6
votes
1answer
11k views

What makes an Oracle Applications DBA different from an Oracle DBA?

All Oracle databases support some type of application that the Oracle DBA would need to have some knowledge of. What makes an Oracle Applications DBA different than this? Does the term mean that ...
2
votes
1answer
132 views

Does document “depth” affect CouchDB performance?

I have a project where it is very tempting to use a deeply nested collection of data. But how does that affect performance? Are there any reasons why I should avoid doing this? I'm talking about lists ...
1
vote
3answers
213 views

PostgreSQL: 8.3/8.4 interface chages?

I would like to upgrade a PostgreSQL 8.3 server to PostrgreSQL 8.4. There are many software components that interact with the server over the network, and I am concerned with compatibility issues. Is ...
9
votes
3answers
312 views

Query Performance Tuning

When you finish writing a query/stored proc/function, what's the most informative way to quickly get some performance parameters? Do you run the query and view the actual execution plan? If so, what ...
9
votes
3answers
2k views

MySQL High Performance for Lots of SELECTs/INSERTs/UPDATEs/DELETEs

I am creating a module where every user often gets a record into a table for 10 to 300 seconds. When the time expires a record gets deleted. The case is: there will be a lot of users and records will ...
2
votes
1answer
225 views

Where to put glogon.sql in 32-bit ODAC (11.2.0.2.1)?

I installed the 32-bit ODAC (11.2.0.2.1) from here. The Oracle Universal Installer version contains Oracle SQL*Plus 11.2.0.2.0. But I'm missing the sqlplus/admin/ folder in the installation, where I ...
7
votes
2answers
353 views

Is there any way to efficiently perform the equivalent of DENSE_RANK in MongoDB?

SQL Server and Oracle both have DENSE_RANK functions. Is there a way to do something similar in MongoDB without having to resort to MapReduce? In other words, suppose you have a T-SQL select clause ...
1
vote
4answers
282 views

Is there a DBMS that allows the “= NULL” syntax?

Inspired by a StackOverflow question (Why doesn't SQL support "= null" instead of "is null"?). Is there a DBMS that actually supports the = NULL syntax?
3
votes
2answers
1k views

xp_sendmail: failed with mail error 0x80004005

when I run xp_sendmail exec master.dbo.xp_sendmail @recipients='me@hotmail.com', @subject='terrrible thing happened', @message='test'` I am getting an error Msg 18025, Level 16, State 1, ...
7
votes
4answers
1k views

SQL Server: what should be done when a process is blocking another process?

I'm an accidental DBA and still learning. When I see from DMV:s or Activity Monitor that some process is blocking another process, what should be done? Should I simply kill those processes or is ...
11
votes
6answers
3k views

SQL Server Checklists

Following up from my other question, I would like to start thinking about what I should take a look at on daily/weekly/monthly bases in terms of alerts. I am hoping to be able to see problems coming ...
2
votes
1answer
278 views

Health checking via Database Mail in SQL Server

I have a few Sql Scripts that I would like to run every day on my Sql Server(s). How can I query multiple times and have the output similar to the following: Health check for <server> Query ...
24
votes
13answers
7k views

How to implement a 'default' flag that can only be set on a single row

For example, with a table similar to this: create table foo(bar int identity, chk char(1) check (chk in('Y', 'N'))); It doesn't matter if the flag is implemented as a char(1), a bit or whatever. I ...
10
votes
4answers
3k views

What tools are there to generate test data for SQL Server?

As you can see from another question of mine, generating test data is my theme right now. At this point, I'm still generating my test data by hand. However, this process always generates small ...
5
votes
2answers
7k views

Best Book to Learn MySQL [closed]

I would like to read a book about MySQL database with emphasis on performance and optimization on Linux server. I appreciate your suggestions.
2
votes
3answers
306 views

Non-deterministic aggregated result

Why is my query non-deterministic? I have query that do the following: select sum(float1*float2*coalesce(float3,1)) from table When I run this query I get a deterministic result, but it seems not ...
2
votes
3answers
3k views

Pros and Cons of SQL Server Database Mail

I'm planning to use SQL Server Database Mail. I'll have a table where mail receiver details and mail content is stored and I want to schedule this mailer (every minute) to send mails to the new ...
4
votes
1answer
790 views

SELECT INTO creates a new table?

I have an original table MessageQueue with six columns. When I try to do a SELECT INTO that table it creates a new (local) table called <network domain\user name>.MessageQueue with only three ...
5
votes
2answers
165 views

Database placement on abstract storage structure

Often times we all hear the same thing. The recommendations on where to put OLAP/OLTP databases, where to put the tempdb, where to put transaction logs...etc. But say you are in an environment where ...
6
votes
2answers
2k views

SQL Profiler - Scripting a trace with HostName filter

I have a stock of scripted trace definitions that I use for different levels of diagnostics, none of which filter by HostName. I needed to filter traffic by host today so: Fired up Profiler Created ...
14
votes
5answers
7k views

How do I force one record to have a true value for a boolean column, and all others a false value?

I want to enforce that only one record in a table is considered the "default" value for other queries or views that might access that table. Basically, I want to guarantee that this query will always ...
4
votes
0answers
166 views

Which SQL datatypes exist since when and in which RDBMS? [closed]

I found a general comparision of different SQL implementations that only covers some data types (BOOLEAN and TIMESTAMP) and a comparision of datat type support in different RDBMS from 2009 that does ...
5
votes
5answers
851 views

Advice with date column SQL Server 2005

I have two datetime columns in SQL Server 2005 that I need to query without the time portion of the datetime. Currently, my query looks something resembling this (just an example): WITH Dates AS ( ...
8
votes
3answers
22k views

How to solve UTF8 invalid byte sequence copy errors on a restore, when the source database is encoded in UTF8?

I was given the task to migrate a PostgreSQL 8.2.x database to another server. To do this I'm using the pgAdmin 1.12.2 (on Ubuntu 11.04 by the way) and using the Backup and Restore using the ...
4
votes
1answer
733 views

How to get text for default language

I have so tables: and so data at Language table: and so data at Text table: I have to return text for requested language if it exists and text for default language if it does not exist. Is it ...
2
votes
1answer
2k views

Does msmdpump.dll pass the authentication info to SSAS?

I'm using msmdpump.dll with basic authentication to access a SSAS OLAP cube from the internet. Does this method pass the auth info to SSAS so if I put permissions on the cube they get applied ...
2
votes
2answers
200 views

Extract specific backupfiles from SQL Server 2008 backup

I have a big .bak file containing a full backup and some transaction log backups. Is it possible to extract only the transaction log backups so I can copy them to another PC? (the full backup has ...
10
votes
2answers
6k views

What is blocking and how does it happen?

I tried to find some information about blocking in SQL Server, but I could not find a concise explanation for what it is and how it happens. Could you please enlighten me?
8
votes
1answer
616 views

Generating large strings for test data

I was recently trying to create some large strings containing generic test data for a question here. It seems that I used to know of a way to multiply a string. However, I can no longer remember the ...
4
votes
1answer
1k views

PostgreSQL: Corrupt primary key, inconsistent table

While recovering from a cloud failure, I found that some tables on a PostgreSQL database are behaving strangely. These tables are indexed using a primary key, but a pg_dump yielded duplicate fields, ...
11
votes
2answers
1k views

SQL Server: Has anyone used the large-page allocations tuning option?

Has anyone used the tuning option of using TF834 large page allocations. I was just reading an MS article on it and was wondering if anybody had used it and seen performance gains. Are there any ...
4
votes
3answers
361 views

Database Design Issues

My question consists of three parts: When can I be sure that my database design is perfect? Is returning to the database design to change some issues (i.e, adding new column, deleting a column, ...
6
votes
2answers
2k views

powershell to get sql server memory counters and show value

I am writing a powershell script to capture the following SQL server counters: SQL Server: Memory Manager: Total Server Memory (KB) SQL Server: Memory Manager: Target Server Memory (KB) My ...
4
votes
2answers
1k views

SQL Server query result transfer time over VPN (WAN)

I have a mysterious phenomenon on one remote SQL Server 2005 which I manage and query using SQL Server Management Studio. I connect to the server through a VPN tunnel (provided by an ISP, about 8 ...
5
votes
3answers
689 views

Why is Row Overflow not working on SQL Server 2005

I have a SQL Server 2005 database with a table that has around 860 columns. Aside from the ID column all other columns are varchar(N) where N is either 100 or 500. Upon inserting a new row (via an ...
9
votes
2answers
5k views

How can I have SQL Server email me the error details when a job fails?

SQL Server lets you configure a job to send email alerts when it fails. This is a simple and effective way to monitor your jobs. However, these alerts do not include any detail--just a success or ...
5
votes
2answers
1k views

Oracle clean up

I have an Oracle database on a VMWare image that seems to be slowly eating all my available disk space. I would like to know if there is a command or script that would perform some kind of clean up of ...
14
votes
7answers
330 views

Which of these table designs is better for performance?

I have been asked to create something which tracks the daily cost to collect on accounts, and I am trying to figure out a database table schema that would support this. Here's what I know Company ...
4
votes
2answers
2k views

PostgreSQL: Using schema and table names from other tables?

Consider the situation where I have all my schema names in one table and all my table names in another table. Is it possible to do something like in the following? SELECT value FROM (SELECT ...
4
votes
2answers
129 views

Performance of SQL Server indexing

I want to see the performance differences between an indexed vs non-indexed column when running the same query. The table I've created (FileCollection) is very simple and has the following 3 columns ...
2
votes
4answers
5k views

How check that Oracle Database is Up?

For our application we have configuration file for connection to the Oracle Databese (url, user, pass). Application start for 2-5 minutes. If some wrong with databese i see this in logs, but i must ...
6
votes
3answers
4k views

Too Many Connections

I'm using MATLAB to feed the database but after a time I'm getting a too many connections error. I always using opendb and closedb in pair. Is it to fast the feeding? Do I have to wait after I ...
3
votes
1answer
694 views

SQL Server Embedded Edition vs SQLite

Can anybody shed some light on how these SQL products compare? No need for essays, only highlights such as "X supports this, while Y doesn't". How is efficiency affected as the database grows ...
3
votes
1answer
1k views

Getting error on SQL Server

I am getting these error messages one after the other every week on Win 2008 and SQL 2008 R2. MAX DOP is set at 1. Any idea how I can solve this? Thanks. DESCRIPTION: A fatal error occurred ...
3
votes
1answer
455 views

sysarticles system view - what does a status of 57 mean?

I'm trying to work out why one article within a publication isn't replicating. I've scripted it out and confirmed the replication procs it's supposed to call are the correct ones, and have run a trace ...
20
votes
3answers
4k views

Efficency of stored procedures vs raw queries

I have read much on both sides of this debate: is there a signficant performance gain to be had by using only stored procedures over raw queries? I am specifically interested in SQL Server but would ...
6
votes
2answers
292 views

How can I secure my database code?

We have a lot of proprietary database code that is simply encrypted using the "WITH ENCRYPTION" option. Unfortunately, this is a very weak method of securing database code. Is there any better way ...
16
votes
3answers
5k views

Why is `SELECT @@IDENTITY` returning a decimal?

I'm using Dapper to execute the following query against a SQL Server 2008 R2 Express instance from a ASP.NET MVC 3 (.NET 4.0) application. INSERT INTO Customers ( Type, Name, Address, ...
11
votes
2answers
148 views

A question on SARGability

I just need to confirm that I understand something correctly: I recently viewed an SO question in which a user posted an answer in Linq like: from p in db.table where p.column.AddMinutes(1) > ...
4
votes
1answer
151 views

How big of an impact does NUMA really have?

I was reading up on Non-Uniform Memory Access (NUMA) and I was wondering how much of a difference it can really make? Another way to word that, what level of throughput is required before this ...

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