How to take backup of a oracle schema

How to take backup of a oracle schema
You can use Export/Import OR Data pump.
For export(this command can be used to generate a backup file on the client machine)
exp user/password@database owner=user file=datafile.dmp log=logfile.log
where
database=db entry from tnsnames.ora,user=user-id to connect with,
password=password of the user connected with, 
owner=schema which needs to be exported,
more options can be expplored by
exp help=y

Read more

ORA-01555 “snapshot too old”

How to avoid ORA-01555 “snapshot too
old" error?

From the developer’s
perspective:

Restructure your PL/SQL code to
avoid fetching across commits that cause the ORA-01555 error.

One possible reason can be if we
leave the cursor open for fetching while
we are processing and committing data changes for a long time.


Read more

Installing sample schema in Oracle 10g R2

Installing sample schemas(HR,OE,PM etc…) in Oracle 10g R2

1. Get the companion disk for Oracle 10g from oracle.com

2. Unzip and extract the contents on the server

3. Run the Oracle Universal Installer to install the components, choose "Oracle database products"
Read more

Troubleshooting Import of Oracle Dump Files

A no. of errors are encountered while importing dump files in Oracle database.

Some of them are due to

1. Tablespace not found.
2. User/Role not found.
3. Incorrect database charset

If correct parameters are not provided to the person doing the import, it a more of HIT/TRIAL methdology.

Read more

Adding sequence to a table

This TIP can be used to add a sequence in a column for a table The syntax for creating a sequence is  CREATE SEQUENCE sequence_name    MINVALUE…

Oracle SQL tuning- Identifying bottlenecks

    To start with PL/SQL or SQL tuning the first step should be to identify the bottleneck in the whole code. Idetifying individual SQL queries that are giving problems is no difficult task.
But identifying some PL/SQL block can be a difficult job.

Read more