The discipline of Operational and Architectural Management of Database Systems.

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5
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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> ...
2
votes
1answer
147 views

database connection time expired issue

I have a server machine and four client machine for database connectivity. I installed sqlexpress 2008 in server and one machine and all remaining systems, they have connected the database through ...
0
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1answer
85 views

Copy snapshot files from Publisher, Paste and Apply on subscriber in SQL Merge Replication

I read an excellent article about copying the snapshot files for Transactional replication from Publisher to Subscriber and Apply them on subscriber. ...
15
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2answers
3k views

Handling growing number of Tenants in Multi-tenant Database Architecture

Handling a modest number of customers (tenants) in a common server with separate databases for each tenant's instance of the application is relatively straightforward and is normally the correct way ...
5
votes
1answer
254 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 ...
2
votes
4answers
206 views

MySql Database solution for specific web app problem

Well, I need to create a comment system for posts that people add to my web app. This web app is just like facebook or myspace posts. Users add posts and people can comment on them. But the problem is ...
6
votes
2answers
213 views

Automation of backups of Large Number of Database

In a multi-tenant web application where a database is set up for each tenant, the database can be backed up and restored manually through a fairly conventional approach. I am considering this type of ...
2
votes
2answers
74 views

Data Backup and Restoring the same if requried in SQL SERVER 2008

In Multi-tenancy , Shared Database Shared Schema. How to take Tenant level backup and restored the tenant data when required? Can any one guide me or point me to the right direction. Thanks!!! NB: ...
7
votes
1answer
9k views

What exactly is binding in DB2?

I recently crossed over from being a Java developer to an actual DBA in our company. I am learning the ropes, so to speak, about being a DBA (which is actually somewhat of a new position for our ...
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1answer
2k views

How can I move LOB_DATA ( varbinary/image/text) to different Filegroups

LOB_DATA : varbinary(max),varchar(max), image , text columns. I have 4 tables with large amount of LOB_DATA in it. I would like to move LOB_DATA in these tables to different File group in a different ...
1
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1answer
1k views

Solution to error NID-00135 in Oracle 10g, Solaris 10

We are trying to build a test version of a production database by restoring the production backup using RMAN and renaming the database to test. We've successfully restored and opened the database ...
8
votes
4answers
9k views

Why using innodb_file_per_table?

There are many articles exaggerating (IMHO of course) the need for innodb_file_per_table. I understand that with innodb_file_per_table, there should be a better control over the individual tables; ...
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2answers
3k views

How to deny drop permission for a table?

Is there a way to deny drop permissions for a specific table from a user or role?
2
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1answer
214 views

User Rights - Database Security

I am having following scenarios and i am having some issues and some questions. We have a DB Server on which we have some databases in these 2(two databases) are for my users. Now i have created 2 ...
5
votes
2answers
20k 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 ...
1
vote
1answer
378 views

Difference in between MySQL affected num rows and num rows

I am just newbie to the MySQL.I want to know what is the main differences in between mysql num rows and mysql affected num rows?Any example or references will be highly appreciable.
2
votes
1answer
275 views

How to recover SA account password without restoring it?

I forgot my SA password and resetting the password is out of the question because internal applications are using it and will will affect them. I also don't have an option to change the SA credentials ...
1
vote
1answer
404 views

How to get a unique highscore per user

I have the following tables: users, highscores I would like to get the top ten best results in highscore. The scores should be unique, meaning one score per user. I tried using INNER JOIN and GROUP ...
-1
votes
1answer
970 views

Difference in between HAS MANY and BELONGS TO in Yii framework [closed]

I am new to the Yii Framework. I discovered HAS MANY and BELONGS TO in the documentation, however I am confused about these features. Can someone give some real life examples with a diagram that ...
0
votes
1answer
545 views

Look for software that can convert sql (mysql) to erd

I would like to have an ER Diagarm in phpmyadmin, however, its graph is not up to my expectation, the graph has no relationship indicator (1-1) (1-m) etc at all. So i am wondering whether there is a ...
9
votes
2answers
1k views

Recovering logical space from a tablespace

I have a tablespace called DATA, and it is setup with auto-extend as false. This tablespace has two datafiles and is set up so it takes up 350 GB of physical space. A week ago I queried ...
5
votes
2answers
637 views

Running each SQL Server service under different Windows accounts

Besides the Database Engine, SQL Server has some additional Services, namely: SQL Server Integration Services SQL Server Analysis Services SQL Server Reporting Services SQL Server Agent Should ...
9
votes
2answers
1k views

100 TeraBytes Capacity Database - Resources and Time Estimates

I am working on a 'back of the envelope' calculation for a 100TB reporting database setup. I am seeking out thoughts from the experts here. Proposed environment: Storage Capacity ~ 100TB Tables ~ ...
-1
votes
2answers
1k views

Data Base Administration Oracle vs MySql? [closed]

I have worked with MSSQL for a while now, but now we want to try to move to some open source for a specific part of the company's products or explore Oracle if possible. What would you say are the ...
13
votes
2answers
59k views

oracle - list users with access to certain tables

I'm sure this has been asked before but I can't seem to find the relevant details for the following. Is there some sort of pre-built table that can do the following (I have used dba_tab_privs but it ...
10
votes
1answer
461 views

What does a SQL Server DBA need to know about Windows Server?

Analogous to my previous question What does a DBA have to know about SSAS?, which generated a really wonderful answer (thank you, @ConcernedOfTunbridgeWells!), I now ask a similiar question: What ...
21
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2answers
8k views

What does a DBA have to know about SSAS?

I've seen a lot of material covering the business aspect of SSAS, but not really much about the important aspects of administration and management. From the point of view of administering an instance ...
2
votes
1answer
121 views

MySQL switch between data directories for individual databases

I'm in the middle of designing a solution to an issue we're currently experiencing while writing to certain large MyISAM tables. The database in question basically stores information regarding two ...
1
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1answer
728 views

MySQL Cluster over WAN: Best Architecture Options?

My company is looking at a multi-data-centre solution for high-availability, fun, and profit. We have businesses across the planet, with the need for MySQL database clustering solutions that can keep ...
2
votes
1answer
386 views

How to prevent high memory, CPU and time consumption by MySQL restore?

I have a local test machine with 2 GB RAM and a dual core processor. I imported a dump on that using mysql -uuser -psecret < script.sql script.sql is a 700 MB file which contains a single ...
5
votes
2answers
405 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 ...
1
vote
1answer
214 views

Do you feel like DBA/DBD Is a “secure Field” still? [closed]

I noticed recently alot of Database jobs/Development have kind been pushed onto general developers, not to mention with NoSQL Solutions (Which IMO are probably a little easier for Non-DBA's to throw ...
3
votes
2answers
968 views

Problem with Czech collation Czech_CI_AI in MS SQL Server 2008 R2

I have the following issue with accent insensitive search in Czech language. My database is set to Czech_CI_AI collation. For some diacritics system works correctly (ie. I), but for some does not (ie. ...
3
votes
2answers
2k 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 ...
2
votes
2answers
638 views

How to compare performances of two databases

There are two database servers and I want to compare their performances. Both have Windows operating system and and Oracle (10.2.0.4 and 11.0.2) database. Both are OLAP databases with 15-20 users ...
1
vote
2answers
320 views

Is it good practice to assign a system account for database owner?

I can see the owners of my databases usign this query SELECT name , SUSER_SNAME(owner_sid) FROM sys.databases What are the things I should consider when choosing an account for database ...
7
votes
3answers
242 views

How do you protect against malicious PREPROCESSOR attacks in Oracle External Tables?

I'm a new DBA and I recently found out about the option of External Tables in Oracle using the PREPROCESSOR feature ( ...
19
votes
2answers
3k views

How to make a transition from SQL Server DBA to Oracle?

As an interest, if I would to transition from a SQL Server DBA to Oracle what will be the major learning or unlearning that I would have to do? I would assume the concepts are the same and the ...
2
votes
1answer
1k views

How to upgrade MySQL to a New version..?

I have installed mysql using the package management system.I am using ubuntu machine. After that i have very well configured the server for InnoDB and other server related parameters. I am using the ...
6
votes
1answer
166 views

On-the-fly query/command modification

I'm responsible for administrating an instance of SQL Server 200x which has the misfortune of serving as a backend to a turnkey application written with a disgusting performance problem. It repeatedly ...
3
votes
2answers
993 views

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 ...
2
votes
2answers
600 views

Generalisation in databases

I am working on a Hospital Management project in DB2. I have one table for staff with a primary key of staff_id. The hospital has to have different staff... e.g doctors,nurses,e.t.c. Is it better to ...
1
vote
0answers
203 views

Where does a DBA work? [closed]

I want to study for a DBA certification, maybe MySQL or Oracle 11g. I always have worked in small and medium companies. I wonder, in a big company like Google or Facebook, Where does a DBA work? in ...
2
votes
5answers
5k views

Small sample database for practicing database administration?

I'm looking for a portable sample database that can be created from a script has a simple ER model has little data for database administration practicing purposes. I know that there is e.g. ...
16
votes
1answer
19k views

What is the best way to reduce the size of ibdata in mysql?

I have some Production servers whose ibdata files increases in size day by day. It has already consumed 290GB of space. The tables in the servers are mostly InnoDB and there are high read and write ...
6
votes
2answers
3k views

Difference between Row based and statement based replication in Mysql?

What is the Actual difference between Row based and Statement based replication I actually looking in terms of replication effect's on slave. If I am using Row based replication then whats is the ...
3
votes
1answer
1k views

Master and Slave having same id's

I am working as a remote DBA for some of the production servers. There was replication from Master to Slave. There is something changed in the scenario they have made one of the Slaves as master ...
1
vote
1answer
899 views

Problem with MySQL Master/Slave reboot when in replication

There is a master and number of slaves connected to it. Due to some patches, we have to Reboot the Master and Slave. Afterwards, we have to make sure replication is running fine. While doing this ...
3
votes
1answer
1k views

Does `Seconds_Behind_Master` show exact Slave Lag from Master?

Does Seconds_Behind_Master show the correct result? I have also Implemented the mk-heartbeat replication monitoring. It was showing the other result in comparison with Seconds_Behind_Master. Which ...
3
votes
1answer
2k views

What memory should be given to the variables of my.cnf ?

Installing a MySQL server is quite easy. However, after installing, configuring the server is an important task for a DBA. Having 2GB of RAM and 250GB of disk space, how should I tune MySQL server so ...