3
votes
3answers
15k views

Where does my.cnf get stored in Linux?

I am new to linux, and i just installed MySQL-server-5.1.59-1.glibc23.i386.rpm in my linux machine. I wanted to know where my.cnf file gets stored..? Will my.cnf gets created with the installation ...
1
vote
1answer
373 views

Precomputing expensive aggregations

I'm looking for a tool that will let me precompute expensive aggregations some time after rows have been inserted into a MySQL database. For example, if I often run a SUM() on a column, I'd like to ...
11
votes
3answers
8k views

What is the default order of records for a SELECT statement in MySQL?

Suppose you have the following table and data: create table t(k int, v int,index k(k)) engine=memory; insert into t values(10, 1), (10, 2), (10, 3); When issuing select * from t where k = 10 with ...
1
vote
2answers
1k views

why does my pivot give me an error?

Msg 207, Level 16, State 1, Line 1 Invalid column name 'FullName'. select FullName, ['1-Urgent'], ['2-High'], ['3-Medium (3000)'] from (select FullName,AltBusinessSeverity, total from Mdata) AS ST ...
6
votes
2answers
3k views

How can I improve my SQL statement with weekly results with week starting on Thursday or any other day of the week?

I am a total newb, and I couldn't find a good way to do this anywhere. I have a database table that contains statistics that are recorded at various time throughout the week. The reporting week ...
6
votes
2answers
1k views

Single data type for imprecise date values, as allowed by ISO 8601

How can I store date and time values with reduced precision in a PostgreSQL type, and have them behave as date and/or time values? ISO 8601 allows date values with reduced precision. ‘1964’, ...
1
vote
1answer
645 views

How can I get the maxium number of concurrent connections to MySQL over a specific time interval?

I have a monitoring app that checks MySQL's Threads_connected and Max_used_connections variables every X seconds. Neither of these variables tells me what I want to know: The highest number of ...
3
votes
1answer
162 views

Extreme storage beasts

Intro I have derived this question from my previous question Single Drive vs Multiple Drives After getting a very detailed answer from a very helpful member RolandoMySQLDBA and learning the fact that ...
6
votes
2answers
1k views

Single Drive vs Multiple Drives

Generally bottleneck of RDBMS (I am a MySQL user) performance is disk access. SSD provides great performance compared with conventional spindle drives. Question : Is it possible to improve ...
2
votes
1answer
2k views

Error restoring SQL differential database files

Occasionally I'm having problems restoring DB differentials. I'm getting the error "the differential backup cannot be restored because the database has not been restored to correct earlier state." ...
14
votes
4answers
31k views

How do you kick users out of a SQL Server 2008 database?

We need to do a restore, and cannot because other users are connected. We thought we had disconnected every process, but apparently not. How can we, from Management Studio, kick off everyone else so ...
2
votes
3answers
7k views

Return int value from boolean field in SQL select

Is there a way to return an int value for a boolean field in a sql select statement?
3
votes
3answers
785 views

Converting CHAR to BIT

I have a column with char(16) data type and it was mistakenly set to char(16) actually it should be bit(1) because it contains only three distinct values as follows: 16 characters long string 10 ...
4
votes
3answers
19k 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
1answer
922 views

Table Variables - Scope Error - Must declare the variable 'X'

This is my first post and not sure how to fix this auto format draft? Using SQL Server 2000. The table variable that is giving me this one error is '@SBLH' The following is the multi-select function ...
3
votes
1answer
572 views

Oracle RAC can you have a cluster that contains one node

Have oracle RAC production system. Two nodes in the primary, two nodes in the secondary. Getting a test system.Can we have two nodes in the primary and one in the secondary? Or to put it another way ...
1
vote
3answers
311 views

Compare content of databases in Oracle

we have a request to build an ASP.Net application that will be used as interface to launch commands on Oracle databases. We need to find a way to compare the content of 2 databases. We prefer not to ...
2
votes
1answer
513 views

SQL Server 2008 Mirroring Pauses without warning

I have several databases mirroring with a witness. All 3 machines are local to our network and have generous nics. Monitoring the mirroring, it does not seem like there is a lot of network traffic. ...
4
votes
2answers
1k views

Trying to get multiple mysql instances running on Ubuntu dev box

I'm trying to get multiple instances of mysql running on a dev box for some testing. This guy is running ubuntu so the setup's a little different than our production setups. I'd like to find the ...
4
votes
2answers
552 views

Learning Oracle, does it matter if I install 10g or 11g?

I'm taking a class in Databases, they're using Oracle 10g in class, but I'm having some trouble installing the database here in Windows 8 (auth problems), so I thought I'd attempt 11g. Is 11g ...
15
votes
4answers
1k views

Is table aliasing a bad practice?

I remember learning to do this in a DBMS course for Master of Information Services students. To save yourself some typing, you can type: SELECT t1.id, t2.stuff FROM someTable t1 ...
1
vote
3answers
2k views

Grouping results to get unique rows after multiple joins

this is my first question on dba.stackexchange, hopefully it will be worth it. I am usually a bit more active on Stackoverflow as I am a developer. disclaimer : I don't have full control over the db ...
0
votes
1answer
109 views

How should I model this data?

I have a need to model the following requirement for a web application (PHP/MySQL5): A user can compete in a distance-based challenge which consists of entering progress along a defined ...
3
votes
1answer
6k views

How to query given grants on Oracle?

On a database I had to execute the following two statements: GRANT CREATE ANY TABLE TO MyUSER; GRANT DROP ANY TABLE TO MyUSER; What I miss is the query which tells me that those grants are given. I ...
7
votes
3answers
7k views

Best of MyISAM and InnoDB

Is it possible to make InnoDB to use indexes same as MyISAM instead of clustered index due to limitation of RAM while getting benefit of its concurrency performance?
3
votes
2answers
183 views

What are the best Database Analytics Companies for analyzing several 1000s or Mio. of products,sum them together and analyze them for statistics?

We will get several thousands products in our database. The problem is that one product can have several different names e.g. "iPad 16GByte UMTS schwarz" or "iPad 16GB 3G black" and so on. But they ...
3
votes
2answers
2k views

SQL Server 2008 R2 - Error 18456 State 12 - nothing I find helps me

First off let me state that I'm not a DBA, I don't have access to a DBA, I'm just a programmer who has to get a CMS working. I'm generally pretty good at getting random servers working, but this is ...
1
vote
1answer
378 views

Is it possible to fetch or update table data by table field type?

Is it possible to fetch or update table data by field type? If possible please tell me with a sample code.
1
vote
1answer
1k views

About “pg_ctl promote” of PostgreSQL9.1

Today I test the new feature about "replication features" of PostgreSQL9.1, First I have installed the Hot-standby of PostgreSQL9.1 successfully. It is not a problem。 What I want to test is that I ...
1
vote
2answers
284 views

Table partitioning

Recently I have been looking to optimize my database and its size is 7GB. I have an option to partition big table. But partitioning would just divide the big table into small ones while remaining on ...
1
vote
1answer
143 views

Migrating or Synchronizing SSAS Changes

Assume you have 2 SSAS databases, DB1 and DB2, that are identical. Now they branch off. Changes A and B are made to DB1 and changes C and D are made to DB2. Is there an easy method to migrate ...
2
votes
1answer
1k views

Export data into word documents

My boss has a kindle and likes to save a lot of stuff to his clippings. Currently I'm going through and cutting out each clipping and pasting it into a seperate word document with the title of the ...
4
votes
2answers
2k views

Database design for dynamic Meta fields of an entity that shall be queried intensively

I'm designing a database structure for a system at which an entity can have a dynamic set of user-defined meta attributes. The meta fields (e.g.: popularity, conversion etc.) and skill values (int, ...
1
vote
2answers
902 views

MySQL: How does AES_ENCRYPT turn the password into a key?

I am trying to figure out how to create the best secure password for AES_ENCRYPT. Specifically, how long should the password be, and how it translates into the 128 bit key length that AES typically ...
54
votes
8answers
4k views

Does SQL Server read all of a COALESCE function even if the first argument is not NULL?

I'm using a T-SQL COALESCE function where the first argument will not be null on about 95% of the times it is ran. If the first argument is NULL, the second argument is quite a lengthy process: ...
2
votes
2answers
9k views

How to replace a CLOB column by a varchar2(4000) column?

The following code seems to do the job, but I doubt, that it is robust enough. SET serveroutput on DECLARE v_isclob PLS_INTEGER; v_cmd VARCHAR2(4000); BEGIN SELECT CASE when exists ...
3
votes
3answers
539 views

Dynamically changeable database

We have a database and some data is stored in a Trucrypt folder, my question is how can I include this trucrypt folder. The data type is MyISAM. I saw there is a symbolic link, but not really clear ...
1
vote
1answer
352 views

If archiving is disabled and the last redo log file is full, why LGWR continues by overwriting the first available active file, not inactive file?

I found the following sentence from Oracle documentation. If archiving is disabled (the database is in NOARCHIVELOG mode), then when the last redo log file is full, LGWR continues by overwriting ...
2
votes
1answer
232 views

Does 'LGWR' writes to online redo log files strictly in circular fashion?

Does 'LGWR' writes to online redo log files strictly in circular fashion? I saw this sentence from Oracle documentation. If archiving is disabled (the database is in NOARCHIVELOG mode), then when ...
16
votes
2answers
29k views

Multi cores and MySQL Performance

Importance of RAM is an established fact but far less material is available about the importance of cores and multithreading when it comes to the usage of CPU by MySQL. I am talking about the ...
4
votes
2answers
3k views

How to convert mysql database charset to utf-8

I have a vb forum with a huge amount of data I need a way to convert this forum database tables charset with thier data from latin1_swedish_ci to utf8-general-ci How to do this ?
2
votes
2answers
4k views

Attach SQL Server 2008 R2 on SQL Server Express 2008

I have a database on SQL Server 2008 R2. I want to attach it on a SQL Server Express 2008 instance running on Windows 2003. I set the SQL server compatibility level on the database to SQL Server ...
4
votes
3answers
373 views

sql script repository [closed]

I am a fresh DBA just being promoted, I am looking for few good sites which constains T-sql Scripts for DBA tasks. Is there a common place from where you can get a collection scripts to perform ...
1
vote
1answer
452 views

How to restore a database from a newer version of SQL Server

I have SQL Server 2008 and I want to restore a database from SQL Server 2008 R2. When I try to restore, SQL Server produces an error message that the database came from a newer version of SQL Server ...
3
votes
2answers
369 views

Unable to BackUp Database on SQL2005

I have a database in MS SQL2005 that I can not backup. Whenever I try to create a backup of the selected database through SQL Mgm studio I get this error: The Backup of full-text catalog in not ...
2
votes
1answer
142 views

Oracle Backup and Recovery Issue

I have backed up database located on Host1 and restored/recovered it on Host2. After a while, I backed up DB on Host1 again. Now I want DBs on Host1 and Host2 be the same using last backup. How can ...
4
votes
1answer
477 views

Why is 'Allow Snapshot Isolation' set to TRUE on the master and msdb databases?

Why is the database property Allow Snapshot Isolation set to TRUE on the master and msdb databases, but FALSE on other system databases? The default option for this property is also FALSE when ...
0
votes
1answer
2k views

SQL keyword difference between MySQL and Oracle 10g?

Good afternoon, Are there differences between Oracle 10g and MySQL with the CREATE, ALTER, DROP, REF, PRIMARY KEY, FOREGIN KEY and attribute variable type keywords? The reason I ask, is I'm planning ...
7
votes
5answers
7k views

How do I copy my SQL Azure database to a local SQL Server instance?

I have an OLTP database hosted on a SQL Azure instance. I want to pull a copy of the database down from the cloud so I can run some heavy extracts and OLAP-style queries against it without impacting ...
2
votes
2answers
4k views

getting error installing oracle 11gR2: cannot access node

I'm installing Oracle 11.2 on dedicated hosted server (centOS 5.5). I've gone through the Oracle Quick Installation guide diligently. I believe I've set everything up correctly, although I'm not a DBA ...

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