be discontinued? Continue Reading
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Answer
12 Apr 2007
What should my global database name be?
When I type hostname it returns me this localhost.localdomain. So what should be my global database name if SID is ora9i? Continue Reading
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Answer
22 Mar 2007
Check current SCN in control file
How to check current SCN or header in the control file? Continue Reading
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Answer
27 Feb 2007
Definitions of checkpoint, PMON and SMON
What is a checkpoint? What are PMON and SMON? Continue Reading
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Answer
12 Feb 2007
Migrating database from Solaris to Linux
What is the procedure to migrate an Oracle database from a Solaris machine to Red Hat Linux 9? Continue Reading
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Answer
18 Jan 2007
Invalid stored procedures
When running an application that is connected to an Oracle server/database and trying to add rows or make a call to the DB, I am getting various errors that the stored procedures are invalid. Continue Reading
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Answer
04 Oct 2006
Non-zero values for SHARED_POOL_SIZE and JAVA_POOL_SIZE
I am getting an ORA-04031 error. I have a two-node 10g RAC cluster. If I gave both SHARED_POOL_SIZE and JAVA_POOL_SIZE values (thus overriding the defaults) how would this affect the running of the CLUSTER? Does a CLUSTER require these values to be 0? Continue Reading
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Answer
28 Aug 2006
Exporting selected procedures and functions in Oracle
How can we export selected procedures/functions/packages in Oracle? Continue Reading
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Tip
14 Aug 2006
Oracle vs. Sybase: 10 reasons to use Sybase on Linux
Despite its fall from market leadership, Sybase is still a strong enterprise offering, says database consultant Dr. Mich Talebzadeh. In this tip, he gives 10 reasons why Sybase on Linux bests other databases, particularly Oracle. Continue Reading
- Answer 16 Jun 2006
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Answer
12 Apr 2006
Check if date is greater than 2000 in PL/SQL
How to check if the date is greater than the year 2000 in PL/SQL? Continue Reading
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Answer
16 Jan 2006
Standard vs. Enterprise Editions of Oracle
What's the difference between Standard Edition and Enterprise Edition? Continue Reading
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Answer
09 Jan 2006
Easy way to import public synonyms?
Using export/import to update a development database, I normally do a schema (user) import. Is there an easy way to import public synonyms? Continue Reading
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Answer
26 Sep 2005
Converting a column from VARCHAR2 to DATE
I need to convert a date column created using data type VARCHAR2 into data type DATE. Is it possible? Continue Reading
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Definition
21 Sep 2005
field
A field is an area in a fixed or known location in a unit of data such as a record, message header, or computer instruction that has a purpose and usually a fixed size. Continue Reading
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Definition
21 Sep 2005
record
In computer data processing, a record is a collection of data items arranged for processing by a program. Continue Reading
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Answer
22 Aug 2005
Installing 32-bit and 64-bit Oracle on same machine
I have an application that does not support 64-bit Oracle. It needs to run on 32-bit Oracle. Can I install two Oracle engines (32-bit and 64-bit) on the same machine? If so, how can it be done? Continue Reading
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Answer
16 Aug 2005
VARCHAR2 vs. NUMBER
What is the correct circumstance to store a numeric string as VARCHAR2 vs. NUMBER? The response I have received before is to store all numeric strings as VARCHAR2 unless the intention is to manipulate the field mathematically; but no reason has been given. Continue Reading
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Answer
16 Aug 2005
Multiple instances on a single database
Is it possible for Oracle to have parallel servers (single database, multiple instances)? Is it impossible to have the inverse (that is, multiple databases, single instance)? Continue Reading
- Answer 31 Jan 2005
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Answer
28 Sep 2004
Purpose of roll forward and roll backward
What are rolling forward and rolling backward in backup and recovery? Continue Reading
- Answer 23 Sep 2004
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News
12 Dec 2003
Roll forward versus roll back
Database extra tip #2 from "30 tips in 30 minutes," brought to you by the IOUG. Continue Reading
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Tip
06 Aug 2003
Find users who have unlimited quota on a tablespace
Here is a query to find users that have unlimited quota on a tablespace. Continue Reading
- Answer 25 Jun 2003