Tagged Questions

6
votes
3answers
157 views

Are SQL Server statistics stored in database or buffer pool?

Just wondering are statistics kept in the database but not in the memory? If I backup/restore the database from a prod server to a development server, would it keep the same statistics so that ...
3
votes
1answer
57 views

Does creating / updating statistics have an impact on the transaction log?

Does creating or updating statistics, assuming on a large table, create significant (or at all) transaction log churn? I would think not as it does not change the underlying data or structure. If it ...
1
vote
2answers
81 views

sql server 2008 execution plan different on two production servers

We have two servers running SQL server 2008 R2, with identical databases, where we implemented a datawarehousing solution. The cube processing operation was taking a VERY long time in one of the ...
2
votes
1answer
84 views

Query requires 'Update statistics' very often in SQL Server

We have a few tables in our database. Since most of our queries are date based, we have constructed clustered index on 'date + primary key (surrogate)' combination and we enforce joins on date as well ...
7
votes
1answer
108 views

How does sampling work when updating statistics?

I have several massive tables. I'd like to ensure their statistics are up to date via a weekly maintenance plan. However, doing so is taking too much time. If I specify WITH SAMPLE 50 PERCENT ...
7
votes
1answer
183 views

SQL Server Index vs Statistic

What are the differences between CREATE INDEX and CREATE STATISTICS and when should I use each?
2
votes
2answers
190 views

Problem with sp_Updatestats

I am having a problem when running sp_updatestats on my database it generates an error when my emp table is updating and disconnects I will paste the error here Updating [dbo].[emp] Msg 0, Level 11, ...
6
votes
1answer
178 views

AUTO_UPDATE_STATISTICS_ASYNC ON?

I have been advised that setting the AUTO_UPDATE_STATISTICS_ASYNC ON may be a good idea. I have been reading a couple of ideas and still not sure as this is a non default setting. Any further ...
1
vote
1answer
173 views

SQL Server 2008 R2 - Weekly / Monthly Statistics

I'm new working with SQL Server 2008 R2 Express, and I´d like to gather some statistics every week / month for users who are connecting to this server. For instance, how many times they were ...
2
votes
2answers
262 views

Parallel Statistics Update

In SQL Server 2008 or later, is UPDATE STATISTICS WITH FULLSCAN a single threaded operation or it can use parallelism? How about update statistics with default sampling - can it use parallelism? I ...
7
votes
2answers
2k views

When To Update Statistics?

I've inherited a Maintenance Plans that does the following: Cleanup old data Checks DB integrity Performs Database and Transaction Log Backups Reorganizes Our indexes Updates Statistics Delete old ...
3
votes
1answer
437 views

Executing the query “UPDATE STATISTICS [dbo].[Contact] WITH FULLSCAN …” failed

My maintenance plan fails with the following error on one of my databases does anyone know how I can fix this problem? is is a corrupt table? Executing the query UPDATE STATISTICS [dbo].[Contact] ...
7
votes
1answer
194 views

Tracking stored procedure usage

Besides using SQL Server Profiler, is there any way to track which stored procedures are being used, or at least when they were last executed?
7
votes
3answers
2k views

Is there a reason to update statistics manually?

In SQL Server, statistics are updated automatically when Auto Update Statistics in True (which is the default). Is there a reason to update statistics manually and in what circumstances?
6
votes
2answers
211 views

What can cause statistics to get out of line?

I've just worked through a problem at a clients site which it turned out was caused by the statistics being wrong which caused the Optimizer to time out. Running exec sp_updatestats fixed the problem ...
2
votes
2answers
237 views

How do I replicate SQL Server index INCLUDE and STATISTICS functionality on PostgreSQL?

I'm working on a project that must support two database engines; SQL Server and PostgreSQL. We are using NHibernate as the ORM. We are running into performance issues with certain queries. Using ...
2
votes
2answers
445 views

SQL Server: Do Statistics Updates cause query plans to be flushed? Should they?

I've found that a big, nasty data-extraction query that runs daily needs updated stats to avoid making horrible query plans based on incorrect rowcount estimates (let's not worry about whether or not ...
5
votes
2answers
147 views

If a query triggers a statistics update and times out are the statistics still updated?

I have a fulltext query which is usually very fast but may time out when it causes a statistics update since statistics updating is very slow on this database. Usually the query "recovers" to normal ...
1
vote
1answer
559 views

Estimated vs. Actual rows and multi-column statistics

I'm trying to understand multi column indexes and statistics, here is my real world example: Table: TaskExecutions, size=~1 million rows. Query SARGS: TaskExecStatusID = 3 AND TaskExecUpdatedDate IS ...
5
votes
2answers
274 views

Get NULL statistics for a column in MS SQL Server

In MS SQL Server 2005, how can I extract statistical information about NULL fraction (or NULL count) for a given column? Same information is available in Oracle and PostgreSQL, and I heard that MS ...
5
votes
2answers
485 views

DTA Recommends to CREATE STATISTICS

I just ran a T-SQL query through DTA and one of the recommendations is to CREATE STATISTICS on one of the columns that is part of many of the queries in the SQL code file. My question is, how exactly ...
6
votes
5answers
2k views

SQL Select taking too much time to execute

It's a simple select from a temporary table, left joining an existing table on its primary key, with two sub selects using top 1 referring the joined table. In code: SELECT TempTable.Col1, ...