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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38
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20k views

Why does ALTER COLUMN to NOT NULL cause massive log file growth?

I have a table with 64m rows taking 4.3 GB on disk for its data. Each row is about 30 bytes of integer columns, plus a variable NVARCHAR(255) column for text. I added a a NULLABLE column with ...
8
votes
2answers
8k views

For absolute performance, is SUM faster or COUNT?

This relates to counting the number of records that match a certain condition, e.g. invoice amount > $100. I tend to prefer COUNT(CASE WHEN invoice_amount > 100 THEN 1 END) However, this is ...
5
votes
1answer
5k views

SQL Server - How to determine ideal memory for instance?

We have some virtual machines that have X memory allocated to them. This amount of memory is somewhat random. It was allocated to the machine because that was the amount of memory the physical ...
5
votes
1answer
2k views

Find transactions that are filling up the version store

we have enabled the "READ_COMMITTED_SNAPSHOT" for some of our SQL Server 2005 databases. Now from time to time we see that our TempDB is filling up the harddisk and we suspect the version store to be ...
3
votes
2answers
840 views

Run a PowerShell script on a different server - from inside a SQL Server job

I have a procedure to backup SSAS Databases. That is working as a charm. Now my server is filling up with SSAS backups and I would like to delete the backup files that are older than 2 days. to ...
11
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3answers
4k views

Is it possible to backup and restore part of a database in sql-server?

We have a sql-server 2005 database that we regularly transfer from our client site to ours. This takes a long time because we don't have a direct connection and have to transfer the file over their ...
5
votes
1answer
3k views

Kerberos authentication not working with Linked Servers in SQL Server 2012

I am setting up a DEV/TEST environment using 2 SQL Servers running SQL Server 2012 on Windows Server 2012. We are moving from SQL Server 2005 on Windows Server 2008, where we already have this ...
71
votes
4answers
14k views

Why use both TRUNCATE and DROP?

In the system I work on there are a lot of stored procedures and SQL scripts that make use of temporary tables. After using these tables it's good practice to drop them. Many of my colleagues (almost ...
52
votes
5answers
20k views

When to use TINYINT over INT?

In general, I always use Ints. I know that in theory this is not the best practice, though, since you should use the smallest data type that will be guaranteed to store the data. For example, it's ...
46
votes
4answers
24k views

Why would SET ARITHABORT ON dramatically speed up a query?

The query is a single select containing a lot of grouping levels and aggragate operations. With SET ARITHABORT ON is takes less than a second, otherwise it takes several minutes. We have seen this ...
24
votes
4answers
23k views

When is it OK to shrink a Database?

I know shrink is the devil: It reverses page order and is responsible for skin cancer, data fragmentation, and global warming. The list goes on... That being said, say I have a 100 GB database and I ...
21
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4answers
84k views

Restore SQL Server 2012 backup to a SQL Server 2008 database?

Is there a way to restore a SQL Server 2012 database backup to a SQL Server 2008? I tried to attach file, it does not work.
17
votes
2answers
6k views

Stored procedures vs. inline SQL

I know stored procedures are more efficient through the execution path (than the inline sql in applications). However, when pressed, I'm not super knowlegeable about why. I'd like to know the ...
17
votes
2answers
28k views

How to find the SQL statements that caused tempdb growth?

The tempdb of a server (SQL Server 2008) increases to 500GB+ several times every month. Is it possible to find out which SQL statements caused this problem? The problem is usually not caused by create ...
13
votes
3answers
6k views

SQL Server Agent Jobs and Availability Groups

I'm looking for best practice in dealing with scheduled SQL Server Agent jobs in SQL Server 2012 availability groups. Maybe I missed something, however at the current state I feel that SQL Server ...
13
votes
3answers
12k views

What can cause a mirroring session to timeout then failover? SQL Server 2005

We have two production SQL Servers running SQL Server 2005 SP4 with cumulative update 3. Both servers run on physical machines that are identical. DELL PowerEdge R815 with 4 x 12 core CPUs and 512GB ...
9
votes
3answers
532 views

What is a deterministic method for evaluating a sensible buffer pool size?

I'm trying to come up with a sane way to understand if the max server memory (mb) setting is appropriate (either should be lower, or higher, or stay the way it is). I am aware that max server memory ...
7
votes
5answers
976 views

Over use/correct use of schemas?

Having asked This question on Stackoverflow, I wondered where what I have done is correct/best practise. Basically, every object that I create is going into a schema with the schema name reflecting a ...
15
votes
2answers
4k views

How (and why) does TOP impact an execution plan?

For a moderately complex query I am trying to optimize, I noticed that removing the TOP n clause changes the execution plan. I would have guessed that when a query includes TOP n the database engine ...
14
votes
4answers
40k views

How to add sysadmin to user in SQL Server 2008 when no sysadmin accounts exist

I have a SQL server 2008 instance running. Unfortunately during testing I deselected the sysadmin rights for my login and now can't readd it (because I don't have sysadmin rights). There are no other ...
12
votes
4answers
19k views

Methods of speeding up a huge DELETE FROM <table> with no clauses

Using SQL Server 2005. I am performing a huge DELETE FROM with no where clauses. It's basically equivalent to a TRUNCATE TABLE statement - except I'm not allowed to use TRUNCATE. The problem is ...
10
votes
4answers
4k views

Help me choose a RAID level combination for a SQL Server 2008 instance

I am going to rebuild one IBM 3400 server from scratch. This server is dedicated to a SQL Server 2008 instance running on Windows 2008 R2. I am going to make new RAID configuration. I have 6 SCSI ...
3
votes
1answer
7k views

No SA password. No SQL Server Management Studio. No OS authentication [duplicate]

I have this problem. I need to do some administrative tasks on a MS SQL Database using SA account. OS authentication is not set. SQL Server Manager Manager Studio is not installed. I have no other ...
8
votes
3answers
26k views

Copy complete structure of a table

Using some methods, when you create a copy of a table you lose indexes, PK, FK, etc. For example in SQL Server I can say: select * into dbo.table2 from dbo.table1; This is just a simple copy of the ...
7
votes
1answer
19k views

Login failed for user - Error 18456 - Severity 14, State 38

Message that SQL Server Log File Viewer shows: Login failed for user [User] Error: 18456, Severity: 14, State 38 What it actually means: Failed to open the explicitly specified database My ...
6
votes
1answer
622 views

The use of NOT logic in relation to indexes

According to Microsoft's book on database development Exam 70-433: Microsoft SQL Server 2008 Database Development: Neither leading wildcard characters not NOT logic allow the query optimizer to ...
3
votes
1answer
380 views

VLDB with large quantity of data file imports

I am a little out of my league with this scenario and hope this community can help get me on the right direction. I have recently been tasked with re-designing and implementing a database application ...
3
votes
4answers
37k views

List all permissions for a given role?

I've searched around all over and haven't found a conclusive answer to this question. I need a script that can give ALL permissions for an associated role. Any thoughts, or is it even possible? ...
8
votes
1answer
4k views

SQL Server 2012: Generate Scripts from command line

I am running SQL Server 2012. The SQL Server Management Studio has the option to right click on a database then select Tasks and Generate Scripts. Is there a way to automate that via command line ...
7
votes
2answers
12k views

Quick look at how much RAM is allocated to SQL Server?

With SQL Server 2005, you could look at the Task Manager and, at least, get a cursory look at how much memory is allocated to SQL Server. With SQL Server 2008, the Working Set or Commit Size never ...
5
votes
5answers
6k views

SQL Server 2012 AlwaysOn: need to automatically add databases by script- T-sql or PowerShell

I've installed and successfully configured our SQL Server 2012 AlwaysOn 2-node servers for our new "Intranet" that is coming out. I've gotten AlwaysOn working great, and our Front End servers for the ...
3
votes
1answer
2k 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 ...
17
votes
3answers
3k views

Justify NOT using (nolock) hint in every query

Have you ever had to justify NOT using a query hint? I am seeing WITH (NOLOCK) in every single query that hits a very busy server. It is to the point that the developers think it should just be on ...
10
votes
2answers
623 views

Setting READ UNCOMMITTED when reading DMVs

I've seen several people call SET TRANSACTION ISOLATION LEVEL READ UNCOMMITTED before reading system DMVs. Is there ever any reason to do this, assuming you aren't mixing calls to DMVs and tables in ...
8
votes
1answer
3k views

Trouble With Database Permissions for sp_send_mail

I am trying to send database mail but I am getting EXECUTE permission denied on the object 'sp_send_dbmail' database 'msdb', schema 'dbo'.. I code I am running is as follows: SELECT SUSER_NAME(), ...
7
votes
3answers
17k views

Reset IDENTITY value

I have a table with an IDENTITY column. While developing I delete the rows from time to time and add them again. But the IDENTITY values always kept increasing and didn't start from 1 when I added ...
7
votes
2answers
12k views

SQL Server gets slow over time until we have to restart it

We have a database with a mixed OLAP/OLTP workload. The queries are quite ad-hoc and are dynamically created in the mid-tier application server. When we start the server, the performance is quite ...
5
votes
1answer
3k views

SQL Server: hierarchy of permissions for schema?

We have several databases under development and I would like to start using SQL Server schemas for permission management and logical grouping of database objects. Under Schema Properties there is ...
4
votes
5answers
28k views

Why is SQL Server consuming more server memory?

Sqlserver is consuming 87.5 % of my server Ram. This recently causes alot of performance bottleneck such as slowness.I Research on this issue. One common solution i could find on the internet is to ...
3
votes
1answer
449 views

Limiting database security

A number of texts signify that the most important aspects offered by a DBMS are availability, integrity and secrecy. As part of a homework assignment I have been tasked with mentioning attacks which ...
13
votes
2answers
6k views

How to know when/if I have too many indexes?

Running Microsoft SQL Server Profiler every now and then, it suggests me with a bunch of new indexes and statistics to create ("...97% estimated improvement..."). From my understanding every added ...
8
votes
1answer
336 views

Are the cost percentages in this SQL Server plan over 100% for a valid reason?

I'm looking through the plan cache, looking for low-hanging optimization fruit and came across this snippet: Why are many of the costs listed above 100% ? Shouldn't that be impossible?
5
votes
2answers
5k views

Find which session is holding which temporary table

We have a SQL Server 2005 database the temp database has become full. By going into SQL Server Management Studio I can see all the temporary tables in the tempdb. Is it possible to tell which session ...
5
votes
2answers
4k views

Issues with TempDB mdf file ever increasing

I have a tempdb growth issue. Let me preface everything by giving my tempdb settings. Even with no queries running on the database/server tempdb keeps on increasing in size, at first rapidly and ...
5
votes
1answer
2k views

Storage order vs Result order

This is a spin-off question from Sort order specified in primary key, yet sorting is executed on SELECT. @Catcall says this on the subject of storage order (clustered index) and the output order ...
4
votes
5answers
16k views

Convert varchar column to datetime

In SQL Server, I have a varchar column with value such as: 07/May/2012:00:06:22 07/May/2012:00:06:22 07/May/2012:00:06:22 07/May/2012:00:06:22 07/May/2012:00:06:22 QUESTIONS How do I convert ...
2
votes
2answers
78 views

Unexpected gaps in IDENTITY column

I'm trying to generate unique purchase order numbers that start at 1 and increment by 1. I have a PONumber table created using this script: CREATE TABLE [dbo].[PONumbers] ( [PONumberPK] [int] ...
2
votes
3answers
668 views

Copy database to local from server [duplicate]

As I show , I have server database version-10.50.1600 and local database version-10.0.1600 . How can I copy database (with all tables and data(s)) from server to local which has different version ? ...
2
votes
1answer
1k views

Conversion of varchar data to datetime failing

We are in the process of moving data from a legacy table (all varchar fields) into a strongly typed counterpart cue cheering As part of this effort, we are taking data from the base Entity table and ...
1
vote
1answer
1k views

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 ...