Delete a table

Be careful to use this query
DROP TABLE YourTable;
Drop a table and related references
DROP TABLE YourTable CASCADE CONSTRAINT;

Get source code/script of a view

You can use this query to get the script of your view quickly.

SELECT TEXT
FROM all_views
WHERE VIEW_NAME = 'Your View Name'

Get objects created/modified recently

SELECT OBJECT_NAME,
TO_CHAR(CREATED,       'DD-Mon-RR HH24:MI') CREATE_TIME,
TO_CHAR(LAST_DDL_TIME, 'DD-Mon-RR HH24:MI') MOD_TIME,
STATUS
FROM   USER_OBJECTS
WHERE  SYSDATE - LAST_DDL_TIME < 7

SQL Sever queries take most I/O

SELECT TOP 100
    (total_logical_reads + total_logical_writes) / qs.execution_count AS average_IO,
    (total_logical_reads + total_logical_writes) AS total_IO,
    qs.execution_count AS execution_count,
    SUBSTRING (qt.text,qs.statement_start_offset/2,
         (CASE WHEN qs.statement_end_offset = -1
            THEN LEN(CONVERT(NVARCHAR(MAX), qt.text)) * 2
          ELSE qs.statement_end_offset END - qs.statement_start_offset)/2) AS indivudual_query,
    o.name AS object_name,
    DB_NAME(qt.dbid) AS database_name
FROM sys.dm_exec_query_stats qs
    CROSS APPLY sys.dm_exec_sql_text(qs.sql_handle) as qt
    LEFT OUTER JOIN sys.objects o ON qt.objectid = o.object_id
WHERE qt.dbid = DB_ID()
ORDER BY average_IO DESC;

Queries taking longest elapsed time

Sometimes, you need to determine which queries take a lot of time to run. In this case, you can use this query to check.

SELECT TOP 100 qs.total_elapsed_time / qs.execution_count / 1000000.0 AS average_seconds,
  qs.total_elapsed_time / 1000000.0 AS total_seconds,
  qs.execution_count,
  SUBSTRING (qt.text,qs.statement_start_offset/2,
 (CASE WHEN qs.statement_end_offset = -1
          THEN LEN(CONVERT(NVARCHAR(MAX), qt.text)) * 2
        ELSE qs.statement_end_offset END - qs.statement_start_offset)/2) AS individual_query,
  o.name AS object_name,
  DB_NAME(qt.dbid) AS database_name
FROM sys.dm_exec_query_stats qs
  CROSS APPLY sys.dm_exec_sql_text(qs.sql_handle) as qt
  LEFT OUTER JOIN sys.objects o ON qt.objectid = o.object_id
WHERE qt.dbid = DB_ID()
ORDER BY average_seconds DESC;

Rename a table

Rename EMP to EMPLOYEE:
RENAME EMP TO EMPLOYEE;

Check active session

SELECT *
FROM v$session
WHERE STATUS = 'ACTIVE'
AND OSUSER = 'Your OSUSER'

10 Things Small Businesses Must do to Protect & Secure Data

In this podcast, Donna Childs of Prepared Small Business, discusses some best practices to help small businesses keep their information secure, protected, and well-managed.
Read here
Source: Symantec Corporation

SQL Server 2008 and using Transact SQL (TSQL)

How To Become a Database Administrator