The discipline of Operational and Architectural Management of Database Systems.

learn more… | top users | synonyms

15
votes
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 ...
9
votes
2answers
2k 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
vote
1answer
673 views

Create database on new partition

I use postgresql 9.1, on ubuntu 12.04. I had installed the depot package. I have added a new partition to my system, and I would like to create a postgresql database on this partition ( which will be ...
2
votes
3answers
772 views

Database Design Relationship for Patient Visit in MS Access

I am designing a database to store records for research purposes, and I am having trouble picturing how I can create a relational database based on the information I have. There are a total of 6 ...
6
votes
1answer
159 views

What is a good way to determine the performance I should expect from a PostgreSQL server?

Trying to figure out how I should expect my database to perform. Basically, I need to determine when the server I have set up is reaching its performance limits - which would help me plan server ...
4
votes
1answer
167 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 ...
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; ...
5
votes
2answers
494 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 ...
2
votes
0answers
350 views

How to properly configure pgBouncer transaction level pooling?

What is a good way to determine the number of available transaction connections when using pgBouncer to pool database connections? Also, how should I determine the number of max_connections and ...
2
votes
2answers
2k views

Cannot login to Oracle11g with System username

I just installed Oracle 11g into my machine. I was about to shut down a database instance, and Oracle asked me for username and password, I provided the credentials I used to login into the web ...
6
votes
2answers
846 views

Two corrupted indexes found by DBCC CheckTable

I'm wondering if this problem is solvable by dropping/recreating the two indexes. Both are rarely used, nonclustered, non PK, non FK indexes. Here is the dbcc output: Table error: table ...
13
votes
2answers
62k 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 ...
0
votes
1answer
158 views

What is the maximum number of rows in a clustered index on datetime column?

I would like know what the max no of rows is in a clustered index (non-unique) on a datetime column table in SQL Server 2008R2.
1
vote
2answers
201 views

Database Is In InRecovery Mode.

I have a database that has entered "Recovery Mode". It was working fine, but ended up in this status a few days ago. I have been told that a cause can be the partition holding the datafiles running ...
3
votes
1answer
13k views

What queries is Oracle executing, how frequently, and time-taken?

I have a (Java) web-application, that of course executes many queries (selects, inserts, updates, deletes) to the Oracle Database. I want to find out the following for last 7 days: SQLQuery ...
2
votes
1answer
543 views

How to grant permission for am administrator account in SQL Server 2012? [closed]

I installed SQL Server 2012 on my laptop. I am trying to run a script to create a simple database. SQL Server version: 11.0.3128 SSMS starting parameters: server type: database engine server name: ...
4
votes
2answers
1k views

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 ...
4
votes
3answers
17k 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 ...
2
votes
3answers
4k views

Detecting SQL Server Utilization with a query

My current project will send queries to an sql server constantly and It may use 100% of the memory or CPU. How can I check if the server is nearing full utilization in a stored procedure so that I ...
0
votes
2answers
360 views

Remote database connection problem?

I have two systems with Windows XP. I have installed SQL Server 2005 on a system and tried to use SQL Server Management Studio Express on both to use the database. I am able to use the database on ...
0
votes
1answer
1k views

mysql fine tuning: open_tables, opened_tables

I'm a novice to database administration and have been depending on forum suggestions and answers to help resolve my database hang ups and too many connections errors; I've managed to reduce the ...
1
vote
1answer
634 views

MySQL Tables crashing randomly

This is one of the many random Tables that get corrupted. Any ideas why and what would be causing this? How do I keep MySQL tables from crashing and MySQL from crashing? Repairing USR_wp537 ...
9
votes
3answers
248 views

How to tackle a large undocumented database

I recently got hired as the only IT Guy in a certain Company X and I am tasked to fix their applications, and in my opinion, the best way to start is by understanding the database. Their current ...
2
votes
1answer
1k views

Mysql - show results from 3 tables excluding NULL or EMPTY values for certain fields

I have 3 simple tables with polls, users and votes. I'd like to show all polls ordered by clean count of votes (sometimes either poll_id or user_id don't get inserted). Furthermore I'd like to show ...
2
votes
1answer
1k views

Solve conflict between affinity mask and I/O affinity mask?

I executed this on one of our SQL Server machines: EXEC sp_configure 'show advanced options', 1 And then executed RECONFIGURE. This presented me with the following error message: The affinity ...
2
votes
1answer
166 views

How can I rename a table, but also all FK etc. references to that table?

I would like to e.g. rename my Applicant table to ApplicantProfile, as applicant is an abstract entity that has a profile. The profile is not the applicant. Simply renaming the table is hopelessly ...
1
vote
2answers
1k views

How to identify the db orphan mdf and ldf files

I want to identify the orphan mdf and ldf files on the disk and remove them. After searching on the internet, found the script below on MSDN forum. But when I run the script it returns many ...
3
votes
2answers
568 views

Perl vs Ksh for Unix Database Administration

I realize this is a somewhat more subjective question, but I am looking to the community for guidance. Our company is fairly new to having DBAs. We used to use DB2 for i on the IBM's iSeries servers, ...
2
votes
2answers
391 views

How to login in database if we have lost password? [duplicate]

Possible Duplicate: gain admin access to sql express 2008 Is there any idea if we lost our password to login in database using sql express management studio? Is there any place where ...
1
vote
1answer
1k views

listener does not currently know of SID given in connect descriptor in oracle 10g and solaris 10 env

I have a oracle 10g database in solaris 10 system. The SID=OTRS, I can connect to oracle database from local server itself. But I can not able connect from another client. It is returning an error ...
0
votes
1answer
66 views

PostgresSQL: Cannot get to console under different user name

I normally get to the console in UBUNTU by typing: sudo -u postgres psql But I need to delete a database owned by a different user. When I type: sudo -u username psql It tells me "database ...
2
votes
1answer
2k views

Is there a progress indicator for OPTIMIZE TABLE progress?

MySQL 5.1.4x (Windows) | Innodb I recently purged data from a mySQL DB (a few hundred thousand rows) and I'm planning to use OPTIMIZE TABLE LOGTABLEFOO1,LOGTABLEFOO2,LOGTABLEFOO3; to reduce the ...
5
votes
1answer
450 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 ...
5
votes
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. ...
1
vote
0answers
176 views

Database instance keeps restarting

From the past few days, our MySQL database instance has crashed and had to be restarted a few times. My MySQL version is 5.1.57-log. The CPU and memory usage was way below 50% during the crash time. I ...
2
votes
2answers
251 views

Database structure for a system with multisite

The system I'm working is structured as below. Given that I'm planning to use Joomla as the base. a(www.a.com),b(www.b.com),c(www.c.com) are search portals which allows user to to search for ...
0
votes
0answers
1k views

Achieve log transfer to standby (Data Guard)

I am not able to transfer my archive logs from primary to standby. I executed the following query: archive log list Database log mode Archive ...
4
votes
2answers
548 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 ...
-4
votes
1answer
107 views

Advice for designing a complex/multipart application [closed]

I'm designing a software application for my medical carrier. It is very complicated, with many parts and many small details. Some experts advised me to divide it to parts, then design the database ...
1
vote
1answer
3k views

DBF file exist while user has been dropped?

I am new to Oracle. I have dropped some users from my database using: DROP USER username cascade; The issue is that the .dbf file still exists in the $ORACLE_HOME/dbs/oradata/ directory, which is ...
6
votes
1answer
3k views

Moving postgresql data to different drive

I am using AWS as my cloud environment. I installed PostgreSQL on the same drive as my root instance volume. I have attached and mounted the second drive to my instance. Now I want to move all my ...
4
votes
1answer
361 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?
1
vote
1answer
299 views

mysql session logging tables

I've been building a session logging system for our sites. We get around ~15m hits a year and at the moment we're really only interested in stats about people who logon to our sites. Our table ...
1
vote
1answer
137 views

a question in tables relations

Table A is linked to Table B , and Table B is linked to Table C using primary and foreign keys My questions: Should i link Table A to Table C too?? Or Table B can act as intermediate link between ...
0
votes
2answers
87 views

what is the best choice from those two tables?

what is the best choice from those tables?? table A : keep DB simple with lower number of tables ... but i will find difficulties if i wanted to extract certain data from column of doses coz it's ...
2
votes
1answer
1k views

Recover database until cancel without prompt?

The statement: RECOVER DATABASE UNTIL CANCEL prompts once to select the archive log file. Is there a way to pre specify the value so as to be able to use it in a script without prompt? I have ...
19
votes
7answers
28k views

How can I tell if a SQL Server database is still being used?

We're looking to decommission a SQL Server instance which has a couple databases still remaining on it. How can I tell if they are still being used by users or a web application? I found a forum ...
1
vote
1answer
128 views

Regularly import tab-seperated log file to MySQL

I'm looking to keep arpwatch entries in a MySQL database to crossreference with other information I'm storing based on mac addresses. I've manually imported the arpwatch database into my mysql ...
3
votes
3answers
168 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 ...
0
votes
3answers
268 views

How do I enable READ-only (passive) mode in a particular RDBMS?

As most of you have noticed all StackExchange sites have been under maintenance/recovery a few days ago so they switched on READ-only mode. From their blog I know they used to use MS SQL Server 2008, ...