The discipline of Operational and Architectural Management of Database Systems.

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Rebuilding index has impact on mdf/ldf files SQL Server 2008

While rebuilding index have used option 'SORT_IN_TEMPDB = ON' in order to avoid unnecessary growing your user database files. What does it exactly means? Is complete process done on TempDB and does ...
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1answer
836 views

Does dropping a Primary Key constraint from a Partitioned Table break the partition?

We have a table partitioned on a date column. The Primary Key for the table is a composite key of this date column and 4 other columns. We are thinking about dropping the Primary Key constraint from ...
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23k views

How to create Sql Server login for a domain account?

All, I have Sql Server 2008 installed on a server (let's say Server1) in a Domain (let's say AD). I also have a domain account called AD\Sql1. This is not an Admin account on the Domain (AD), but I ...
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2answers
361 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. ...
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1answer
286 views

Why not rebuild indexes with page count <1000?

I use Ola Hallengrens script for Index maintenance. Before I did that, I used the following query to see which indexes are fragmented most: SELECT dbschemas.[name] as 'Schema', dbtables.[name] as ...
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1answer
206 views

How do I track logins, connections, user accounts, queries, …?

I am a BI person who has been asked to step in and pretend I am a DBA. I am not a novice with databases but AM a novice at the admin type stuff. We have a SQL Server database that is going to be ...
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1answer
502 views

Expanding a partitioned table

I have a table that holds four years of data, where for each month I have a partition that is based on a filegroup with two files. Unexpectedly, I received eight more years of data and prepared the ...
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3answers
330 views

Bad use of Oracle Tablespaces

I have a doubt about the use of oracle tablespaces. I've decided to define for each schema of the datababase two different tablespaces (one for data, and another one for indexes). The problem is that ...
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1answer
3k views

Appending backups while overwriting expired sets

I've been reading up on this, but the online documentation is a bit difficult to understand and seems awkwardly written. For example the INIT, NOINIT. One says it will try to overwrite everything. ...
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2answers
229 views

What are sensible/rational character limits in a database e.g. for a persons name

This is a general question about database admin. Is there some kind of standardization for character limits on fields in a DB? It makes sense to specify character limits on the database end for ...
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2answers
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What is the point of the TABLE_CATALOG column in INFORMATION_SCHEMA.TABLES?

In MySQL's table INFORMATION_SCHEMA.TABLES, there's a column named 'TABLE_CATALOG'. The documentation is sparse on this column and I'm wondering what the heck is the purpose of this? Any killer-app ...
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2answers
132 views

Is it somehow possible to predict / foresee when SQL Server will trigger auto-growth?

I found numerous questions / answers about SQL-Server auto-growth - almost all indicating that one should try to avoid auto-growth if possible. However auto-growth is available with MS SQL Server and ...
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1answer
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Mongo Collection `Size` is *larger* than `storageSize`?

I recently compacted my collection using the command: db.<collectionName>.runCommand( "compact" ) And now my collection size seems to be bigger than size on disk! SECONDARY> ...
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1answer
285 views

Is there a standard approach to rolling out database schema changes?

A developer said I should simply wrap all my database upgrade scripts in a transaction. If it fails, just roll back all changes. All my instincts tell me this is wrong, especially when it comes to ...
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1answer
698 views

Does PgBouncer create a separate pool for every database config entry?

If I set up a pgbouncer.ini config file with several database entries, does pgBouncer create a separate pool for each one? I would think so, but have not been able to confirm this. For example, ...
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2answers
527 views

How to properly configure PostgreSQL RAM usage?

Using PostgreSQL, we have several hundred concurrent processes doing regular database access. We have our data spread out through several database servers, each of which houses a connection pool with ...
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2answers
433 views

SQL Server - DBO without Backup

Similar to my previous Question : Prevent Non Copy Only Backups, how do I create a user that can do everything to my database take backups at all. I've granted them every role except ...
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1answer
102 views

SQL Server 2012 Unable to Utilize Defined Amount of Locks

So I've been beating my head against the wall for two days about this and I can't find a solution. I'm running a script to stage a large amount of data. This script requires roughly 35 million locks ...
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1answer
3k views

Could too many idle connections affect PostgreSQL 9.2 performance?

Some queries on my database server seem to take a long time to respond, and I believe the CPU usage is high. When running ps aux, I see ~250 "idle" connections (which I believe to be too many). I ...
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2answers
7k 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 ...
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3answers
4k views

How to reduce the log file size without shrinking it in SQL server

In SQL server, how do you reduce the log files size without (DBCC) shrinking it. I know shrinking the log file will free up some space, but will also cause fragmentation. Doing a checkpoint in simple ...
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4answers
438 views

Recommendation for free event monitoring software

I'm seeking recommendations for free / open event monitoring tools. HPOV costs continue to multiply like so many wet gremlins, and we've had enough. There are some interesting suggestions in this ...
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1answer
3k views

ERROR: database “dbname” does not exist

According to the documentation, so long as I'm not connected to a database, I can either delete a database in the console using: DROP DATABASE dbname; Or I can drop it using the wrapper tool ...
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2answers
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One filegroup, multiple datafiles, how to get list of tables in each file

In one of my production databases, I have a filegroup with 3 data files sitting on 3 different disks. There are over 50 tables on this filegroup. How do I identify the location of each of the 50 ...
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2answers
12k views

How to backup IBM DB2 Database online?

I tried to backup the IBM DB2 (LUW) Database using this command: ./db2 backup database DBEMP to /home/user1/db2bkup But I got this message: SQL1035N The database is currently in use. ...
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702 views

Update Statement takes forever to complete [closed]

I have table around 1250000 records, and 80 columns Table Structure CREATE TABLE [dbo].[Table] ( [Column1] [int] IDENTITY(1, 1) NOT FOR REPLICATION NOT NULL, [Column2] [int] NULL, [Column3] [int] ...
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3answers
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How can I dynamically back up all SSAS databases on a given instance?

I want to dynamically back up all the databases on a given SSAS instance using a SQL Agent job (which would most likely involve executing an SSIS package). It is imperative that this is a dynamic ...
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3answers
18k views

Oracle 11g - Create Database fails?

I've just installed Oracle 11g and linked it to SQL Developer. I want to create a database for my django install. CREATE database 'django'; Error starting at line 1 in command: create database ...
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2answers
1k views

Creating partitions on a production database

I have a production MySQL 5.1 database that is running well but I want to improve query performances. I have never used Partitions and just going through the manuals. I have two tables that involve a ...
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3answers
2k views

How can I enter Mongo as a superuser or reset users?

I'm was playing around with permissions and locked myself out of Mongo database. I'm pretty sure I did this by trying to explicitly add access to a database but instead I overwrote only allowing ...
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2answers
495 views

Why monitor bytes sent and received on mysql

I want to know why we should monitor bytes sent and received on mysql ? I hope I have not asked a vague question. Thanks.
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3answers
150 views

Can anyone describe the step by step process of recovery , backup and restore in sql server

Can anyone describe the step by step process of recovery via backup and restore in SQL Server 2008. If possible please include some examples.
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2answers
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How to Correctly Estimate the Average Number of I/O Operations my RAID 10 disk can offer?

The average Input/Output Operations per Second a disk can sustain is a very important factor in the tuning of MySQL / InnoDB databases, as it drives the speed with which Dirty InnoDB Buffer Pool pages ...
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1answer
383 views

Can I check what the allocation unit size is on my drives via a query?

Assuming that I do not have access to windows server, can I run a script from SSMS that would allow me to check whether allocation unit size is formatted with 64K?
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1answer
632 views

What are the concepts that need to be gone through for MySQL DBA?

I am a MySQL Developer, besides I am handling some DBA activities like backup, restore, mysql installation, etc at a top level. Now I wanted to shift to DBA, So I wanted to know in depth, like which ...
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2answers
3k views

mysql multi threading for a single query

I have big db of size 8GB and having 9 million contacts in this db. When we try to retrieve all contacts, it takes nearly 1 or 2 hour (in some cases result in timeout) to retreive all contacts for the ...
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1answer
661 views

Any way to send notifications to different Emails on success/failure of SqlServerAgent job?

SQL Server 2012 R2 on Windows Server 2008R2 Is there any way to send notifications to different Emails: on success of an Sql Server Agent job to one Email address and on failure - to another ? ...
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2answers
579 views

Isolation Level for a Data Warehouse

We are building out a data warehouse (and also some data marts as well) in our organization. My DBA skills have mostly been on OLTP type applications, but I am moving into supporting OLAP for our ...
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1answer
2k views

823 errors on tempdb

Have a couple Fiber channel SAN-attached cluster servers which have been intermittently reporting errors like: 2012-05-09 16:31:54.13 spid74 Error: 823, Severity: 24, State: 2. 2012-05-09 ...
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1answer
213 views

High amount of Read Misses and Pages To Be Flushed

I am running a mysql database backend for a Moodle installation, and after a few months performance really starts to suffer (Up to 30 seconds for some pages to load). Under investigation in the InnoDB ...
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1answer
176 views

After Rackspace server creation, PostgreSQL query planner doesn't work as expected

We created an image of one of our database servers in Rackspace. Then, we created a new server using that image, expecting things to work. However, the index performance we have seen seems to be ...
4
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1answer
103 views

How can I copy specific tables into one SQL Server Table into a separate table automatically?

I'm not sure if this is possible. Looking for some help with a specific issue. I am building an iPhone application with a data layer written in Ruby that will connect to SQL Server 2008. For various ...
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2answers
3k views

efficient way to poll database?

I have a Linux CentOS server hosting an Oracle 11.2 database, which communicates with an application server, which communicates with a client (a Flex application). I'll try to describe the pseudo-code ...
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2answers
2k views

How do you find home information for Oracle RAC on Unix?

Need help finding Oracle home path corresponding to a database instance in RAC environment. I am aware of few of the ways to achieve the same. Listing them below to avoid the same answers. ...
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1answer
2k views

When dedicated server process model should be used instead of shared process model?

It looks like Oracle shared server process model is better than dedicated server process model. In a shared server configuration, client user processes connect to a dispatcher and it can support ...
4
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1answer
383 views

Oracle AWR shows missing stats for SQL ID as top elapsed statement

Why SQL ID has null number of executions and elapsed time / execution in AWR report. SQL ID is among top elapsed command on AWR but no details stats whoing time / execution. Would it be because shared ...
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1answer
1k views

Take individual MySQL database offline

MySQL does not have any SQL commands or internal mechanisms for making an individual database unavailable / offline moving an individual database Thtis being the case, how can you take an ...
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How do I monitor bandwidth used by SQL Server on port 1433?

I have a single server running a .NET web application and a SQL Server database (2008 Standard). I'm planning to move the database onto a separate server but in order to provision the network hardware ...
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5answers
196 views

Does DBA need (a read) access to virtualization infrastructure? And why?

I am in charge of monitoring, troubleshooting, tuning and optimizing a few dozens production SQL Servers 2008 R2/2012 in my company that are being run inside VMWare virtual machines. I've requested ...
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2answers
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VACUUM and VACUUM FULL do not return space to OS

I'm running Postgres 8.3.3. I have a postgres database on a Linux filesystem that is quite full. I've run VACUUM and VACUUM FULL, yet none of the space has been returned to the OS. When I observe ...