How to find database restore history from MSDB?

You can use the below query to get the particular database restore history. 

  



SELECT TOP 10 *

FROM restorehistory WITH (nolock)WHERE (destination_database_name = 'Database Name')ORDER BY restore_date DESC

All Databases

SELECT TOP 10 * FROM restorehistory WITH (nolock)ORDER BY restore_date DESC

How to improve communication skills & Support Service

As DBA comes under the support industry, it is extremely important for DBAs to improve communication skills. As we are working production servers and backend, it is extremely important for us to communicate properly. 

• Please take care of the below points to improve your written communication skill. 


•  When you reply all, make sure to move names from TO to CC and CC to TO list according to whom you are writing emails

• Be concise and to the point. Use simple English.


• Avoid the use of slang words/abbreviations


• Use proper spelling, grammar & punctuation


• Do not write in CAPITALS. CAPITALS indicate that we are shouting.


• Numbers should be expressed as words when the number is less than 10 or is used to start a sentence (example: Ten years ago, my brother and I…). The number 10, or anything greater than 10, should be expressed as a figure (example: My brother has 13 Matchbox cars.)


• You should just mention the name instead of Hi Jugal.As we are working as support team, use `We` instead of `I`. For example; Jugal instead of Hi Jugal


• You should change the text in the Subject line during reply emails if it is not relevant.


• If you are asking for something in the email, you should ask them first and then mention why you need that.

• Don’t write open ended email to user


• If you are not sure for any support request, please ask end user for more inputs on particular request.


• Inform your team regarding any conversation with client through chat or voice call


• Update your work log every day


• If you are not sure for any resolution steps, discuss it with your team and then provide it to client


• When sending large attachments, always "zip" or compress them before sending.


• Always include subject in your mail body.


• Don’t send email to any account using your client account


• Discuss as much as possible with your client


• Grab as much as possible knowledge of the client process/environment

Save Water, Save Life and Save the Workl

How to improve TempDB performance?

How to improve TempDB performance? 

1) TempDB file size and physical placement on harddrive can affect the performance of a system

2) Set the tempdb recovery model to simple 

3) Do the capacity planning of the TempDB database and pre allocate the appropriate size to MDF files, which will improve performance for allocating size 

4) Put TempDB on fast I/O System 

5) Create as many tempdb data files by considering the number of cpu 

6) make all the tempdb data file size same

Troubleshoot Suspect Database Issue

Problem

How to troubleshoot suspect database problem? How to bring it back online? What are the do you need to perform once the database is online?



Solution

Step 1: Bring the database online using below script

USE Master

GO

 

-- Determine the original database status

SELECT [Name], DBID, Status

FROM master.dbo.sysdatabases

GO

 

-- Enable system changes

sp_configure 'allow updates',1

GO

RECONFIGURE WITH OVERRIDE

GO

 

-- Update the database status

UPDATE master.dbo.sysdatabases

SET Status = 24

WHERE [Name] = 'SuspectedDatabaseName'

GO

 

-- Disable system changes

sp_configure 'allow updates',0

GO

RECONFIGURE WITH OVERRIDE

GO

 

-- Determine the final database status

SELECT [Name], DBID, Status

FROM master.dbo.sysdatabases

GO

Step 2: Check for database corruption. This is very important step please execute it.

• DBCC CHECKDB - Validate the overall database integrity


• DBCC CHECKCATALOG - Validate the system catalog integrity


• DBCC CHECKTABLE - Validate the integrity for a single table

Step 3: To resolve the corruption issue, please execute below commands

• Drop and Recreate Index(es)


• Move the recoverable data from an existing table to a new table


• Update statistics


• DBCC UPDATEUSAGE


• sp_recompile

Step 4: Repeat Step 2 to validate all the corruption occurred

DRBD, Heartbeat and MySQL

The easiest solution to implement clustering in MySQL is DRBD and Heartbeat.

DRBD: The Distributed Replicated Block Device (DRBD) is a software-based, shared-nothing, replicated storage solution mirroring the content of block devices (hard disks, partitions, logical volumes etc.) between servers.

DRBD mirrors data

• In real time. Replication occurs continuously, while applications modify the data on the device.


• Transparently. The applications that store their data on the mirrored device are oblivious of the fact that the data is in fact stored on several computers.


• Synchronously or asynchronously. With synchronous mirroring, a writing application is notified of write completion only after the write has been carried out on both computer systems. Asynchronous mirroring means the writing application is notified of write completion when the write has completed locally, but before the write has propagated to the peer system

You can download DRDB from below site

http://www.drbd.org/download/packages/

Memcached & MySQL

memcached (pronunciation: mem-cash-dee.) is a general-purpose distributed memory caching system that was originally developed by Danga Interactive for LiveJournal, but is now used by many other sites. It is often used to speed up dynamic database-driven websites by caching data and objects in memory to reduce the number of times an external data source (such as a database or API) must be read. Memcached is distributed under a permissive free software license. Memcached lacks authentication and security features, meaning it should only be used on servers with a firewall set up appropriately. By default, memcached uses the port 11211. Among other technologies, it uses libevent. Memcached's APIs provides a giant hash table distributed across multiple machines. When the table is full, subsequent inserts cause older data to be purged in least recently used (LRU) order. Applications using memcached typically layer memcached requests and additions into core before falling back on a slower backing store, such as a database. You can download memcached API from http://www.danga.com/memcached/

 

How to search error from SQL Server error log or SQL Server Agent Log?

How to search error from SQL Server error log or SQL Server Agent Log?

We can find the particular error or information from error log by passing below parameters to XP_ReadErrorLog extended procedure.

EXEC sys.xp_readerrorlog @p1,@p2,@p3,@p4

@P1 = Value of error log file you want to read: 0 = current, 1 = Archive #1, 2 = Archive #2, etc...

@P2 = Log file type: 1 or NULL = error log, 2 = SQL Agent log

@P3 = Search string 1: String one you want to search for

@P4 = Search string 2: String two you want to search for to further refine the results

Please note all the parameters are optional.

Error 18456, Severity 14: Login Failed States

Error 18456, Severity 14: Login Failed States
Login Failed states summary
State	Description
1	Only state returned in SQL 2000. Server is in Single-User Mode (2005).
2 and 5	Invalid User Id
6	Attempt to use a windows login name with SQL Authentication
7	Login disabled and password mismatch
8	Password mismatch
9	Invalid Password
10	Read Ref Link #2
11 and 12	Valid login but server access failure; Default Database access failure. Or Initial database connection failure in connection string.
13	SQL Server service paused
16	User doesn't have permission to target database
18	Change password required
23	Server in process of shutting down, and user attempted to login.
27	Initial database could not be determined for session
38	Initial database could not be determined for session (SQL 2008)
40	Default database could not be accessed (SQL 2008)