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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Why does a UNIQUE constraint allow only one NULL?

Technically, NULL = NULL is False, by that logic no NULL is equal to any NULL and all NULLs are distinct. Shouldnt this imply that all NULLs are unique and a unique index should allow any number of ...
13
votes
2answers
6k views

Difference between SQL batch, statement and RPC?

What is the difference between SQL batch, T-SQL statement and Remote Procedure Call? How can I tell if part of the T-SQL code is a batch or statement?
11
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2answers
3k views

SQL Server VARCHAR Column Width

Searching around the web, I have found conflicting advice on whether there is a performance impact when specifying overly-wide VARCHAR columns, e.g. VARCHAR(255) when VARCHAR(30) will probably do. I ...
10
votes
1answer
883 views

SQL Server 2012 Page Life Expectancy resets to 0 after about 50 days

I've noticed an odd behavior on a 2-server HA cluster and I was hoping someone could confirm my suspicion, or maybe offer some other explanation... Here is my setup: A 2-server SQL 2012 SP1 ...
10
votes
3answers
647 views

Optimizing a CTE hierarchy

Update below I have a table of accounts with a typical acct/parent account architecture to represent a hierarchy of accounts (SQL Server 2012). I created a VIEW using a CTE to hash out the hierarchy, ...
9
votes
4answers
3k views

When was Torn Page Detection and Checksum introduced to SQL Server and what are the upgrade behaviors?

There are two different options in modern SQL Server for page verify; being Torn Page Detection and Checksum. None is also of course an option. I believe Checksum was introduced in SQL Server 2005 ...
9
votes
2answers
726 views

Hard limitation for merge replication article count?

A bit of background. We developed an app that uses merge replication. Right now, we are currently publishing about 212 articles, and everything is fine, as it appears to fall into the 256 article ...
9
votes
1answer
759 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 ...
8
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3answers
1k views

INSERT takes over 5 hours, when inserting more than specific number of rows

When inserting less then about 1,350,000 rows to the table it all takes about 2 minutes, however when number of inserted rows is bigger, then the time needed to insert data grows to about 5 hours. ...
8
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1answer
453 views

In case of multiple updates of the same record in a single transaction, how many versions are being stored?

According to MSDN article by Kimberly L. Tripp, Neal Graves's "SQL Server 2005 Row Versioning-Based Transaction Isolation "... All the earlier versions of a particular record are chained in a linked ...
8
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2answers
882 views

What is the meaning of DOP in the context of SQL Server?

What is the meaning of DOP in the context of sql server?
7
votes
3answers
551 views

Restricting users to COPY ONLY backups

I am looking to deploy log shipping in my production environment. This will mean I will have to manage backup chains which could be disrupted by people taking backups to refresh development ...
7
votes
4answers
9k views

Converting RTF in a text column to plain text in bulk

I have a legacy system with about 10 million rows in a table. In that table there is a column of type text, most of them are standard text but about 500 thousand rows have RTF markup in them. I need ...
7
votes
2answers
765 views

Can Availability Groups replace transactional replication?

I've been looking at the new features of SQL Server 2012, and how it can help my current situation. Currently we're on SQL Server 2008 R2, and replicate two OLTP servers' databases to a single ...
7
votes
2answers
625 views

Code creates different plan when ran ad-hoc vs. in a stored procedure

I have a delete statement that is using a bad plan when run inside a stored procedure, but is choosing a much better plan when run ad-hoc. I have rebuilt all the indexes for the tables used by the ...
7
votes
4answers
1k views

SQL Server: what should be done when a process is blocking another process?

I'm an accidental DBA and still learning. When I see from DMV:s or Activity Monitor that some process is blocking another process, what should be done? Should I simply kill those processes or is ...
6
votes
2answers
593 views

Is there a limit to how many credentials SSMS can remember?

Using SQL Server Management Studio that came with SQL Server 2008 R2, I make connections to the same server using a number of different sets of SQL Server Authentication credentials. On my development ...
6
votes
2answers
3k views

Transaction Log maintenance on Mirror database

SQL Server Version: 2008 R2 Enterprise SP2 I am trying to get a handle on our SQL Server maintenance and I came across something I think is incorrect. We have a single production instance with 3 ...
6
votes
3answers
15k views

Pivot rows into multiple columns

I have a SQL Server instance that has a linked server to an Oracle server. There is a table on the Oracle server called PersonOptions which contains the following data: ╔══════════╦══════════╗ ║ ...
6
votes
1answer
255 views

How to Optimise Query

I have a database structure similar to this, CREATE TABLE [dbo].[Dispatch]( [DispatchId] [int] NOT NULL, [ContractId] [int] NOT NULL, [DispatchDescription] [nvarchar](50) NOT NULL, ...
6
votes
4answers
4k views

Passing in the table into a stored procedure

Is it possible to pass in the name of a table into a stored procedure? For example, suppose you have several views of the same table. They all have the exact same structure. You want a store ...
6
votes
2answers
279 views

Automation of backups of Large Number of Database

In a multi-tenant web application where a database is set up for each tenant, the database can be backed up and restored manually through a fairly conventional approach. I am considering this type of ...
6
votes
2answers
4k views

Recover accidentally deleted rows from a table

My client has accidentally deleted all the records of a table from a test database. This test database is in SQL Server 2005 Express and we don't have a backup. Is it possible to restore the deleted ...
6
votes
1answer
750 views

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 ...
4
votes
1answer
416 views

What is the correct way to ensure unique entries in a temporal database design?

I'm having trouble with the design of a temporal database. I need to know how to make sure I have only one active record for any given timeframe for a store. I have read this answer, but I'm afraid I ...
4
votes
6answers
8k views

SQL Server log shrinking Issue [duplicate]

Possible Duplicate: Why Does the Transaction Log Keep Growing or Run Out of Space? I have a 300 GB database log in our SQL Server. I want to shrink all the logs but it is not allowing me to ...
4
votes
3answers
4k views

Test if any fields are NULL

I'm trying to figure out an easy query I can do to test if a large table has a list of entries that has at least ONE blank (NULL / empty) value in ANY column. I need something like SELECT * FROM ...
4
votes
1answer
1k views

SQL Server: How to create a table that fills one 8 KB page?

Is there a way to calculate the amount of data that fills one 8 KB page in SQL Server and create a table that fills one page entirely? This kind of table is presented in in this blog post.
3
votes
2answers
1k views

Should I pause Mirroring and stop SQL Server services before running windows updates?

I am running Windows update on my SQL Servers (which are in a Principal-Mirror partnership, in High Safety mode). I am starting with updating the mirror and I was wondering, to increase safety, ...
3
votes
2answers
929 views

Missing Transaction log in chain, Possible to skip

We have had one of our clients SQL Servers crash and need to restore it to the most recent possible time. We have a full backup from Monday and transaction logs that run every hour up until this ...
3
votes
1answer
19k views

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 ...
3
votes
1answer
4k views

Transaction Log Maintanance While Using AlwaysOn Availability Group

We are using HADR ( AlwaysOn Availability Group) feature of SQL Server 2012. Server and AG Configuration as below: SQL12_SRV1 --> AG1(PRIMARY) - SYNC -->> DBTest SQL12_SRV2 --> AG1(SECONDARY) ...
3
votes
1answer
1k views

SQL Server Many-to-One replication

I have 8 individual SQL Server 2008 R2 machines, each hosting 1 database. Each database has an identical table structure and schema, and entirely unique data. I would like to establish a reporting ...
3
votes
2answers
565 views

Server permissions of an activation stored procedure of a Server Broker queue

I have a stored procedure that queries the sys.dm_exec_requests view. In the stored procedure the view only returns one row, while the stored procedure needs to see all of them. The MSDN article on ...
3
votes
2answers
1k views

SQL Server media belongs to which edition

Could anyone please help me on below question? Without installing SQL Server media 2008 and 2012, how can we know that the media belongs to which edition (like developer, standard or ...
3
votes
0answers
130 views

How to Audit for Access with Cross Database Ownership Chaining

I've just joined the data team of a new company and we have a large SQL Server environment (100+ instances) and cross database ownership chaining is on by what I gather is a necessity. I'm looking for ...
3
votes
1answer
8k views

Restore Backup Fails - File 'Db' cannot be restored to '{…}.mdf'. Use WITH MOVE to identify a valid location for the file

I am getting the following errors trying to do a restore using the restore command on a backup file I recieved from a customer. RESTORE DATABASE SFDB FROM DISK = N'C:\Backup\Backup.bak' Any ...
3
votes
1answer
135 views

Analysing A Query Plan

Why is the following query slow? select count(*) from [dbo].[mt_dispatch_link] , [dbo].[_mt_dispatch] [_mt_dispatch] where (mt_dispatch_link.contract_id_1 = _mt_dispatch.contract_id ...
3
votes
3answers
2k views

View foreign key constraints so I can delete a table

I have copied a database I was working on so I could change some key elements of its design for my new version. I want to delete totally some tables from the database however I cannot due to some ...
3
votes
2answers
3k views

Problem Reaching VM SQL Server Instance

Here's what I'm working with right now. I have a host OS which includes a SQL Server 2008 Enterprise instance. I have a virtual machine running on this host which has a SQL Server 2008 R2 Express ...
3
votes
2answers
9k views

SQL query that concatenate values from duplicate rows in a single table

Lets say I have a table of employees, like this: Name Sex Role Bob M Developer Joe M QA Now, I have a problem with this table of duplicated rows. I will fix it ...
2
votes
1answer
127 views

Why is my filtered index being ignored?

--Setup, actual queries after the space --create table fltrind (a integer,b integer) truncate table fltrind DROP INDEX fltrind.nf DROP INDEX fltrind.f DECLARE @i integer SET @i=0 while @i<100 BEGIN ...
2
votes
2answers
15k views

How do I find a long running query with process ID, process name , login time, user , start time and duration?

Can anyone help me to find a below given details for long running query. ProcessID, process name, database, host ,user ,process login time, query start time and query duration. I am looking for a ...
2
votes
1answer
4k views

Migrating from SQL Server 2005 to SQL Server 2008 R2 on a different box

We currently have a SQL Server 2005 instance hosting a lot of application specific databases (ArchiveManager, SolarWinds, Kaspersky etc). We are planning to deploy a new SQL Server 2008 R2 instance on ...
2
votes
2answers
1k views

Move (Restore) SQL Server 2005 database which does not exist before

I did not ready about this but found out after trying to restore a database from remote server and it wont restore if the database did not exist before. What I would do is create a .bak file ...
2
votes
1answer
30k views

How to determine used/free space within SQL database files?

I normally use the following method to determine the free/used space within each file of a database: Select *, fileproperty(name, 'SpaceUsed') as Used From dbo.sysfiles This returns total and used ...
1
vote
3answers
233 views

Undo SQL UPDATE Azure DB

I have accidentally updated over 3,000 records in one of my tables hosted on Azure. This was not a transaction and I did not have any back ups for this table. I've read around and found ApexSQL Log ...
1
vote
2answers
262 views

SQL 2008 Server - performance loss possibly connected with a very large table

Migrated from http://serverfault.com/questions/615129/sql-2008-server-performance-loss-possibly-connected-with-a-very-large-table We have SQL Server 2008 with 3 active databases running on it. DB1 ...
1
vote
3answers
398 views

Improve performance by partitioning

I'm using SQL Server 2012. I’m using CTE to create an orders table from the items table. The final count for the orders table is around 120 million. It is taking about 2 hours for the whole process. ...
1
vote
1answer
4k views

Set permissions on all objects for SQL users

I have a procedure that loops through all objects in the database and assigns them proper permissions to that object. I want to know if there is a better way to do this? I use a model database to ...