Questions tagged [sql-server]

All versions of Microsoft SQL Server (not MySQL). Please also add a version-specific tag, like sql-server-2016, since it is often relevant to the question.

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236
votes
18answers
113k views

How do you document your databases?

I find that most of my clients are not documenting their databases at all and I find that pretty scary. To introduce some better practice, I would like to know what tools/process people are using. ...
38
votes
4answers
140k views

How do I list or search all the column names in my database?

I want to search for a string in the names of the columns present in a database. I’m working on a maintenance project and some of the databases I deal with have more than 150 tables, so I'm looking ...
30
votes
4answers
51k views

How can I tell WHY an insert on a certain table is slow?

I know that an INSERT on a SQL table can be slow for any number of reasons: Existence of INSERT TRIGGERs on the table Lots of enforced constraints that have to be checked (usually foreign keys) Page ...
10
votes
6answers
3k views

What security threats does the SA account and other known account names pose to security?

Does an known account name like sa, pose a security threat to database? When using windows authentication on SQL Server does it impose the same password policy(if it was set to say account lockout ...
0
votes
3answers
383 views

Is Oracle not suited as the database behind websites like Stackoverflow? [closed]

I see from the thread Which tools and technologies build the Stack Exchange Network? that the database specifications are: Database SQL Server 2008 R2 running Microsoft Windows Server 2008 ...
11
votes
2answers
216 views

Is there anybody using the SQL Server feature to create groups of stored procedures differentiated by number?

The question refers to the number parameter in this msdn documentation If you don't you can create multiple stored procedures in SQL-Server differentiated by number and drop them with a single drop. ...
10
votes
2answers
4k 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?
12
votes
1answer
3k views

What is the impact of changing the index creation memory setting in SQL Server?

I am trying to create some indexes a SQL Server 2008 database but am getting the following error message. Msg 8606, Level 17, State 1, Line 1 This index operation requires 1024 KB of memory per ...
7
votes
2answers
8k views

SQL Server 2008 log files have minimum sizes, what gives and how do I make them smaller?

Ok, to start with, I screwed up when I created the databases, using a create script roughly like so: (artificial linebreaks and names/paths for wrapping purposes) CREATE DATABASE [EXAMPLE] ON ...
49
votes
8answers
119k views

How do I shrink all files quickly for all databases?

In SQL Server (2008 in this case) how can I quickly shrink all the files, both log and data, for all databases on an instance? I could go through SSMS and right click each and choose Tasks -> Shrink, ...
4
votes
2answers
2k views

How do I stop refresh conflicts between Proactive Caching of facts and timed refresh of Dimensions in a SQL Server Analysis Service 2005 OLAP cube?

I have a SSAS 2005 OLAP cube which we've very nearly made into a ROLAP cube using a mixture of proactive caching for the fact partitions and timed refreshes for the dimension data. There are two fact ...
27
votes
4answers
66k views

How to change SQL Server collation

How could I change the SQL Server 2008 R2 Express Default Collation for the whole server and a particular database? Is there a way to do it using visual interface of SQL Server Management Studio? In ...
26
votes
3answers
33k views

Code to simulate deadlock

I am testing my application I need some code that stable simulates the deadlock on database site (sql script if possible). Thank you. ADDED: Reproducing deadlocks involving only one table
8
votes
2answers
1k views

Is this a new common pattern in Oracle Where exists ( Select NULL FROM…)?

Years ago, it was common to write where exists (Select * from some_table where some_condition) Last year I noticed that many t-sql scripts switched to using the number 1 instead of the star where ...
15
votes
5answers
11k views

Does it make sense to use SQL Server's bracket notation in hand written code?

Code generators tend to be simpler when they generate output using the new Microsoft bracket notation ([]) for nearly everything. When I first saw it, I though wow a reincarnation of the somewhat ...
120
votes
8answers
90k views

Guid vs INT - Which is better as a primary key?

I've being reading around reasons to use or not Guid and int. int is smaller, faster, easy to remember, keeps a chronological sequence. And as for Guid, the only advantage I found is that it is ...
25
votes
3answers
5k views

Which collation should I choose for a muiti-language website?

Does a collation have any influence over a query speed? Does the size of a table change depending of the collation? If I want to build a website that must support all possible languages (lets take ...
13
votes
1answer
1k views

SQL Server - How are data pages stored when using a clustered index

I recently heard that the data pages in a clustered index aren't stored contiguously. Is this true? Perhaps data pages are normally stored contiguously with some exceptions to the rule? Or perhaps I ...
22
votes
2answers
2k views

Do I need separate indexes for each type of query, or will one multi-column index work?

I somewhat know the answer to this question already, but I always feel as though there is more I need to pick up on the topic. My basic understanding is that generally speaking, a single index that ...
216
votes
6answers
89k views

When should I use a unique constraint instead of a unique index?

When I want a column to have distinct values, I can either use a constraint create table t1( id int primary key, code varchar(10) unique NULL ); go or I can use a unique index create table t2( id ...
57
votes
6answers
70k views

What are the main causes of deadlocks and can they be prevented?

Recently one of our ASP.NET applications displayed a database deadlock error and I was requested to check and fix the error. I managed to find the cause of the deadlock was a stored procedure that was ...
115
votes
6answers
123k views

How to determine if an Index is required or necessary

I've been running an auto-index tool on our MS SQL database (I modified a script originating from Microsoft that looks at the index statistics tables - Automated Auto Indexing). From the stats, I now ...
6
votes
2answers
2k views

Dropping duplicate|redundant Unique Constraint from FILESTREAM table

I have a table with a FILESTREAM column, and it has two unique constraints specified for the same FILESTREAM column, ie: ALTER TABLE [dbo].[TableName] ADD CONSTRAINT [...
3
votes
1answer
1k views

SQL 2005: logical consistency-based I/O error: incorrect checksum

I got this error this morning during the execution of a SSIS package: SQL Server detected a logical consistency-based I/O error: incorrect checksum (expected: 0x5fb84eb5; actual: 0x7fb84eb5). It ...
38
votes
2answers
116k views

How do you stop, take offline, and delete a SQL Server database in recovery?

I have a development database which has entered recovery mode on restart, and has been recovering for the last hour or so. I need to either stop the recovery, or kill it in some way. I don't care ...
5
votes
5answers
21k views

How do I restore a SQL Server 2000 database to a SQL Server 2008 instance?

How do I restore a SQL Server 2000 database to a SQL Server 2008 instance?
2
votes
1answer
3k views

SQL Server 2005 query erroring with message 7105, slot for LOB data type node does not exist

SQL Server 2005 sp3 Standard on 64-bit Windows Server 2008 inconsistently receiving an error that seems to indicate corruption select * from some_table where text_field like ‘%the fox did not go ...
0
votes
1answer
135 views

SQL Server Point in Time Restore Scenario

Hopefully you can help out on this as I may be up a creek! I am working with a database using the FULL recovery model. The database has had nightly database backups but their transaction log has ...
7
votes
4answers
7k views

When is a full table scan better than index scan?

What are some scenarios (in SQL Server) in which a full table scan is better than an index scan?
4
votes
1answer
7k views

Sql FILESTREAM garbage collection issue

Updated 3x I'm using FILESTREAM, but am having an issue with garbage collection. The FILESTREAM files are not being cleaned up when I set the column to null. In the event log, there is an enormous ...
5
votes
1answer
879 views

Query Execution Time

I am querying a SQL server 2008 database table having more than 500 million records. The query I fired to move around 10 million records to temp table took 9 hours. Similar query I fired which has ...
2
votes
2answers
338 views

What is wrong in debunking myths about clustered indexes?

What is wrong in code. or its results, illustrating that clustered index is evil [1]? and how to de-debunk, i.e. to return to customary myths and best practices? [1] Debunking myths about ...
9
votes
2answers
1k views

Clustered indexing is now must - why?

Earlier, there were non-conclusive to me debates / discussions on whether to (always) engage / avoid clustered indexes. Well, I understood that they are to be used sometimes with proper + specific ...
2
votes
1answer
513 views

SQL Server Assertion Error

Does anyone have a solution to this problem? SQL Server Assertion: File: , line=10850 Failed Assertion = 'GetLocalLockPartition () == xactLockInfo->GetLocalLockPartition ()'. This error may be ...
4
votes
2answers
612 views

Bizarre crash in T-SQL - what is it?

What would be a typical situation under which the following error would occur, and what does it mean? Also note that I find myself disconnected from the server when the query fails (but I have not ...
1
vote
2answers
4k views

Repair a SQL Server 2000 MDF file

I had a SQL Server 2000 MDF on a SQL Server 2005 server (moved from prior version), there was a hardware failure. After sending harddisk, it was supposed the mdf / ldf files were recovered, but I am ...
6
votes
2answers
529 views

SQL Filegroup degrading performance

On our dev boxes, our database resides entirely in the PRIMARY filegroup, and everything works fine. On one of our production servers, recently upgraded from 2005 to 2008, we noticed it was ...
5
votes
2answers
10k views

SQL Server 2008 DBCC Problems

We have a database Ms DBCC CHECKDB (MS) Or ALTER DATABASE MS SET SINGLE_USER DBCC CHECKDB(MS,REPAIR_ALLOW_DATA_LOSS) ALTER DATABASE MS SET MULTI_USER Error message Msg 0, Level 11, State 0, Line 0: ...
7
votes
3answers
87 views

Does SQL Server guarantee accurate data storage? If so, how?

This question is specific to SQL Server, but other DB replies welcome. Read below for some history. My short question is, how does SQL Server guarantee that when I request "ABCDE" to be written to ...
5
votes
3answers
157 views

Interpreting an execution plan

I need some help analysing some simple t-sql execution plans. I have a table [User] with the following 3 columns: Id(Primary Key), Username(nvarchar(50)), FirstName(nvarchar(50)) I have Created an ...
35
votes
3answers
56k views

What is the difference between Shrink Database and File?

DBCC ShrinkDatabase() DBCC ShrinkFile() Do I need to run both DBCC commands in order to shrink the database? What is the difference between these two above?
10
votes
10answers
17k views

Shrink a database below its initial size

I've got a SQL server 2005 dev database that is a 30GB copy of live. We have deleted some data that is not needed in dev, which brings the data file space used down to 20GB. So we have about 33% ...
2
votes
1answer
2k views

Exclude .LOG file while restoring a database

I have a database backup file (MyDatabase.bak). When restoring the database through SSMS it gives me "Not enough space on disk" message. I looked for an option to exclude .LOG file from restore but ...
14
votes
3answers
11k views

SQL Server - Temporary vs. Physical Tables

A movement is afoot in my place of employ to move away from using #temp tables and instead to use permanent physical tables with SPIDs. Whenever one would have previously INSERTed INTO a #temp table, ...
12
votes
3answers
18k views

Performance hit using CAST in T-SQL

We have a SQL generator that emits SQL conditional statements generically for specified fields (which for the sake of discussion: we will label as myField). If myField is of type NVARCHAR, we can ...
4
votes
1answer
980 views

DBCC CHECKDB WITH DATA_PURITY gives out of range error

I have restore a SQL Server 2000 database onto SQL Server 2005 and then run DBCC CHECKDB WITH DATA_PURITY and I get this error: Msg 2570, Level 16, State 3, Line 2 Page (1:19558), slot 13 in object ...
2
votes
1answer
351 views

SQL Server DB Restore Clustered to Single Node?

Can you restore a DB from a SQL Server 2005 Clustered Environment (Prod) to a single server (single node) (SQL Server 2005) in Dev/Sys? Cheers, Conor
7
votes
3answers
10k views

Howto use Windows Authentication with SQL Server 2008 Express on a workgroup network?

I have two computers running SQL Server 2008 Express: c01 and c02, I setup both for remote connection using windows authentication. Worked fine for c02 but not for c01. This is the error message I'm ...
20
votes
5answers
7k views

Using IF in T-SQL weakens or breaks execution plan caching?

It has been suggested to me that the use of IF statements in t-SQL batches is detrimental to performance. I'm trying to find some confirmation or validate this assertion. I'm using SQL Server 2005 ...
5
votes
3answers
4k views

Should I be regularly shrinking my DB or at least my log file?

My question is, should I be running one or both of the shrink command regularly, DBCC SHRINKDATABASE OR DBCC SHRINKFILE ============================= background Sql Server: Database is 200 ...