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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How do I run a large script with many inserts without running out of memory?

Question: I have a script with around 45 thousand insert from select statements. When I try and run it, I get an error message stating that I have run out of memory. How can I get this script to run? ...
14
votes
5answers
8k views

Does restarting SQL Server speed it up?

I have noticed that some DBAs restart SQL Server very frequently, sometimes even nightly. I believe they do it to free up some memory, or perhaps to speed up queries too. I know that after a restart ...
13
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6answers
33k views

How to efficiently check EXISTS on multiple columns?

This is an issue I come up against periodically and have not yet found a good solution for. Supposing the following table structure CREATE TABLE T ( A INT PRIMARY KEY, B CHAR(1000) NULL, C ...
13
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1answer
1k views

What's the anatomy of a columnstore index?

One of the new features in SQL Server 2012 codenamed Denali is the Columnstore index. I know a good bit about regular old row-store indexes, like the b-tree structure, differences in storage between ...
12
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2answers
2k views

Storing massive amounts of data from a sensor array

I have been tasked to implement a solution (app and db) to store the data samples from a huge sensor array. The array currently consists of about 20,000 sensors, but that is soon going to grow, up to ...
11
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2answers
709 views

Understanding MS SQL Server encryption and backups

So I was asking in chat about how secure SQL Server backup files are. I'm told that if an attacker has access to the .bak file unencrypted that they can have access to the data. So lets look at ...
11
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1answer
2k views

Why is Clustered Index Scan Number of Executions so high?

I have two similar queries that generate the same query plan, except that one query plan executes a Clustered Index Scan 1316 times, while the other executes it 1 time. The only difference between ...
11
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5answers
2k 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 ...
10
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2answers
913 views

Optimization: Moving variable declarations to the top of your procedure

While working on optimizing some stored procedures, I sat down with the DBA and went through some sprocs with high blocking and/or high read/write activity. One thing the DBA mentioned was I should ...
9
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2answers
4k views

Why are non-digits LIKE [0-9]?

My server's default collation is Latin1_General_CI_AS, as determined by this query: SELECT SERVERPROPERTY('Collation') AS Collation; I was surprised to discover that with this collation I can match ...
9
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1answer
2k views

Interpreting SQL Server's Showplan XML

I just rolled out a feature on my site http://sqlfiddle.com that allows users to view the raw execution plans for their queries. In the case of PostgreSQL, MySQL, and (to some extent) Oracle, looking ...
8
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1answer
132 views

Visualizing SQL Server Extended Events data

Lately I've been exploring using Extended Events in SQL Server to help me benchmark and optimize various queries. So far, to view the event data I have been using the "Watch Live Data" feature in ...
8
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5answers
752 views

Does SQL Sentry Plan Explorer work?

Does SQL Sentry Plan Explorer work as advertised and is it legitimate? Are there any gotchas or something to be concerned about? It looks like it shows the hot path in color commpared to SSMS's ...
7
votes
1answer
705 views

Equality query on NVARCHAR column yields multiple results in SQL Server 2012

I am in the process of moving a pet project from PostgreSQL (9.2.2) to SQL Server (2012 Standard). I've noticed an interesting phenomenon when querying unicode words. Given the definition: CREATE ...
7
votes
1answer
1k views

What factors go into an Indexed View's Clustered Index being selected?

Breifly What factors go into they query optimizer's selection of an indexed view's index? For me, indexed views seem to defy what I understand about how the Optimizer picks indexes. I've seen this ...
7
votes
3answers
9k views

Improve performance of sys.dm_db_index_physical_stats

During a maintenance job, I'm trying to get a list of fragmented indexes. But the query is extremely slow and takes over 30 minutes to execute. I think this is due to a remote scan on ...
7
votes
3answers
5k views

Performance Hit using CAST() in TSQL (SQL Server)?

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). So, if myField is of type NVARCHAR, we ...
7
votes
4answers
2k views

Slow temp table drops in sql 2005

I've run into a problem on our production sql server where temp table objects take a long time to drop (obvious when small and synchronous drop is used). I can't reproduce this on other sql servers ...
7
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6answers
3k views

Pros and Cons of SQL Server back up strategies and their appropriate usage scenarios

From what I can tell, there are three possible ways of backing up your SQL Server database Full backup Differential backup Log Shipping What are the pros and cons of each strategy and in what ...
6
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2answers
426 views

Filter table before join

I have a stored procedure that populates the temp table #employee_benefits with a list of Ids. This table ends up being roughly 10,000 rows long. The query below then selects from a table called ...
6
votes
2answers
4k views

How to optimise T-SQL query using Execution Plan

I have a SQL query that I have spent the past two days trying to optimise using trial-and-error and the execution plan, but to no avail. Please forgive me for doing this but I will post the entire ...
6
votes
2answers
6k views

Transaction and Try-catch in SQL Server Job

We have DML operations in each step of a SQL Server job. To ensure the update/insert will be rolled back in case something goes wrong, I have wrapped the data modifications of each step in TRY CATCH ...
6
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1answer
522 views

How much memory is a table taking up?

Is there a way to find out how much memory a table is taking up in SQL Server (2005 and greater)? For example, suppose I have a table with 30 million records. I'd like to know how many pages ...
6
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1answer
6k views

Restore encrypted database to another server

I'm using a product which runs on SQLServer 2008. Understandably the company supplying it don't offer SQLServer support. When I installed the product I specified a password to encrypt the database. ...
5
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2answers
438 views

When was a Database taken Offline

I am trying to find a way to figure out when was couple of my sql databases were taken offline. I checked the the logs but could not find any such info and moreover there is no default trace enabled. ...
5
votes
2answers
8k views

SAN block size for SQL Server on 4KB NTFS

A potential customer wants to evaluate our storage system. They run Windows 2008R2 x64 with 4KB NTFS on a virtual test machine they've sent us. They did not seem to know this at hand, so I think it's ...
5
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1answer
8k views

Give permission to select from system tables

I have a database Microsoft SQL Server 2008 r2. A user called marie is defined, who can access tables on the main database; this works well. Now, I would like marie to be able to perform this query: ...
5
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2answers
9k views

SQL 2008 R2 creates user/schema when Windows user creates tables

We added a server login and database user that map a Windows Group to a SQL 2008 R2 instance using the following script, with the names changed for anonymity: USE master go CREATE LOGIN ...
4
votes
1answer
278 views

How to avoid using Merge query when upserting multiple data using xml parameter?

I am trying to update a table with an array of values. Each item in the array contains information that matches a row in a table in the SQL db. If the row already exists in the table, we update that ...
4
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1answer
106 views

Proving the usefulness of a specific index

I'm looking for a way to prove that some recently added indexes are positively impacting a production system. I've collected some dmv statistics to show that the indexes are indeed being used ...
4
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1answer
1k views

CREATE DATABASE permission denied for sysadmin

I'm attempting to create a stored procedure that can be used as a proxy for creating databases where users do not have rights for creating databases. See Restricting Database Access/Functions to User ...
4
votes
1answer
3k views

How to force the use of row locks?

I am trying to get my table to use row locks. I have already disabled lock escalation. The isolation level is READ_COMMITTED_SNAPSHOT alter table <TABLE_NAME> SET (LOCK_ESCALATION=DISABLE) go ...
4
votes
3answers
4k views

Datawarehouse Design: Combined Date Time dimension vs. Separate Day and Time dimensions and timezones

We are just starting design for a new data warehouse and we're trying to design how our date and time dimensions will work. We need to be able to support multiple timezones (probably at least GMT, ...
3
votes
1answer
568 views

Running functions in parallel

This is for SQL Server 2012. We have some import processes for FTP files that are picked up and read into a staging table, from there we massage/check the data before moving into production. One of ...
3
votes
2answers
2k views

Can I optimize this MERGE statement?

I am attempting a single column merge between two tables. The first table (VisitorSession) has 40,000,000 rows. The second (ShoppingCart) has 9,000,000 rows. In my development environment, the query ...
3
votes
2answers
552 views

Help with a multi-language medical database

My project is to design a database for medicines in many countries. Medicines have various criteria like composition, price, manufacturer. Database will be multi-language; related to each country. ...
3
votes
2answers
2k views

TdsInputBufferError not 0 in LoginTimers errors of RING_BUFFER_CONNECTIVITY of sys.dm_os_ring_buffers

I've got an issue with SQL Server. The value of TdsInputBufferError is not 0 in LoginTimers errors of RING_BUFFER_CONNECTIVITY of sys.dm_os_ring_buffers. This happens randomly, once or twice a week, ...
2
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1answer
2k views

Transactional replication altering tables and adding stored procedures

I have a database that is replicated in several locations. It is setup as transactional replication. However, now I need to add more columns to the table. Add more stored procedures and etc. Hence, if ...
2
votes
3answers
1k views

Working Linked Server Query fails in sp_send_dbmail

Take the following example: EXEC msdb.dbo.sp_send_dbmail @recipients = 'me@whatever.co.uk' , @query = 'SELECT TOP 10 * FROM LINKEDSERVERA.DATABASE.dbo.TABLE' , @attach_query_result_as_file = N'True' ...
2
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2answers
3k views

SQL Server replication subscriptions marked as inactive

Is there any way to force SQL Server NOT to mark subscriptions as inactive, ever? It happens sporadically when there are connection issues and I don't want to have to reinitialize the subscription ...
2
votes
1answer
498 views

Understanding SQL Server encryption (by password)?

After asking this I still have a question. A company need to store sensitive data. Please let's not talk about certificate right now. A DBA does the following : CREATE SYMMETRIC KEY ...
2
votes
2answers
3k views

Restore Database script

I have a live database which i would like to create a backup and restore script that will take the "live" database every night, create a back, then drop the existing "testing" database (if any) and ...
1
vote
2answers
858 views

“In Use” memory on a SQL Server box

I have a SQL Server 2012 database server with 64GB of RAM. A process called DataPumpService runs on the same box and loads around 400 million records from 2700 flat files. I want to understand what ...
0
votes
3answers
509 views

Can a RDBMS connect to a remote server, execute a select query and copy them into a local table just with SQL commands?

I'm sorry it may sound stupid but I've been wondering about how multiple databases are automated before the virtualization era. Can a DB Adminsitrator make a stored procedure to get data from a remote ...
-6
votes
3answers
966 views

SQL Server Express with 20000 databases won't start

I have a SQL Server Express instance with 20,000 databases (twenty thousand databases).. and the service won't start. I get error message 1053: The service did not respond to the start or ...
16
votes
4answers
11k views

What is the best query to use to monitor a SQL Server database's status?

I want to be able to run a query to get the crucial information about a database's status. I.e., I want the query to be able to tell what whether or not the database is in a good state. This is the ...
15
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1answer
2k views

Where are Statistics physically stored in SQL Server?

Where are the Statistics used by the Query Optimizer physically stored inside a SQL Server database file and the Buffer Pool? More specifically, is there a way to figure out the pages used by ...
15
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3answers
3k views

Anybody using HierarchyId in production? Is it reliable?

Is anybody using HierarchyId in real production with tables of reasonable size, more than a few thousand rows? Is it reliable/performant? So far I have not found anyone not affiliated with the vendor ...
14
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1answer
8k views

How do I read Query Cost, and is it always a percentage?

I'm currently studying for SQL 70-433 (the Microsoft Certification exam), and I'm getting very confused about the "query cost" performance metric. According to any documentation I could find via ...
13
votes
3answers
20k views

Can I use SQL Server Management Studio 2012 on a 2008 server?

My school is using SQL Server 2008. Last time I used it I only installed (at home) SQL Server Management Studio 2008 part, and used VPN to connect to school's server. Now I want to install SQL Server ...