SQL Server useful but less known features

  • Posted on: 2 November 2016
  • By: Michał Turecki

  1. Checking who is connected to the database

    sp_who

    SELECT
    NULL as [Connections by Database],
    [host_name] AS [Client Machine],
    db.name AS [Database],
    [program_name] AS [Client Program],
    COUNT(*) AS [Open Connections]
    FROM sys.dm_exec_sessions s (nolock)
    LEFT JOIN sys.dm_exec_requests r (nolock) ON r.session_id = s.session_id
    LEFT JOIN sys.databases db (nolock) ON db.database_id = r.database_id
    WHERE s.session_id >= 50 -- Ignore SQL Server processes
    GROUP BY [host_name], db.name, [program_name]
    ORDER BY [Client Machine], [Database], [Client Program]

  2. Adjusting connection pooling settings

    By default pool size is 100 per database with a command timeout (effectively a connection timeout) of 15 seconds. To increase add following to the connection string:

    Connection Timeout=30;Pooling='true';Max Pool Size=200

  3. Checking the size of column's contents

    To check how much data the column contains:

    SELECT *, DATALENGTH([column]) AS ColumnSizeInBytes FROM table

  4. Using SQL Server profiler

    Profiler is a powerful way to debug application performance problems, to check query execution time. If you're developing any application using SQL Server as a database, running it at least once for every application release can help with pinpointing possible performance issues. Remember the rule - there should be a constant number of queries regardless of the amount of records fetched - that way application will scale better. Sometimes it's better to replace a single complex query with more simpler queries because for each result row, columns shared by joins are repeated and delivered to client for processing many times.

Tags: 
programming
SQL
databases
sql-server

Comments

MiltonSOR (not verified)

Tue, 09/07/2019 - 02:10

Hello there! buy viagra pills online great web site

Stepplups (not verified)

Tue, 09/07/2019 - 01:23

Fineviagra cialis Dutasteride Website Cialis Dose Amoxicillin With Other Drugs

Stepplups (not verified)

Tue, 09/07/2019 - 01:16

Fineviagra cialis Dutasteride Website Cialis Dose Amoxicillin With Other Drugs

VirgilStots (not verified)

Tue, 09/07/2019 - 00:14

Howdy! pharmacy technician online program beneficial web site

VirgilStots (not verified)

Tue, 09/07/2019 - 00:11

Howdy! pharmacy technician online program beneficial web site

MiltonSOR (not verified)

Mon, 08/07/2019 - 03:25

Hello! buy viagra medication very good web site

VirgilStots (not verified)

Mon, 08/07/2019 - 03:22

Howdy! pharmacy technician online courses great site

Brettirrix (not verified)

Mon, 08/07/2019 - 03:22

Citalopram

MiltonSOR (not verified)

Mon, 08/07/2019 - 03:19

Hello! buy viagra medication very good web site

VirgilStots (not verified)

Mon, 08/07/2019 - 03:17

Howdy! pharmacy technician online courses great site

VirgilStots (not verified)

Mon, 08/07/2019 - 03:15

Howdy! pharmacy technician online courses great site

MiltonSOR (not verified)

Mon, 08/07/2019 - 03:14

Hello! buy viagra medication very good web site

MiltonSOR (not verified)

Mon, 08/07/2019 - 03:10

Hello! buy viagra medication very good web site

LesKern (not verified)

Sun, 07/07/2019 - 05:06

Para Que Sirve El Viagra Yahoo Price Canada Buy Propecia generic viagra Impotencia Propecia Propecia Treatments Buy Nexium Esomeprazole

LesKern (not verified)

Sun, 07/07/2019 - 04:58

Para Que Sirve El Viagra Yahoo Price Canada Buy Propecia generic viagra Impotencia Propecia Propecia Treatments Buy Nexium Esomeprazole

RebImparf (not verified)

Sun, 07/07/2019 - 02:39

Viagra Generic Dealers In Canada Generique Finasteride viagra Acheter Cialis Pharmacie France Diclofenac Buy Online

RebImparf (not verified)

Sun, 07/07/2019 - 02:36

Viagra Generic Dealers In Canada Generique Finasteride viagra Acheter Cialis Pharmacie France Diclofenac Buy Online

RebImparf (not verified)

Sun, 07/07/2019 - 02:31

Viagra Generic Dealers In Canada Generique Finasteride viagra Acheter Cialis Pharmacie France Diclofenac Buy Online

RebImparf (not verified)

Sun, 07/07/2019 - 02:25

Viagra Generic Dealers In Canada Generique Finasteride viagra Acheter Cialis Pharmacie France Diclofenac Buy Online

Michaelexpor (not verified)

Fri, 05/07/2019 - 13:59

Hello there! best place to order propecia great internet site.

Michaelexpor (not verified)

Fri, 05/07/2019 - 13:56

Hello there! best place to order propecia great internet site.

Michaelexpor (not verified)

Fri, 05/07/2019 - 13:54

Hello there! best place to order propecia great internet site.

Michaelexpor (not verified)

Fri, 05/07/2019 - 13:46

Hello there! best place to order propecia great internet site.

Stewartskist (not verified)

Fri, 05/07/2019 - 10:21

BUY AMOXICILLIN

Stepplups (not verified)

Thu, 04/07/2019 - 21:52

Low Cost Alternatives And Viagra cheap cialis online Viagra Foros Cialis Spedizione 24 Ore

Stepplups (not verified)

Thu, 04/07/2019 - 21:47

Low Cost Alternatives And Viagra cheap cialis online Viagra Foros Cialis Spedizione 24 Ore

Michaelexpor (not verified)

Thu, 04/07/2019 - 20:57

Hi there! cheapest way to buy propecia very good web page.

Michaelexpor (not verified)

Thu, 04/07/2019 - 20:54

Hi there! cheapest way to buy propecia very good web page.

Michaelexpor (not verified)

Thu, 04/07/2019 - 20:48

Hi there! cheapest way to buy propecia very good web page.

Michaelexpor (not verified)

Thu, 04/07/2019 - 20:44

Hi there! cheapest way to buy propecia very good web page.

Michaelexpor (not verified)

Thu, 04/07/2019 - 03:06

Hi! where can i buy propecia in the us very good web site.

Michaelexpor (not verified)

Thu, 04/07/2019 - 03:00

Hi! where can i buy propecia in the us very good web site.

Michaelexpor (not verified)

Thu, 04/07/2019 - 02:55

Hi! where can i buy propecia in the us very good web site.

Michaelexpor (not verified)

Thu, 04/07/2019 - 02:52

Hi! where can i buy propecia in the us very good web site.

Stepplups (not verified)

Wed, 03/07/2019 - 16:39

Cialis Nombre Generico Cod Direct Bentyl Next Day Medicine Mastercard Accepted Buy Kamagra Oral Jelly brand levitra canada Sildenafil Tablets To Buy Cialis 5mg Prix Pharmacie

Stepplups (not verified)

Wed, 03/07/2019 - 16:28

Cialis Nombre Generico Cod Direct Bentyl Next Day Medicine Mastercard Accepted Buy Kamagra Oral Jelly brand levitra canada Sildenafil Tablets To Buy Cialis 5mg Prix Pharmacie

Brettirrix (not verified)

Wed, 03/07/2019 - 11:05

prednisone erythromycin buy wellbutrin lexapro prices where can i buy tetracycline

Josephlam (not verified)

Wed, 03/07/2019 - 02:10

Howdy! buy propecia online without prescription excellent website

Josephlam (not verified)

Wed, 03/07/2019 - 02:02

Howdy! buy propecia online without prescription excellent website

Josephlam (not verified)

Wed, 03/07/2019 - 02:00

Howdy! buy propecia online without prescription excellent website

Josephlam (not verified)

Wed, 03/07/2019 - 01:58

Howdy! buy propecia online without prescription excellent website

Lucasglurb (not verified)

Tue, 02/07/2019 - 16:50

Hello! online indian pharmacy good web site.

Lucasglurb (not verified)

Tue, 02/07/2019 - 16:48

Hello! online indian pharmacy good web site.

Lucasglurb (not verified)

Tue, 02/07/2019 - 16:45

Hello! online indian pharmacy good web site.

Lucasglurb (not verified)

Tue, 02/07/2019 - 16:42

Hello! online indian pharmacy good web site.

Antionesub (not verified)

Tue, 02/07/2019 - 12:41

Hi! remote consultation online pharmacies excellent internet site.

Antionesub (not verified)

Tue, 02/07/2019 - 12:38

Hi! remote consultation online pharmacies excellent internet site.

Antionesub (not verified)

Tue, 02/07/2019 - 12:34

Hi! remote consultation online pharmacies excellent internet site.

Antionesub (not verified)

Tue, 02/07/2019 - 12:32

Hi! remote consultation online pharmacies excellent internet site.

Antionesub (not verified)

Mon, 01/07/2019 - 15:29

Hi! generic viagra online canada pharmacy good site.

Pages