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21
votes
3answers
5k views

How often to backup the master database?

The suggestion in BOL is fairly vague: Back up master as often as necessary to protect the data sufficiently for your business needs. We recommend a regular backup schedule, which you can ...
5
votes
2answers
6k views

How do I group results in batches of consecutive rows with the same 'module'

I'm looking for a seemingly very simple SELECT. I have a logging table LOGGING of which three columns are of interest to me: MODULE (text), PDATE (date), PTEXT (text). Actually, I care only about ...
5
votes
2answers
3k views

Estimate average and median efficiently in Postgres?

I have a Postgres database with tables in the billion scale. So any aggregate functions such as count() and avg(), as well as "order by random()" are very time consuming. Postgres has pg_catalog which ...
6
votes
2answers
7k views

Determine Reason for Deadlock in MySQL

We've been seeing some deadlocks occur but have not been able to reproduce. Is there any way to determine, after the fact, what queries were running, etc to figure out why deadlock occurred?
3
votes
1answer
2k views

MySQL InnoDB data file directly on a disk slice (fixed-size)?

It seems that ibdata1 is like a disk slice. In Solaris (UNIX) UFS filesystems (the common one before ZFS), one would separate their disk c0t0d0 into slices, say a 10GB drive would be cut into three ...
10
votes
2answers
11k views

Which performance counters can you look at on a SQL Server Instance to determine it's performance and over all health?

I am a student from Fontys University in Eindhoven, and I am currently carrying out a series of interviews to help with the development of a SQL Server tool and I would like to get feedback from the ...
2
votes
1answer
2k views

Installing MySQL server 4.1 on Ubuntu 11.04

how do I need to install mySQL server 4.1 on Ubuntu 11.04 server for a legacy app to run (it breaks on mySQL 5). sudo apt-get mysql-server-4.1 doesn't work - "package is missing, obsoleted or ...
1
vote
1answer
530 views

SQL Server sp_configure options?

Does anybody know where I can find a list of all the parameter options for sp_configure? It isn't really jumping out at me when I search online for possible variations and the capabilities of ...
8
votes
5answers
1k views

sql server concurrency performance

We have encountered some performance issue on our production environment. we found that when active sessions go up above 25, the usage of CPU reach to 100% and it takes long time to go down. The ...
0
votes
3answers
399 views

What all are the recoverable points of failure in an Oracle database?

I am testing a product against an Oracle database for failure scenarios. The product talks to Oracle through a session and maintains a few tables. I want to make sure that whenever Oracle recovers ...
1
vote
1answer
109 views

Can I install an additional oracle database on one node of an oracle cluster (RAC)?

Let's say I have a two-node Oracle RAC environment. Can I install an additional Oracle database on one of the node? Thanks.
3
votes
2answers
548 views

How can I model this relationship?

My database design skills are a bit rusty so I was hoping to get some help from y'all =) I have a 'user' table that contains all the typical fields (id,name,email,etc.). Users can have many '...
14
votes
4answers
853 views

Does NULL have a type?

Various sources (eg Wikipedia, PSOUG) state that Oracle's null does not have a type. Is this true? What about other RDBMSs?
4
votes
3answers
942 views

Improving slow queries. Slow query log attached

Below is the Slow Query Log when my .NET application was running. Please let me know how to improve the performance of the queries: TCP Port: 3306, Named Pipe: (null) Time Id Command ...
1
vote
1answer
639 views

Shift db data to another column

I have the following table id | ev_id | ev_loc_id | a | b | prev_a | prev_b If I the (ev_id AND ev_loc_id) not exist in the table then I just insert them, otherwise I'm putting the ...
1
vote
3answers
1k views

Please review the My.INI settings of my PC. File Attached

Below is the my.ini file of one of my PC running MySQL 5.5 with 1 GB RAM. It is not using concurrent connections and we are using a stand-alone PC for a single application and single user. # MySQL ...
3
votes
1answer
1k views

Duplicate UNIQUE KEY error after ROLLBACK in MySQL

I have a table like this mysql> describe seudonimos; +--------------+------------------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra ...
5
votes
2answers
10k views

Problem Reaching VM SQL Server Instance

Here's what I'm working with right now. I have a host OS which includes a SQL Server 2008 Enterprise instance. I have a virtual machine running on this host which has a SQL Server 2008 R2 Express ...
4
votes
1answer
5k views

Is it better to delete then insert, or to update then insert in SQL server?

I'm using SQL server 2005. I have a table that is basically a list of ids with timestamps that is recording the last time an event happened for that id. I have a list of ids in a table variable, and ...
1
vote
1answer
79 views

SQL query question

I want to find the records of August birthdays in own table.I'm using Datetime Field. Sample record: 01.08.2001 06.06.1985 26.08.1995 etc.. How should I do write a query? Regards,
8
votes
3answers
13k views

Optimizing InnoDB default settings

I looked into my.ini and saw various default settings. My database is running on a single stand-alone PC. I want to optimize the performance of InnoDB and MySQL in general for performance. There is no ...
1
vote
1answer
937 views

Ms Access queries equivalent in Sql Server

Queries in MS Access can act like views do in oracle in that you can query against them. Example: if you have a query in access called allProducts, you can also do SELECT * from allProducts; My ...
6
votes
2answers
2k views

Using IDs from multiple tables in a single column

One of my co-workers created a schema similar to the following. This is a simplified schema including only the parts necessary to address this question. The system rules are as follows: ...
8
votes
3answers
4k views

Wise to use trigger to update another table?

I have an Object table which is populated from an Integrated service (which I can change if needed) from another database. At certain points we need to manually add posts in another table ...
13
votes
2answers
29k views

Do INSERTs get auto-committed?

Our application fires an INSERT query to the MySQL Database to add records. I want to know whether or not the records get auto-committed. If I run the ROLLBACK command, when does the database perform ...
1
vote
1answer
330 views

MySQL Database Design Help?

I am going through my database and what I want to do is re-design it because I feel like it's very messy and that I am doing it wrong. This is just for practice; I've never had anyone teach me so I ...
5
votes
2answers
2k views

Database Hardware and Software to handle million requests per second?

I'm curious about the necessary hardware and software requirements to support a strong MMORPG. For example, what kind of requirement (both hardware and software) would I need if I were to build a ...
2
votes
1answer
1k views

Can't retrieve data of countries and regions

Goal: Improve my sql ability by doing some coding and reviewing existing code. Problem: I have spent lots of hour to find a solution based of this question "3c. Some countries have populations more ...
5
votes
2answers
3k views

Role db_ddladmin not working properly on SQL Server 2008

I want to allow certain user to create/modify objects on a database(tables, views, sp's, functions, schemas etc) and don't want to give db_owner. I thought I could do it with the db_ddladmin role, ...
1
vote
2answers
1k views

Are there any MySQL Triggers or Events that my program can wait for?

Say I want a live feed of emails on a web based email system. Emails are inserted into MySQL tables. Let's say I want my program to know immediately when the table is updated so it can check for new ...
3
votes
5answers
241 views

How can I store function names to be executed on a subset of rows?

I have a table, accounts, which contains the vast majority of the data I am concerned with. accountTypes contains different types of accounts (Business, Personal, etc.). I want to perform calculations ...
4
votes
2answers
387 views

SQL Server Version - are hotfixes for previous versions implied?

tl;dr: If I identify an SQL Server as having build X, and find out that X implies hotfix Y, does it also imply that all hotfixes listed for versions below X are installed? Or that only the hotfix for ...
2
votes
1answer
298 views

Are there other sites still using SQL Server with codepage 850 or codepage 437 for their sql scripts?

Using one of these codepages is a disaster when scripts are edited by Visual Studio or TFS, but sometimes it is difficult to change old standards. What must be observed, when changing to the current ...
8
votes
1answer
1k views

Can someone explain the magic of Opendatasource/Openrowset?

When pulling information from an excel file (or ms-access DB) I commonly use something like this: SELECT * FROM OPENDATASOURCE('Microsoft.ACE.OLEDB.12.0', 'Data Source=C:\test.xls;Extended ...
14
votes
1answer
10k views

How to migrate large blob table from mysql to postgresql?

I'm now in process of migrating my MySQL database to PostgreSQL. Almost everything went fine (well, after lots of googling for correct mysqldump params etc.) except one table I have - actually the ...
2
votes
2answers
1k views

Slow Query logging everything

I have a mysql instance that is logging slow queries. I have it set to 1 sec, but I am getting back lots of these:(example) Query_time: 0.000237 Lock_time: 0.000064 Rows_sent: 0 Rows_examined: ...
4
votes
2answers
1k views

Index Generation in Postgres

We have a database with a single table made up of around 700 million entries. We update the database by adding new entries on a server then transfer the server to the production server using pg_dump: ...
5
votes
3answers
2k views

How can I find the VLF count for a SQL 2005 database without running dbcc loginfo?

Is it possible to find the number of VLFs in a database's transaction log without running DBCC LOGINFO? DBCC LOGINFO seems a little heavy and verbose when count is the only information my t-sql script ...
15
votes
2answers
6k views

What are the benefits of using MySQL Cluster?

I have never dipped my hands in MySQL Cluster and want to know how it can benefit me. When is it best to use it, and does it have performance benefits?
0
votes
2answers
3k views

Possible career paths for Oracle Certified Associate (OCA) [closed]

In order to be confident in databases as a entry level job candidate, I completed the OCA certification. Now I want to know what career paths follow this. Can one go into data-mining, BI, or R&...
3
votes
2answers
139 views

What would be the best way to model my simple table?

What would be faster: searching for the right row through a table with 17 different columns, each with a tinyint value of 1-4? Or, searching for the right row through a table with only 1 column with ...
3
votes
1answer
5k views

What is the corresponding MySQL TimeStamp in MS SQL Server?

I need a timestamp to be created automatically when I insert information in a table. mySQL has TimeStamp but MS SQL Server TimeStamp doesn’t correspond mySQL. Is there any other way around?
25
votes
4answers
13k views

Whether or not to create separate tables for different product types?

I'm in the process of designing a database and I'm having second thoughts about my initial design decisions... Product types are as follows... Models, parts, replacement part kits and options. ...
6
votes
3answers
26k views

When creating views, why do users need direct object permissions if they already have the same permissions via a role?

I'm having a problem with permissions in Oracle 10g. I'm hoping someone can help me make sense of this. I have a schema with a table in it. I have granted select on that table to a role. grant ...
3
votes
1answer
2k views

Simplest way to constrain an SSIS Execute Process Task

We have some complex SSIS packages, currently in SSIS 2005, that use Execute Process Task in order to call out to do some business logic. Some of these called programs are not as stable as one could ...
4
votes
1answer
459 views

Proper Database Partitioning

I had asked a previous question "Proper technique for storing users event data" and the correct answer in my opinion was to create a database partition. Now from what I have read on it there are ...
3
votes
2answers
3k views

Is it possible with SQL Server 2008 to have a Partioned Tables with an Identity Column?

I'm not thinking of using it for the partition function. I just want to know, if it is supported or not. Don't tell me why it is not a good idea to use such columns on partitioned tables.
2
votes
1answer
511 views

SQL Server Logon Trigger causing problems with the Distributed Transaction Coordinator

I've created the following simple logon trigger on my SQL Server 2005: CREATE TRIGGER LOGON_RESTRICTION ON ALL SERVER FOR LOGON AS BEGIN PRINT 'Hello World' END GO Which seems to be working fine ...
3
votes
2answers
2k views

Piplelined Result Set over Database Link Alternatives

Since a pipelined result set cannot be returned over a database link (see MOS note 560743.1), what workarounds/alternatives are there. I can think of a few, but I'd rather not lead the question. I ...
4
votes
3answers
562 views

Database Schema with a shared identity Field

I'm a developer treading into the database world so bear with me please. I'm creating a Contract database with separate tables for various types of contracts. I have 5 tables but would like to ...

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