Skip to main content

What is nolock in SQL Server

Image
By
Nolock is nothing but it decrease the concurrency of busy system.

When there is nolock for data then that data can be taken by another transaction.

Reads the dirty page irrespective to the isolation level. (Not in all scenario).

NOLOCK is used in SELECT queries as query hint, it functions the same way as READ UNCOMITTED isolation level where dirty reads are possible. It is highly recommended for all applications where Performance and concurrency is vital and dirty reads takes a backseat. Like in non-banking and web based applications it is much used, and also in internal web applications used in back-office by multiple users. We can use NOLOCK in all non-financial and non-payment related transactions most of the times. Every domain and case needs to be verified.
Labels:

Comments

Post a Comment

Please avoid link comments

Popular posts from this blog

Song Aankhen Khuli Ho lyrics notation

By
Song : Aankhen Khuli Ho Movie: Mohabbatein Notes used : W=>Western - C D E F G- A- B-/ H=>Hindustani - S R G M P- D- N- ( Here for western, G=G-, A=A-, & B=B- ) ( For hindustani, P=P-, D=D-, & N=N- ) Song I : Aankhen Khuli...Ho Ya.. Ho Bandh W=> A.... C... B..C.. E.. E...... A... A.... H=> D... S... N..S.. G G....... D... D.... Deedaar Un Ka Ho.o.taa Hai.. W=> A...B....A....D.BAG....ADB... H=> D...N...D.....R.NDP...DRN... Kaise Kahoon Main O..Yaaraa W=> B..D.. D....E.... D.....C..C..C... H=> N..R.. R....G... R.....S..S..S..... Ye Pyaar Kaise Hota Hai W=> E...B.....DB...AG...B..AA H=> G...N....RN...DP...N...DD (Tururu ru ru, ru ru rururu ru......) W=> AA...GA...BCE..., B...DB..GA H=> DD...PD...NSG..., N..RN.. PD Song II: Aa.aj He Kisi..par Yaa.ro.on..., Marke De..Khe..gein Hum W=> E....FEDCBABC.D.. D D......., G A B C.... E.......D...D..... H=> G....MGRSNDNS.R. R R......., P D N S.....G........R...R.... Pyaar Ho...
1 comment
Read more

All songs notation and chords at one place

By
Song : O Saathi Re Film : Mukhathar Ka Sikkandhar Uses : C D D# E G A Note : The numbers at the end of the lines indicate line numbers. Pallavi: O saathi re, tere binaa bhi kya jina, tere binaa bhi kya jina A- C D D#....,D D C DD E...C..CA-...,D D C DD E...CC.......1 Play line 1 again phulon men khaliyon men sapnom ki galiyon men GGG...GAGE.. GGG G A G E.................................................2 tere bina kuchh kahin naa E A G E D C D D#.......................................................................3 tere binaa bhi kya jina, tere binaa bhi kya jina D D C DD E....C..CA-..., D D C DDE....CC.............................4 Charanam: har dhadkan men, pyaas hai teri, sanson men teri khushboo hai CCC C D C A-, CCC C D C A-, DDD DED CD EE.. CCCC......................5 is dharthi se, us ambar tak, meri nazar men tu hi tu hai CCC C D C A-, CCC C D C A-, DDD DED CD EE.. CCCC......................6 pyaar yeh tute naa GGG... GAG D#......E............................
Read more

PHP Tips-Getting the nodes list of xml doument with responseXml in ajax ,call image save in database,time difference etc

By
Getting the nodes list of xml doument with responseXml in ajax var obj = ""; function callAjaxObj() { try { obj = new XMLHttpRequest(); } catch(e) { try { obj = new ActiveXObject("Msxml2.XMLHTTP"); } catch(e) { try { obj = ActiveXObject("Microsoft.XMLHTTP"); } catch(e) { alert("your browser doesn't support ajax"); return false; } } } } function testResponseXml() { callAjaxObj(); obj.open("get","sample.xml",true); obj.onreadystatechange=function() { if(obj.readyState==4) { var doc = obj.responseXML.documentElement; //var doc = obj.responseXML; alert(doc.getElementsByTagName('user').length); } } obj.send(null); } Example of calender script in PHP calender script in PHP echo " $title $year "; echo "SMTWTFS"; $day_count = 1; echo ""; while ( ...
Read more