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1
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3answers
70 views

Update statistics for all databases all tables in a server

Hi I have been working on a script to update statistics of all tables on all my DBs. The idea is to parametrise it later on, but just as a quick fix, and not wanting to implement Ola's scripts today, ...
2
votes
2answers
35 views

How to tell which indexes are not being used

Postgresql 9.3 Debian 7 I have a lot of huge indexes in a legacy database I'm trying to optimize. Thinking about dropping all the useless ones, but how can I tell how often they are used and if they ...
1
vote
0answers
14 views

MySQL: index statistics dropped when table dropped?

When a table is dropped, are its index statistics also removed? The reason I ask is that I was hoping to 'prep' the stats by running log playback via the percona-playback tool prior to cutting over ...
9
votes
1answer
377 views

Poor query performance

We have a large (10,000+ lines) procedure that typically runs in 0.5-6.0 seconds depending on how much data it has to work with. Over the past month or so it has started taking 30+ seconds after we do ...
3
votes
1answer
2k views

What's the impact of running sp_updatestats in production server?

Is it safe to run sp_updatestats on an SQL Server in the production environment? Or rather, what is the impact of updating all statistics on a sql server? Can it "choke" the sql server while it runs ...
1
vote
2answers
118 views

For merge replication, do I need to schedule index maintenance on all sites or just publisher?

I have a very fragmented database that uses merge replication with remote sites. Do I need to schedule index maintenance (reorganize / rebuild) for all sites? Or just on publisher copy?
2
votes
3answers
173 views

how to trigger a statistics update

I have a certain table in my OLTP database, which is bulk-updated by several users. There is no way to know when they will update the table (somewhere between 5 times a day and once in a week). The ...
2
votes
0answers
325 views

Oracle 11g bug ? not returning the record until I triggered index to invisible and then to visible

We are using Oracle 11g, 11.2.0.3. We know a record exists in a table but a select is not returning it for some odd reason. The execution plans the general query, not forcing any index, shows that ...
3
votes
1answer
48 views

SP with Encryption Read/Writes Stats

If a stored procedure in SQL Server 2005 is created with the syntax "WITH ENCRYPTION" ,are the reads and writes of the encrypted stored procedure recorded in the sys.dm_db_index_usage_stats? I am ...
3
votes
1answer
379 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 ...
4
votes
1answer
79 views

Index Evaluation

I have been doing some index evalaution on a table and this is the first time I have ever looked at how well indexes are performing so and would like some advice on a certain index. The non ...
0
votes
2answers
79 views

Indexing is not working

Following is the table and index information for which I have the queries at the end. Create Table: CREATE TABLE `food` ( `id` int(10) unsigned NOT NULL DEFAULT '0', `page_no` int(11) DEFAULT ...
3
votes
3answers
172 views

What is a good guideline for sampling for statistics updates

Scope: A billion record table that is indexed in 10 ways. Rate of change per day is 1/2 a percent. Some of the indexes are monotonously increasing (datetime/timestamp), yet the common queries most ...
4
votes
1answer
274 views

Check Index Fragmentation on SQL Server Audit Queues

I've read this excellent article, http://rusanu.com/2010/03/09/dealing-with-large-queues/, and seem to be having the same issue, due to a low space issue, the service broker was turned off on a ...
5
votes
1answer
644 views

Difference between idx_tup_read and idx_tup_fetch on Postgres

On Postgres 8.4 when you do: select * from pg_stat_all_indexes where relname = 'table_name'; It returns the fields idx_tup_read and idx_tup_fetch, what is the difference?
1
vote
1answer
328 views

Analyzing TCB Index Status for DB2

The Following is the TCB index that I could get using a command for my DB2 database. I don't know how to analyze it. Which columns are important? What do they mean? TCB Index Stats: Address ...
0
votes
0answers
574 views

Update Statistics Maintenance Plan - Ambiguous column name error

Microsoft SQL Server 2008 R2 Web Edition (RTM) - 10.50.1600.1 (Intel X86) Windows 2003 R2 SP2 I am in the process of setting up a maintenance plan to update statistics on a daily basis for all user ...
1
vote
2answers
176 views

How to retrieve the definition behind statistics added to tables

Is there a way to programmatically retrieve the definition of each STATISTICS added to table columns and indexes. For both user added and system created indexes. There are many STATISTICS like ...
8
votes
3answers
6k views

MySQL status variable Handler_read_rnd_next is growing a lot

In MYSQL status, Handler_read_rnd_next value is very high. I am aware that, this value will be incremented when a query is executed which is not having proper indexes. But, even when we execute ...
10
votes
6answers
2k views

Reasons for disabling statistics auto update?

I just learned that a client company I work for has decided to keep the auto update statistics options off for some of their SQL Servers, and the DBAs manually troubleshooting performance issues when ...
2
votes
1answer
165 views

Is this Index checking logic ok?

I am writing a script to quickly check the indexes in a given database. I think I have the script written ok but to remove duplicate rows I have done alot of SUM functions and I am unsure whether this ...
1
vote
2answers
229 views

dm_db_missing_index_details - does the order of equality_columns matter

I've been investigating some databases using the dm_db_missing_index_group_stats DMV, and have a question about the equality_columns field in the dm_db_missing_index_details view. MSDN says that this ...
7
votes
3answers
4k views

From where does the MySQL Query Optimizer read index statistics?

I'm trying to determine from where the MySQL optimizer obtains the list of indexes that are available for a table when it estimates the cost of (prepares) a query from.