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.

Comments

pharmacy online usa legal online pharmacy provigil online pharmacy

pharmacy online usa legal online pharmacy provigil online pharmacy

buy propecia online buy finasteride online buy propecia no rx

buy propecia online buy finasteride online buy propecia no rx

buy propecia online buy finasteride online buy propecia no rx

buy propecia online buy finasteride online buy propecia no rx

http://imitrex-sumatriptan.com/ - buy imitrex cheap buy imitrex pills buy generic imitrex

http://imitrex-sumatriptan.com/ - buy imitrex cheap buy imitrex pills buy generic imitrex

http://imitrex-sumatriptan.com/ - buy imitrex cheap buy imitrex pills buy generic imitrex

http://imitrex-sumatriptan.com/ - buy imitrex cheap buy imitrex pills buy generic imitrex

where buy propecia order propecia buy propecia no rx

where buy propecia order propecia buy propecia no rx

where buy propecia order propecia buy propecia no rx

where buy propecia order propecia buy propecia no rx

http://imitrex-sumatriptan.com/ - order imitrex buy imitrex pills buy imitrex online without prescription

http://imitrex-sumatriptan.com/ - order imitrex buy imitrex pills buy imitrex online without prescription

http://imitrex-sumatriptan.com/ - order imitrex buy imitrex pills buy imitrex online without prescription

http://imitrex-sumatriptan.com/ - order imitrex buy imitrex pills buy imitrex online without prescription

buy propecia medication purchase propecia online no prescription buy propecia

buy propecia medication purchase propecia online no prescription buy propecia

buy propecia medication purchase propecia online no prescription buy propecia

http://imitrex-sumatriptan.com/ - buy imitrex online buy imitrex cheap buy imitrex with no prescription

http://imitrex-sumatriptan.com/ - buy imitrex online buy imitrex cheap buy imitrex with no prescription

http://imitrex-sumatriptan.com/ - buy imitrex online buy imitrex cheap buy imitrex with no prescription

http://imitrex-sumatriptan.com/ - buy imitrex online buy imitrex cheap buy imitrex with no prescription

purchase propecia online no prescription buy propecia online without prescription order finasteride

purchase propecia online no prescription buy propecia online without prescription order finasteride

purchase propecia online no prescription buy propecia online without prescription order finasteride

purchase propecia online no prescription buy propecia online without prescription order finasteride

http://imitrex-sumatriptan.com/ - where buy imitrex purchase imitrex purchase imitrex

http://imitrex-sumatriptan.com/ - where buy imitrex purchase imitrex purchase imitrex

http://imitrex-sumatriptan.com/ - where buy imitrex purchase imitrex purchase imitrex

http://imitrex-sumatriptan.com/ - where buy imitrex purchase imitrex purchase imitrex

where buy propecia buy finasteride online order propecia

where buy propecia buy finasteride online order propecia

where buy propecia buy finasteride online order propecia

where buy propecia buy finasteride online order propecia

Pages