Microsoft's SQL Server is a relational database management system (RDBMS) that runs as a server providing multi-user access to a number of databases. It originated from the Sybase SQL Server codebase, which is why both products use the extension of SQL called Transact-SQL (T-SQL).

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routine to backup ssas databases fails with: The XML for Analysis request timed out before it was completed

I have developed my own stored procedure, that through a LINKED SERVER, backups the SSAS databases according to a table value parameter. the code for the stored procedure is below. the problem: it ...
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How to select top 10 records from each category

I have a table with fields Hour, PathId, Duration, Event, CellId, Channel I have 50+ CellId. Each CellId has four PathId (i.e. 0, 1, 2, 3). Each PathId has many Events and Durations. Now I want to ...
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What's the difference between a CTE and a Temp Table?

What is the difference between a Common Table Expression (CTE) and a temp table? And when should I use one over the other? CTE WITH cte (Column1, Column2, Column3) AS ( SELECT Column1, Column2, ...
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Which database could handle storage of billions/trillions of records?

We are looking at developing a tool to capture and analyze netflow data, of which we gather tremendous amounts of. Each day we capture about ~1.4 billion flow records which would look like this in ...
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As a DBA, how would I go about transitioning from Oracle to SQL Server?

I'm an Oracle DBA that also has Sybase experience. What are the major architectural and conceptual differences between the two RDBMS platforms? An answer similar to the SQl Server->Oracle question ...
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How to make a transition from SQL Server DBA to Oracle?

As an interest, if I would to transition from a SQL Server DBA to Oracle what will be the major learning or unlearning that I would have to do? I would assume the concepts are the same and the ...
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Handling growing number of Tenants in Multi-tenant Database Architecture

Handling a modest number of customers (tenants) in a common server with separate databases for each tenant's instance of the application is relatively straightforward and is normally the correct way ...
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What is the difference between a “record” and a “row” in SQL Server?

There was a rather innocuous question about adding dates and times in SQL Server that set off a rather fascinating taxonomic debate. So how do we differentiate between these related terms and how we ...
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Identifying Unused Stored Procedures

This next year, I am helping an effort to clean several SQL Server environments. We have about 10,000 stored procedures and estimate that only about 1000 of them are used on a regular basis, and ...
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High Disk I/O from sql server or is High disk I/O slowing sql server?

I've been arguing with a DBA and a couple hardware guys about performance issues on our SQL server. Normally everything is fine, however over the past few weeks we have been having huge lag spikes in ...
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Optimising plans with XML readers

Executing the query from here to pull the deadlock events out of the default extended events session SELECT CAST ( REPLACE ( REPLACE ( XEventData.XEvent.value ...
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Can I install SQL Server Management Studio locally?

Can I install SQL Server Management Studio on my desktop to access a database on a SQL Server 2012 instance? If so, where can I find the installer? Google searches only return 'express' versions ...
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Sql Server - Best Practices for Growing Database Files

I have been monitoring file growth via the data collector in sql server 2008 r2 for two weeks. The database is growing consistently at around 35(MB)/Day. The DB has not yet hit the initial size of 2 ...
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SIMPLE or FULL recovery model for databases?

When should I use the full recovery model and when should I use the simple recovery model for databases? I always used the full recovery model because it is the default, but today i encountered this ...
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What is a Clustered Index?

I need a short explaining of clustered index. What is a clustered index? What are best practices for using the clustered index?
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Does the order of columns in a table's definition matter?

When defining a table, it's helpful to order the columns in logical groups and the groups themselves by purpose. The logical ordering of columns in a table conveys meaning to the developer and is an ...
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Is there any benefit to defragmenting SQL indexes in a SAN environment?

Our SQL server lives on a SAN. It contains dozens of OLTP databases, some with several tables containing over 1m records. We have been running Ola Hallengren's index maintenance scripts weekly, and ...
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Cannot start SqlLocalDB instance with my Windows account

I'm the administrator and simply run the command: sqllocaldb start v11.0 Result: Start of LocalDB instance "v11.0" failed because of the following error: Error occurred during LocalDB instance ...
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Adding columns to production tables

What's the best way to add columns to large production tables on SQL Server 2008 R2? According to Microsoft's books online: The changes specified in ALTER TABLE are implemented immediately. If the ...
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Find out what queries are causing the biggest amount of network traffic

On a production SQL server I am seeing intermittent enormous spikes in data traffic. Up to 200Mbit/s which is causing NETWORK IO waits which in turn cause query timeouts. How can I find out what ...
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What is blocking and how does it happen?

I tried to find some information about blocking in SQL Server, but I could not find a concise explanation for what it is and how it happens. Could you please enlighten me?
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What's the easiest way to create a temp table in SQL Server that can hold the result of a stored procedure?

Many times I need to write something like the following when dealing with SQL Server. create table #table_name ( column1 int, column2 varchar(200) ... ) insert into #table_name execute ...
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PostgreSQL Initial Database Size

There are 2 parts to my question. Is there a way of specifying the initial size of a database in PostgreSQL? If there isn't, how do you deal with fragmentation when the database grows over time? ...
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.bak file not visible in any directory in SSMS

I have a .bak file created today by someone else, manually created through SSMS 2008 R2. I'm trying to manually restore the database, unfortunately the file isn't appearing when I go to browse it. I ...
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How and when does SQL Agent update next_run_date/next_run_time values?

I've been working on code in T-SQL to add new schedules to a SQL Agent job using the sp_add_jobschedule proc in the msdb database. When I add a new schedule (typically a run-once at a specific ...
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ETL: extracting from 200 tables - SSIS data flow or custom T-SQL?

Based on my analysis, a complete dimensional model for our data warehouse will require extraction from over 200 source tables. Some of these tables will be extracted as part of an incremental load and ...
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Setting user permissions for different SQL Server schemas

I need to limit access to a particular user, but they still need to be able to see the data in tables owned by dbo. I'm trying to do the following: dbo schema functions as it would normally, has ...
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SQL query to return a column per date in date range?

Let me explain what I've got and what I'm trying to achieve. Let's say I have Table A: BookingsPerPerson Person_Id ArrivalDate DepartureDate 123456 2012-01-01 2012-01-04 213415 ...
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SQL Server - what isolation level for non-blocking select statements?

I have a long running transaction (called, say, T1) that performs some deletes, updates and inserts on a table in SQL Server 2008 R2. At the same time, another process periodically runs select ...
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Why is a .bak so much smaller than the database it's a backup of?

I just took a backup of a SQL Server database. The MDF and LDF files together total around 29 GB, but the .bak file was only 23 GB, about 20% smaller. My first guess when one version of a set of ...
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3answers
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Is there a way to generate table create script in TSQL?

Is there a way to generate a create script from an existing table purely in T-SQL (that is without using SMO, since T-SQL does not have access to SMO). Let's say a stored procedure that receives a ...
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Setting up a central CLR stored procedure / function respository library for internal stored procs in other databases to use?

I would like to use code that I developed in C# CLR to be used in all of the databases on the system so that I don't have to set each to trustworthy and turn CLR on and keep a bunch of the same code ...
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Common Table Expression (CTE) benefits?

From msdn : Unlike a derived table, a CTE can be self-referencing and can be referenced multiple times in the same query. I'm using CTEs quite a lot, but I've never thought deeply about the ...
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Need to understand parallel query execution error

Today we experienced a degradation in performance on our production sql server. Durring the time this occurred we logged several "The query processor could not start the necessary thread resources ...
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1answer
820 views

Is there a reliable way to determine when you should run DBCC CLEANTABLE to reclaim space?

Lately, instead of just growing files when they near 80% file utilization, I've been more proactive at reclaiming space via the usual tricks like defragmenting heaps, adding & dropping clustered ...
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3answers
610 views

Would it be considered as a bad practice to have multiple nullable FKs on a table in SQL Server

On my database structure in SQL Server, I have 3 types of products which requires different information about the order. So, I created one Customers table and three different orders tables: ...
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Listing the existing SQL Server Logins and Users

I know we can check the logins and the users that are defined, using GUI in SQL Server, but am wondering how we can do this check using script. I ran the query below but it shows Principal_id which ...
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4answers
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SQL Server script to delete accounts no longer in Active Directory

We have a SQL Server 2000 that will shortly be migrated to SQL Server 2005. It has years of Windows Authentication accounts created that no longer exist in Active Directory, which prevent the Copy ...
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'Conversion failed' error with ORDER BY CASE expression

I have the following Stored Procedure that works great EXCEPT when I set the 'OrderBy' to 'OrderNumber'. I get the following error: Conversion failed when converting the nvarchar value 'SK11270' to ...
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Guarantee SQL Server Identity Columns that two consecutive values differ by constant increments?

I posed a question about Denali sequences here and another question about emulation of identity columns in Oracle Global Tables here. I always thought that I could trust that identity values ...
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How to move data from big table

There is a big table (5-6 million records). I have to move 90% of old records to other database(table). Solution?
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SQL Server 2008 R2 High memory usage

I have SQL Server 2008 R2 that runs multiple jobs over night, the problem is SQL Server will eat up all RAM and CPU, then it will not release the RAM resources after the job finishes, as a workaround ...
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1answer
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Query optimizer recommends adding index instead of using existing index

I am trying to determine why the query optimizer in SQL Server is recommending creating a new index instead of using an existing index that appears to be sufficient for the query. First the table. ...
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When to make changes to the cost threshold for parallelism

While examining a performance issue , I have seen an influx on CXPACKETS suggesting I might need to look at the cost threshold for parallelism and perhaps the MAXDOP. Before making any drastic ...
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How to backup/restore SQL Server database from command line similar to mysql

I need to automate the migration for some databases from an older server. I know that script a tool using C# for example can be a possibility but I need a simple, fast and effective solution in order ...
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2answers
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How can I find databases with a large number of virtual log files?

I have several databases on a production server that are in the hundreds of gigabytes, and have many thousands of transactions running through them on a daily basis. Almost all these databases are ...
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Running queries with SQLCMD vs. Running queries with SSMS

I've noticed something which i'm not sure about. can it be that running queries directly with SSMS is much faster than running queries with SQLCMD? I've noticed that the results of queries that ran ...
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NULLs in a composite primary key - SQL Server

I'm trying to work out the best way of creating SQL Server primary keys, foreign keys and constraints to accurately represent my data model in LINQ / Entity Data Objects. Let's assume - for the ...
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Not able to create SSISDB catalog

Getting the error below while trying to create a catalog in sql server 2014 integration services. Any idea what I missed in installation or anywhere else? The catalog backup file 'C:\Program ...
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3answers
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Copy a large data from sql query result

In my sql server 2008, after running the query the data return is very huge say in millions. I tried copying but it gives an exception sql memory error. Can you let us know how can i copy the entire ...