8
votes
9answers
9k views

What tools are there for data masking? (MySQL, Linux) [closed]

I'm looking for (ideally free, open-source) data masking tools. Do any such exist? Note: this related question deals with tools for generating test data, but in this question I'm more interested in ...
8
votes
1answer
1k views

BLOBs or references in PostgreSQL

I need to store binary data files in a PostgreSQL database which runs on an Ubuntu server. Initially there will be a few dozen files of approximately 250kb in size each. However, the number of files ...
4
votes
5answers
2k views

What is the best use of memory in MySQL?

I have a MySql server with 2Gb of memory. What's the best configuration to use then with best results? How can I "distribute" this memory fine to MySql server?
6
votes
4answers
3k views

MySQL Replication - Introduce new Slave to replication

I've recently taken on a sys admin position managing a group of 20 (or so) servers. One thing I haven't dealt with before (apart from in a test situation), is introducing a new slave to the MySQL ...
3
votes
2answers
2k views

Connection Pooling for PHP based website using Oracle 11g database

I am using Oracle 11g database server and now I am getting to see that OCI's persistent connection isn't much of a use, and a new connection is created anyway when a new user accesses the page. I ...
5
votes
3answers
2k views

Building Dynamic SQL-Server Where Clause

Let us review this dba.exchange Oracle question for SQL-Server. This is SaUce's code, after a little formatting: CREATE PROCEDURE GetCustomer @FirstN nvarchar(20) = NULL, @LastN ...
18
votes
3answers
7k views

Is it a good idea/approach to index a VARCHAR column?

We're using PostgreSQL v8.2.3. There are tables involved: EMPLOYEE and EMAILLIST. Table 1: EMPLOYEE (column1, column2, email1, email2, column5, column6) Table 2: EMAILLIST (email) 2 tables are ...
2
votes
8answers
4k views

What database front end do you use? [closed]

What database front end do you use? It should let you manage databases, tables, indexes and ideally even data records. And it should ideally be free so we can all use it too. Databases that it could ...
3
votes
2answers
1k views

How to connect external database to AppEngine?

Are there any ways (better than using UrlFetch) to connect to any external database from AppEngine? I already know about hosted SQL databases in App Engine for Business, but they are not free and ...
7
votes
3answers
619 views

Inserting and updating and selecting at thousands of times per second

I have a table that gets inserted, updated and selected from thousands of times within one second. I am having deadlock issues though. The database has 2-5 simultaneous 1000+ row inserts using Linq ...
3
votes
3answers
176 views

Obtaining gratis copy of the SQL specification?

There used to be a public link to the JTC 1/SC 32 working drafts of 9075:2003, but the link I had has not worked since they started on the post-2003 revisions. Given that there are publicly available ...
5
votes
3answers
4k views

Why does this Entity Framework query perform so bad in MySQL?

Let me give you a little setup. We have a InnoDB table on MySQL 5.1 with close to 20 million records, no foreign keys, and proper indexes for queries we do. We are using the latest 6.3.5 MySQL ...
2
votes
3answers
1k views

How do I join two tables on two different instances of DB2?

There are two instances of DB2 running on the same machine. One has a table aliased to the a table in the other one. Is there a way to do this in DB2 or does it have to be done via an external tool? ...
13
votes
2answers
1k views

Is there any tangible difference between a unique clustered index and a clustered primary key?

I understand that there may be a difference in meaning or intent between the two, but are there any behavioral or performance differences between a clustered primary key and a clustered unique index?
17
votes
3answers
3k views

Why would someone put `where 1=1` in a query?

I came across a view in our database today where the first statement in the where clause was where 1 = 1. Shouldn't this return true for every record? Why would someone write this if it isn't ...
11
votes
4answers
3k views

Is there any benefit of a primary key that comprises all columns of the table?

I have a table with four columns that are all non-nullable, and the data is such that all four are needed to distinguish a unique record. This means that if I were to make a primary key, it would need ...
6
votes
1answer
515 views

Can PostgreSQL tell me what configuration files it's using?

I am having trouble with some changes I'm making to a configuration file. I think PostgreSQL is not using the ones I'm modifying. Is there any way to get postgres (maybe some environment variable) to ...
14
votes
3answers
5k views

Find out what queries are causing the biggest amount of network traffic

On a production SQL server I am seeing intermittent enormous spikes in data traffic. Up to 200Mbit/s which is causing NETWORK IO waits which in turn cause query timeouts. How can I find out what ...
6
votes
2answers
949 views

Get records between time span

I would like to retrieve records between time spans,All i have is this snippet of string indicating the time span 9:00 AM - 10:00 AM below is the table schema CREATE TABLE [dbo].[Samples]( [RID] ...
4
votes
2answers
2k views

What's a free client for Oracle 8 on Linux / Ubuntu? [closed]

I need to connect to a legacy Oracle 8 database. Oracle SQL Developer would be my tool of choice, but the current version doesn't support Oracle 8 anymore. I tried Squirrel too, but the connection ...
10
votes
2answers
2k views

How large is “too large” for SQL 2008 Web Edition?

For our soon-to-be-hosted application I need to choose between SQL Server 2008 Web edition and SQL Server 2008 Enterprise edition. There isn't any "must-have" functionality: the application currently ...
8
votes
2answers
1k views

Possible to run two DBCC INDEXDEFRAG commands simultaneously, each on a different table?

I am currently running a script which performs a DBCC INDEXDEFRAG on every table in a SQL Server 2005 database, one table at a time. Using DBCC DBREINDEX instead of INDEXDEFRAG is not an option, due ...
5
votes
3answers
1k views

SQL Server renaming table from another database

Is there a way in SQL Server to rename a table in another database? When you are in current database and migrating data over to another database in the TEMP table and then renaming TEMP table in that ...
27
votes
7answers
14k views

Is it better to store images in a BLOB or just the URL? [duplicate]

Possible Duplicate: Files - in the database or not? I was wondering if there's any good reason to still use blob fields in a database. A couple of years ago I worked with a DB with a bunch ...
4
votes
3answers
377 views

Multi-database object-oriented proxy

Do you know if there is a system/product/technique which would allow to "wrap" one or more relational databases into one object-oriented virtual database (or could we call it a "multi-database ...
5
votes
1answer
182 views

Is my function nondeterministic one

I have two functions: fn_Without_Param and fn_With_Param CREATE FUNCTION [dbo].[fn_Without_Param] ( ) ... INNER JOIN .. ON .. AND SubmitDate = CONVERT( varchar(10), GETUTCDATE(), 101 ) and /* ...
4
votes
1answer
112 views

Data transformation implementation

My company's database, I am working with, makes available a data to a lot of external applications. So I need to transform the same data to a lot of dynamic views. I can see that a former database ...
5
votes
1answer
321 views

How can I benchmark the performance of UDFs to figure out which one is faster?

Basically I have two scalar UDFs that output the same data, one that uses a cursor and one that uses a recursive CTE. I want to determine which one should be used and discard the other; I'd prefer to ...
0
votes
0answers
169 views

What is the best query to use to monitor a SQL Server database's status?

I want to be able to run a query to get the crucial information about a database's status. I.e., I want the query to be able to tell what whether or not the database is in a good state. This is the ...
16
votes
4answers
11k views

What is the best query to use to monitor a SQL Server database's status?

I want to be able to run a query to get the crucial information about a database's status. I.e., I want the query to be able to tell what whether or not the database is in a good state. This is the ...
13
votes
6answers
30k views

Best way to delete very large recordset in Oracle

I manage an application which has a very large (nearly 1TB of data with more than 500 million rows in one table) Oracle database back end. The database doesn't really do anything (no SProcs, no ...
5
votes
3answers
1k views

Remove field from composite key and collate duplicate data

I'm looking for the best way to go about changing the primary key on a table in my DB without having to completely reinsert data from files again. The modification I'm going to make is going to ...
4
votes
2answers
1k views

Identify which parameters were passed to a procedure (Oracle)

Procedures in PL/SQL can have default values for parameters, but the caller can pass values that are identical to the default values. Is there a way from within the PL/SQL to determine whether a ...
3
votes
3answers
3k views

Confirm that my.cnf file has loaded OK

Does anyone know if there is a way to confirm if any my.cnf file is being read by MySQL? I only have the one my.cnf on the machine (and there are no my.ini files) which I have in /etc/my.cnf. When I ...
3
votes
1answer
146 views

Oracle setup required for heavy-ish load

I am trying to make a comparison between a system setup using Hadoop and HBase and achieving the same using Oracle DB as back end. I lack knowledge on the Oracle side of things so come to a fair ...
18
votes
11answers
49k views

Eliminate duplicates in ListAgg (Oracle)

Prior to Oracle 11.2 I was using a custom aggregate function to concatenate a column into a row. 11.2 Added the LISTAGG function, so I am trying to use that instead. My problem is that I need to ...
9
votes
2answers
5k views

SQL Server 2008 - Cross database performance on same physical machine and server instance

Is there any performance hit when doing a select across another DB on the same physical machine? So I have 2 databases on the same physical machine running within the same SQL 2008 instance. For ...
7
votes
4answers
13k views

Replicating a remote MySQL database to MS SQL Server 2008

I want to replicate the contents of a MySQL database to a MS SQL Server 2008 database. Is this possible? Can anyone outline the steps required in order to achieve this? Thanks.
5
votes
2answers
1k views

How do I search to see if a MySQL user exists on the system?

I'm not finding a user by show grants for 'username'@'localhost'' I'm thinking that perhaps the username is slightly different, so I want to do a wildcard search of all the database users. How can I ...
9
votes
1answer
758 views

Is there a reliable way to determine when you should run DBCC CLEANTABLE to reclaim space?

Lately, instead of just growing files when they near 80% file utilization, I've been more proactive at reclaiming space via the usual tricks like defragmenting heaps, adding & dropping clustered ...
6
votes
1answer
566 views

How does MS SQL Server decide when it can use “Parallelism” when executing queries?

How does MS SQL Server decide when it can use "Parallelism" when executing queries? I recently posted another question here that, when looking at the actual execution plan used parallelism when I had ...
6
votes
3answers
364 views

Is the SQL Server IsShutdown property useful to determine whether a database is in a good state?

My company has a tool that monitors statuses on servers, services, databases, etc. We monitor a number of on-site servers for our customers. One particular simple check performed is to determine ...
8
votes
4answers
9k views

Audit logins on MySQL database

Is there a way to audit logins to MySQL? I'd like to be able to create a username for each employee and thereby create an audit trail of logins. However, googling has turned up no good results. The ...
5
votes
4answers
11k views

Building Dynamic Oracle Where Clause

I'm working on application that uses dynamic query to do a select statement based on user input, after discussing security with DBAs they want me to convert my dynamic select statement into Stored ...
5
votes
1answer
640 views

Case Behavior Changed Between 11.2.0.1 and 11.2.0.2

I have a case open with Oracle and they say they can't reproduce this. Running the following in 11.2.0.1 or lower produces two rows from both of these queries, but in 11.2.0.2 the second query ...
6
votes
3answers
26k views

How to get rid of ORA-28002 message the password will expire within 6 days?

I have a user getting an ORA-28002 indicating that the password will expire within six days. I ran the following: ALTER PROFILE DEFAULT LIMIT PASSWORD_LIFE_TIME UNLIMITED; But when I try to log ...
2
votes
1answer
540 views

How to customize Deploy feature in VS2010 for SQL CLR projects?

The default deployment script for SQL CLR objects in VS2010 seems to require one to set the target database to SET TRUSTWORTHY ON and tries to enable vardecimal storage at the database level. On our ...
7
votes
3answers
20k views

Calculating percentage of a row over total sum

Apologies for the bad title, I wasn't sure what would be a good title for this. This is currently (simplified view of the) data I'm working with Agent | Commission ---------|------------ ...
5
votes
4answers
8k views

Emulate REGEXP like behaviour in DB2 SQL

I posted the same on stackoverflow (please, let me know if I have to delete one). I'm working on a DB2 database and as far as I can see regexp is not supported (without additional libraries). So I ...
26
votes
2answers
1k views

Where can I find database tuning exercises for learning?

As a developer, often DBAs take responsibility for resolving performance issues at the database level so we don't get that much experience diagnosing, tuning, refactoring queries etc. I'm looking ...

15 30 50 per page