Category Archives: Oracle

ORACLE TUTORIALS

Oracle is most widely used Oracle database in the world. It has the capacity to handle large database and high transaction

Here I am presenting the Oracle tutorials on Various Oracle products

  1. Oracle database
  2. Oracle sql/plsql
  3. Oracle application
  4. Weblogic
  5. Performance tuning.

These articles will be  really help in understanding the oracle products and getting started on Oracle system

How to Solve ORA-00942 table or view does not exist

ORA-00942 is one of the many errors which Oracle developer ,DBA often gets. Lets first look at the OERR output Cause: The table or view entered does not exist, a synonym that is not allowed here was used, or a view was referenced where a table is required. Existing user tables and views can be listed by querying the data dictionary. Certain privileges may be required … Continue reading How to Solve ORA-00942 table or view does not exist »

How to resolve the ORA-00936 missing expression

Last updated on July 12th, 2018 at 05:51 pmDescription : ORA-00936 missing expression is one of the common error everybody working in Oracle Sql must have faced some time. This generally happens when you omit important thing in the Sql statement i.e you left out an important chunk of what you were trying to run Reference : Oracle documentation Cause This Oracle error is mainly related … Continue reading How to resolve the ORA-00936 missing expression »

ORA-01017: invalid username/password; logon denied Tips

Last updated on July 13th, 2018 at 05:20 amORA-01017  is one of the common error seen in PLSQL programs. Here is what documentation says about this error Here are the checklist to run to resolve the ORA-01017 error The main issue with an ORA-01017 error is an invalid user ID and passwords combination.  You have to make sure ,you are entering the right password Incase … Continue reading ORA-01017: invalid username/password; logon denied Tips »

How to resolve ORA-29913 with external tables

Last updated on July 13th, 2018 at 09:00 amORA-29913 is one of the common error when working with external tables in Oracle database. We would be looking at various ways the error can be produced and what can be done to resolve the error External File not found or permission incorrect SQL> select * from Scott.example_external_table; select * from example_external_table * ERROR at line 1: … Continue reading How to resolve ORA-29913 with external tables »

Sql Subqueries : Single, Multiple, Scalar and Correlated

Sql SubQueries 1) A Subquery or Nested query is a query within another SQL query and embedded within the WHERE clause. A subquery is a query within a query 2) A subquery is used to return data that will be used in the main query as a condition to further restrict the data to be retrieved. 3) Subqueries answer the queries that have multiple parts. … Continue reading Sql Subqueries : Single, Multiple, Scalar and Correlated »

What are Oracle Joins (Sql Joins)?

Sometimes you need to display data from multiple tables. In order to perform that you need to link one table to another table.There are various ways in which we can obtain data from Multiple tables.Here I would be focusing on Oracle Joins.This is valid for in general any Sql Joins also Oracle Joins A Oracle Joins ( Sql Joins) is a query that combines rows from … Continue reading What are Oracle Joins (Sql Joins)? »

what is materialized views in oracle?

Last updated on June 23rd, 2018 at 07:11 amWhat is materialized views in oracle A materialized view is a database object that contains the results of a query. It is different from simple view .These materialized view have data stored and when you query the materialized view,it returns data from the data stored. The FROM clause of the query can name tables, views, and other … Continue reading what is materialized views in oracle? »

How to resolve ORA-00904: invalid identifier

ORA-00904: invalid identifier is one of the common error seen. Reference: Oracle documentation One of the most common cause of this error Invalid identifier means the column name entered is either missing or invalid. It also Some time comes  when you used reserved word in Oracle database. Check List to resolve the ORA-00904 error  It comes when you put extra comma in the create table … Continue reading How to resolve ORA-00904: invalid identifier »

How to use Oracle SQL*Plus

Here in this post,I would be giving introduction to Oracle sqlplus  which is Oracle tools to connect to database  and how to download Oracle sqlplus Oracle SQL*Plus What is Oracle Sql*plus: 1) SQLPlus, widely used by DBAs and developers, is a powerful and straightforward tool from Oracle to interact with the database. 2) SQLPlus has its own formatting commands to make your queries look better, … Continue reading How to use Oracle SQL*Plus »

Useful Unix/Linux command for Oracle DBA

Last updated on June 21st, 2018 at 07:03 am Oracle DBA need to operate on Unix/Linux/Solaris/AIX Operating system. He has to locate various file, process, kill session ,clear directories, schedule cron and various other activities. Here in this article I am trying to give some Useful Unix command for Oracle DBA  to help them in day-to-day activities.These same commands are applicable for Linux also. Hope you … Continue reading Useful Unix/Linux command for Oracle DBA »

how to write sql queries

Last updated on June 21st, 2018 at 05:59 pm What is SQL? Relational Database Management system(RDBMS) contains many tables . These tables are the basic storage in Database. Tables contains the information about something in the real world for example customers ,employees ,deptTables in the database contain zero to many rows. SQL which stands for “Structured Query Language” which is pronounced as “SQL” or “sequel … Continue reading how to write sql queries »

ORA-00257: archiver error. Connect internal only, until freed.

Last updated on July 13th, 2018 at 09:38 amORA-00257 is one of the commonest error in Oracle DBA life. He/She often has to deal with it.Database almost got frozen because of it and all transaction get stopped .Let us see how to deal with ORA-00257 error Error Message   ORA-00257: archiver error. Connect internal only, until freed. As per The oerr ORA-00257 error means ORA-00257: … Continue reading ORA-00257: archiver error. Connect internal only, until freed. »