What is a Bind Variable? -It is a placeholder for a value .It is replaced by actual value when the SQL statement is executed-In PL/SQL it is called a local or global variable. DECLARE l_empl_id DEPT.emp_id%TYPE; BEGIN select first_name from DEPT where id = l_empl_id; END; -in SQL*Plus it is a variable variable a number BEGIN […]
How to Install Oracle Express Edition for SQL Practice
We have to practice the sql statement to become well versed with syntax, restrictions and expression. Oracle Express Edition for windows is a good environment to do practice on your laptop or Desktop . I am going to provide you the step by step installation guide for that. Step by Step Oracle Express Edition Installation […]
Oracle Data types
When you create an Oracle table, you have to specify a datatype for each column, which is associated with a specific storage format, constraints, and a valid range of values. The knowledge of data types is necessary before creating the table. Here in this article, we will see important oracle data types which you will […]
ORA-00054: resource busy and acquire with NOWAIT specified
ORA-00054: resource busy and acquire with NOWAIT specified is a common error seen in Oracle Database Reference: Oracle documentation This generally happens when you try to execute a DDL on the table which is locked by transaction .It also happens if select for update statement is executed with NOWAIT option Example SQL> alter table emp add […]
ORA-01017: invalid username/password; logon denied Tips
ORA-01017 is one of the common error seen while connecting to oracle database. Here is what documentation says about this error Here are the checklist to run to resolve the ORA-01017: invalid username/password 1)The main issue with an ORA-01017 error is an invalid user ID and passwords combination. You have to make sure ,you are […]
how to check degree of parallelism in oracle & Default Parallelism
how to check degree of parallelism in oracle Suppose we execute the below query in Oracle database select /*+ PARALLEL(JN) */ count(*) from ar.RA_INTERFACE_LINES_ALL jn; Here we can see , we have not specified the degree of the parallelism.Now there are two cases i. if we have defined degree at the table level, then that […]