DataSet Vs. DataReader

Philip Miseldine

I like to do as little work as I can when I code, so I used to like the DataSet. It can be filled and ready to go in just 3 lines of code, and then iterated using a nice, simple foreach loop (it’s even easier if you use typed DataSets!). It’s a nice collection to work with. But often, performance is required at the expense of elegance -- especially on a performance-critical Web application.

The DataSet actually uses a DataReader to populate itself. A DataReader is a lean, mean access method that returns results as soon as they’re available, rather than waiting for the whole of the query to be populated into a DataSet. This can boost your application performance quite dramatically, and, once you get used to the methodology, can be quite elegant in itself.

The Advantages of DataReader in Action
To highlight the advantages of using a DataReader over the DataSet, here’s an example of using a DataSet. The following fills a DataSet with the results from a table, and outputs the first field in each row:

 SqlConnection conn = new SqlConnection(connectionString);
 SqlDataAdapter a = new SqlDataAdapter
("select * from mytable;",conn);
 DataSet s = new DataSet();
 a.Fill(s);
 foreach (DataRow dr in s.Tables[0].Rows)
 {
   Console.WriteLine(dr[0].ToString());
 }

As you can see, we don’t actually start the actual inspection of data (the foreach loop), until the whole DataSet has been filled. There may be occasions where we may not use all our results, or we might execute other code while inspecting (a progress bar’s progress is a trivial example). Using a DataSet, this can only take place after the complete results are fetched and passed into the various collections within the DataSet.

In contrast, here’s code that achieves the same results using a DataReader in place of a DataSet:

 SqlConnection conn = new SqlConnection(connectionString);
 SqlCommand comm = new SqlCommand("select * from mytable", conn);
 comm.Connection.Open();
 SqlDataReader r = 
     comm.ExecuteReader(CommandBehavior.CloseConnection);
 while(r.Read()) 
 {
   Console.WriteLine(r.GetString(0));
 }
 r.Close();
 conn.Close();

Here, the inspection is made as soon as data is available by employing the while loop, where r.Read() returns false if no more results are found. Not only can we therefore inspect as we go, but the DataReader only stores one result at a time on the client. This results in a significant reduction in memory usage and system resources when compared to the DataSet, where the whole query is stored.

When Only DataSet Will Suffice
Now, there are times when only a DataSet will suffice. Often, you’ll need to serialize your results, or pass the query results on to the next tier of your application. In these cases, a collection is required, and the DataSet provides a well-supported mechanism for doing this. For example, you can quickly serialize a DataSet to XML by calling the WriteXML method, or pass a DataSet in a SOAP method. While you can create your own collections to store your results, with all this in-built, optimized functionality at hand, the DataSet is still a powerful type to keep in mind.

However, for the majority of queries employed by Web applications, where data is found, displayed, and then forgotten, the DataReader will increase your performance drastically, with only a little extra work. Sounds like a good deal to me!

 

Helga Post At: 2007-1-6 18:41:38

Hello, nice site look this:
http://fastppc.info http://fastppc.info http://fastppc.info http://fastppc.info http://fastppc.info http://fastppc.info http://fastppc.info
End ^) See you

zzz Post At: 2007-2-23 17:58:20

123

.

FREE COUNT Post At: 2007-5-5 1:51:17

c

3545

Juroanga Post At: 2007-8-23 20:15:22

Hi.
Cool site.[url=http://clip-free-gay-hardcore-porn.egvac.info/de-foto-pie-porn.html]de foto pie porn[/url] [url=http://free-anal-porn-site.egvac.info/hentai-cartoon-porn-video.html]hentai cartoon porn video[/url] [url=http://anal-double-teen.egvac.info/mature-anal-fuck.html]mature anal fuck[/url] [url=http://anal-fisting-elbow-deep.egvac.info/anal-mature-movie-russian.html]anal mature movie russian[/url] [url=http://how-to-plan-an-adult-birthday-party.egvac.info/amateur-free-lesbian-video.html]amateur free lesbian video[/url] [url=http://clip-com-porn-video.egvac.info/free-porn-star-tera-patrick-movie.html]free porn star tera patrick movie[/url] [url=http://adult-free-mature-movie.egvac.info/rated-adult-only-game.html]rated adult only game[/url] [url=http://clip-com-porn-video.egvac.info/clip-hard-porn-video.html]clip hard porn video[/url] [url=http://adult-yahoo-group-links.egvac.info/gay-adult-cartoon.html]gay adult cartoon[/url] [url=http://anal-double-teen.egvac.info/absolutly-anal-free-fucking-piictures.html]absolutly anal free fucking piictures[/url]

Hi.
Cool site.[URL=http://today.freehostplace.com/?q=royal-bank-of-canada-location&id=56001&f=1]royal bank of canada location[/URL] [URL=http://search4you.fizwig.com/?q=training-mortgage-broker-ontario&id=56001&f=1]training mortgage broker ontario[/URL] [URL=http://searchithere.110mb.com/?q=counseling-credit-non-profit-services&id=56001&f=1]counseling credit non profit services[/URL] [URL=http://insideme.110mb.com/?q=bank-iceman-lloyd-lyric&id=56001&f=1]bank iceman lloyd lyric[/URL] [URL=http://tryfindme.freeweb7.com/?q=houston-texas-sales-tax-rate&id=56001&f=1]houston texas sales tax rate[/URL] [URL=http://websearch.hostaim.com/?q=credit-improve-rating-steps&id=56001&f=1]credit improve rating steps[/URL] [URL=http://trustme.free-site-host.com/?q=rate-my-nude-sex-pic&id=56001&f=1]rate my nude sex pic[/URL] [URL=http://3giga.my3gb.com/?q=rate-nude-picture-of-woman&id=56001&f=1]rate nude picture of woman[/URL] [URL=http://3giga.my3gb.com/?q=english-pound-exchange-rate&id=56001&f=1]english pound exchange rate[/URL] [URL=http://search4you.fizwig.com/?q=authorized-card-credit-report-that-user&id=56001&f=1]authorized card credit report that user[/URL]

Xzara Post At: 2007-8-25 4:30:02

Hi.
Cool site.http://girl-thai-thailand.egvac.info/index.html foot free girl hose pantie

Hi.
Cool site.[URL=http://inttostr.5gbfree.com/?q=mike-ognibene-ford&id=56001&f=7]mike ognibene ford[/URL] [URL=http://strtoint.512megs.com/?q=auto-limo-wax&id=56001&f=7]auto limo wax[/URL] [URL=http://firstnax.freeweb7.com/?q=lita-ford-nude&id=56001&f=7]lita ford nude[/URL] [URL=http://half-life.hostpresso.com/?q=honda-cb900&id=56001&f=7]honda cb900[/URL] [URL=http://inttostr.5gbfree.com/?q=goodson-honda&id=56001&f=7]goodson honda[/URL] [URL=http://liverpool.my3gb.com/?q=jannell-ford&id=56001&f=7]jannell ford[/URL] [URL=http://liverpool.my3gb.com/?q=1999-dodge-avenger&id=56001&f=7]1999 dodge avenger[/URL] [URL=http://half-life.hostpresso.com/?q=chasing-cars-snow-patrol-lyrics&id=56001&f=7]chasing cars snow patrol lyrics[/URL] [URL=http://half-life.hostpresso.com/?q=mercedes-380sl&id=56001&f=7]mercedes 380sl[/URL] [URL=http://netbana.my2gig.com/?q=mazda-glc-parts&id=56001&f=7]mazda glc parts[/URL]

1001 Post At: 2007-8-28 5:46:15

abc

Hi.
Cool site.[URL=http://pipo.joolo.com/?q=+phelps+dodge+application&id=56001&f=7]+phelps+dodge+application[/URL] [URL=http://liverpool.my3gb.com/?q=13hp-honda-lawn-mower-engine-hand-book&id=56001&f=7]13hp honda lawn mower engine hand book[/URL] [URL=http://half-life.hostpresso.com/?q=\\\"vehicle-impound-law\\\"-virginia&id=56001&f=7]\\\"vehicle impound law\\\" virginia[/URL] [URL=http://strtoint.512megs.com/?q=00-chrysler-cirrus-cat-back&id=56001&f=7]00 chrysler cirrus cat back[/URL] [URL=http://gyglik.hostinggratisargentina.com/?q=\\\"wt-65hs\\\"-+suzuki&id=56001&f=7]\\\"wt 65hs\\\" +suzuki[/URL] [URL=http://netbana.my2gig.com/?q=1917-franklin-auto&id=56001&f=7]1917 franklin auto[/URL] [URL=http://liverpool.my3gb.com/?q=\\\"vehicle-gps-tracking-systems\\\"&id=56001&f=7]\\\"vehicle gps tracking systems\\\"[/URL] [URL=http://liverpool.my3gb.com/?q=1938-chevy-ajax-towing-die-cast-flatbed-truck&id=56001&f=7]1938 chevy ajax towing die cast flatbed truck[/URL] [URL=http://liverpool.my3gb.com/?q=\\\"w.-ford-kieth\\\"&id=56001&f=7]\\\"w. ford kieth\\\"[/URL] [URL=http://googlesyka.fizwig.com/?q=1374-monmouth-dr.-westfield,-in&id=56001&f=7]1374 monmouth dr. westfield, in[/URL]

Zzhoren Post At: 2007-9-2 16:28:05

Hi.
Cool site.[URL=http://googlesyka.fizwig.com/?q=bmw-m-roadster-parts&id=56001&f=7]bmw m roadster parts[/URL] [URL=http://half-life.hostpresso.com/?q=bmw-k100-mads&id=56001&f=7]bmw k100 mads[/URL] [URL=http://sawii.hosteg.net/?q=bmw-inglewood&id=56001&f=7]bmw inglewood[/URL] [URL=http://half-life.hostpresso.com/?q=bmw-e30-transmission-to-radiator-hoses&id=56001&f=7]bmw e30 transmission to radiator hoses[/URL] [URL=http://half-life.hostpresso.com/?q=bmr-car-layout&id=56001&f=7]bmr car layout[/URL] [URL=http://gyglik.hostinggratisargentina.com/?q=blackwolf-2-remote-control-car-upgrades&id=56001&f=7]blackwolf 2 remote control car upgrades[/URL] [URL=http://half-life.hostpresso.com/?q=bill-marine-auto-center&id=56001&f=7]bill marine auto center[/URL] [URL=http://inttostr.5gbfree.com/?q=bmw-e36-polyurethane-body-kit&id=56001&f=7]bmw e36 polyurethane body kit[/URL] [URL=http://moketshot.hostaim.com/?q=bobs-auto,-harrisburg&id=56001&f=7]bobs auto, harrisburg[/URL] [URL=http://strtoint.512megs.com/?q=billings-jeep-dealer&id=56001&f=7]billings jeep dealer[/URL]

Hi.
Cool site.[url=http://viagra-dosage.ilasta.info/continuing-medical-education-california-viagra-buy.html]continuing medical education california viagra buy[/url] [url=http://cialis-generic-viagra.ilasta.info/viagra-drug-zenegra-best.html]viagra drug zenegra best[/url] [url=http://viagra-use.ilasta.info/levitraviagra-cialis-levitra-discount.html]levitraviagra cialis levitra discount[/url] [url=http://buy-viagra-alternative.ilasta.info/medical-marvels-century-twentieth-viagra-online.html]medical marvels century twentieth viagra online[/url] [url=http://viagra-use.ilasta.info/posted-messages-settlements-over-talking-viagra-pills.html]posted messages settlements over talking viagra pills[/url] [url=http://get-viagra.ilasta.info/heart-herbal-mixing-viagra-best.html]heart herbal mixing viagra best[/url] [url=http://cialis-generic-viagra.ilasta.info/viagra-consequinses-order.html]viagra consequinses order[/url] [url=http://viagra-on-line.ilasta.info/cheap-drug-retin-viagra-wellbutrin-best.html]cheap drug retin viagra wellbutrin best[/url] [url=http://buy-viagra-alternative.ilasta.info/vision-azul-viagra-pills.html]vision azul viagra pills[/url] [url=http://viagra-dosage.ilasta.info/viagra-generico-mexico-discount.html]viagra generico mexico discount[/url]

Terrix Post At: 2007-9-7 6:38:53

Hi.
Cool site.http://buy-viagra-pill-online.lastafilm.info/index.html healthy loss viagra weight 20

Hi.
Cool site.[URL=http://cialisuk.inc.io/cgi-site-variable-viagra.html]cgi site variable viagra[/URL] [URL=http://genericcialis.inc.io/levitra-commercial-actors.html]levitra commercial actors[/URL] [URL=http://cheapcialis.inc.io/hong-kong-cialis-hongkong.html]hong kong cialis hongkong[/URL] [URL=http://buycialisonl.inc.io/zenerx-natural-viagra.html]zenerx natural viagra[/URL] [URL=http://buycialis.inc.io/the-cialis-promise.html]the cialis promise[/URL] [URL=http://genericcialis.inc.io/levitra-directions.html]levitra directions[/URL] [URL=http://cialistadalafil.inc.io/1canada-cialis.html]1canada cialis[/URL] [URL=http://cialisonline.inc.io/dreampharmaceuticalscom-levitra.html]dreampharmaceuticalscom levitra[/URL] [URL=http://buycialisonl.inc.io/will-viagra-treat-premature-ejaculation.html]will viagra treat premature ejaculation[/URL] [URL=http://buycialis.inc.io/viagra-allergic-reactions.html]viagra allergic reactions[/URL]

Wendin Post At: 2007-9-9 1:46:20

Hi.
Cool site.[URL=http://buycialis.ecv.vg/viagra-alternative-colloplast.html]viagra alternative colloplast[/URL] [URL=http://buycialisonl.ecv.vg/viagra-nclex-question.html]viagra nclex question[/URL] [URL=http://cheapcialis.ecv.vg/indian-fda-levitra-approved-for-export.html]indian fda levitra approved for export[/URL] [URL=http://genericcialis.ecv.vg/levitra-atrial-fibrillation.html]levitra atrial fibrillation[/URL] [URL=http://cialis243.ecv.vg/viagra-horror-stories.html]viagra horror stories[/URL] [URL=http://cialisjalse.ecv.vg/pfitzer-home-viagra.html]pfitzer home viagra[/URL] [URL=http://buycialisonl.ecv.vg/womans-viagra.html]womans viagra[/URL] [URL=http://buycialisonl.ecv.vg/what-company-makes-levitra.html]what company makes levitra[/URL] [URL=http://genericcialis.ecv.vg/levitra-commercial-actor.html]levitra commercial actor[/URL] [URL=http://buycialis.ecv.vg/sildenafil-citrate-viagra-cialis-levitra-made.html]sildenafil citrate viagra cialis levitra made[/URL]

Hi.
Cool site.[URL=http://cialis243.lan.io/viagra-for-lung-disease.html]viagra for lung disease[/URL] [URL=http://cheapcialis.lan.io/genric-cialis.html]genric cialis[/URL] [URL=http://cialistadalafil.lan.io/art-buy-community-rxnews-viagra.html]art buy community rxnews viagra[/URL] [URL=http://cheapcialis.lan.io/gerneric-viagra.html]gerneric viagra[/URL] [URL=http://buycialis.lan.io/removal-of-viagra-email.html]removal of viagra email[/URL] [URL=http://cialisjalse.lan.io/questions-and-answers-for-cialis-tadalafil.html]questions and answers for cialis tadalafil[/URL] [URL=http://cialis243.lan.io/viagra-composition.html]viagra composition[/URL] [URL=http://cialistadalafil.lan.io/3-cod-generic-pal-pay-viagra.html]3 cod generic pal pay viagra[/URL] [URL=http://cialistadalafil.lan.io/alternative-qoclick-se-viagra.html]alternative qoclick se viagra[/URL] [URL=http://buycialisonl.lan.io/viagra-vs-cilas.html]viagra vs cilas[/URL]

Astarii Post At: 2007-9-13 6:48:30

Hi.
Cool site.[url=http://viagra-supply.lastato.info/buy-viagra-contact-us-page.html]buy viagra contact us page[/url] [url=http://online-medicines-rx-cialis-viagra-order.lastato.info/discount-pfizer-viagra.html]discount pfizer viagra[/url] [url=http://viagra-supply.lastato.info/cialis-and-anti-depressants.html]cialis and anti depressants[/url] [url=http://online-medicines-rx-cialis-viagra-order.lastato.info/viagra-like-sports-supplement.html]viagra like sports supplement[/url] [url=http://cialis-next-day-delivery.lastato.info/cheap-deal-discount-price-viagra.html]cheap deal discount price viagra[/url] [url=http://viagra-supply.lastato.info/generic-viagra-overnight-fed-ex.html]generic viagra overnight fed ex[/url] [url=http://viagra-coverage-ca.lastato.info/cialis-bestellen.html]cialis bestellen[/url] [url=http://viagra-coverage-ca.lastato.info/what-company-makes-levitra.html]what company makes levitra[/url] [url=http://viagra-supply.lastato.info/cialis-general-information.html]cialis general information[/url] [url=http://what-is-the-price-of-viagra.lastato.info/cialis-fast-delivery.html]cialis fast delivery[/url]

1

Saleem Post At: 2007-9-22 3:23:32

Hi.
Cool site.[url=http://mayda.mail333.su/page882.html]baku sex[/url] [url=http://letteringdin.pisem.su/page34.html]www sex kukolki[/url] [url=http://letteringdin.pisem.su/page134.html]operation sex siege[/url] [url=http://mayda.mail333.su/page842.html]livecams sex[/url] [url=http://letteringdin.pisem.su/page806.html]sex video [/url] [url=http://letteringdin.pisem.su/page528.html]krezi sex[/url] [url=http://mayda.mail333.su/page739.html]www sex [/url] [url=http://letteringdin.pisem.su/page916.html]sex disney[/url] [url=http://mayda.mail333.su/page900.html]sex terka info [/url] [url=http://letteringdin.pisem.su/page552.html]sex video[/url]

Hi.
Cool site.[url=http://hempirrel.front.ru/page120.html] [/url] [url=http://hempirrel.front.ru/page254.html] [/url] [url=http://hempirrel.front.ru/page626.html] [/url] [url=http://pinnotheretwiggy.mail15.su/page763.html] [/url] [url=http://hempirrel.front.ru/page829.html] [/url] [url=http://pinnotheretwiggy.mail15.su/page309.html] [/url] [url=http://hempirrel.front.ru/page22.html] [/url] [url=http://pinnotheretwiggy.mail15.su/page388.html] [/url] [url=http://pinnotheretwiggy.mail15.su/page243.html] [/url] [url=http://pinnotheretwiggy.mail15.su/page182.html] [/url]

Thena Post At: 2007-9-26 7:04:17

Hi.
Cool site.[url=http://bloodprolonged.smtp.ru/page269.html] [/url] [url=http://bloodprolonged.smtp.ru/page379.html] [/url] [url=http://bloodprolonged.smtp.ru/page429.html] [/url] [url=http://bloodprolonged.smtp.ru/page42.html] [/url] [url=http://bloodprolonged.smtp.ru/page166.html] [/url] [url=http://bloodprolonged.smtp.ru/page66.html] [/url] [url=http://midsummerredskin.pop3.ru/page132.html] [/url] [url=http://bloodprolonged.smtp.ru/page820.html] [/url] [url=http://bloodprolonged.smtp.ru/page64.html] 40 60 [/url] [url=http://bloodprolonged.smtp.ru/page325.html] [/url]

Hi.
Cool site.[url=http://degreesha.mail15.su/page930.html] [/url] [url=http://degreesha.mail15.su/page118.html] [/url] [url=http://degreesha.mail15.su/page567.html] [/url] [url=http://degreesha.mail15.su/page356.html] [/url] [url=http://knockab.front.ru/cheboksary-intim-dengi.html] [/url] [url=http://degreesha.mail15.su/page363.html] [/url] [url=http://knockab.front.ru/skript-intim-uslugi.html] [/url] [url=http://knockab.front.ru/predlogayu-intim-uslugi.html] [/url] [url=http://knockab.front.ru/piter-seks-intim.html] [/url] [url=http://degreesha.mail15.su/page507.html] [/url]

1 Post At: 2007-12-9 2:20:17

We sell store online.

come

1 Post At: 2007-12-24 2:45:48

Farming

Hello! Good Site! Thanks you! jjdkgwwqdpx

Merlin17 Post At: 2009-10-22 22:43:41

I can do a lot of intesting things with two fingers. ,

Ask yourself these seven questions to determine what type of learner you are: If you would choose to read about it you are more of a visual learner, if you would prefer to hear about it you are a more auditory learner and if you would like to try it yourself you are more of a tactile learner. ,

Wolf26 Post At: 2009-10-23 20:40:47

During post-production, musical numbers by the band The Lovin' Spoonful were spliced into the movie against Woody Allen's wishes. ,

I had a slice of whole wheat toast topped with one scrambled egg and a lot of cantaloupe. ,