15
votes
6answers
2k views

What is SQL Server “Denali”? What's new?

I found a new title called SQL Server "Denali" in the drop down list on MSDN, but I didn't find much information about it: What's New (this documentation is for preview only as I see) Top 9 New ...
10
votes
3answers
200 views

Are there any database engines which will intuit the join condition based on the existing foreign keys?

It seems strange to me that, when I've defined a foreign key, the engine cannot use this information to automatically figure out the correct JOIN expressions, but instead requires me to re-type the ...
6
votes
6answers
474 views

Which database engines will allow me to GRANT/REVOKE on a specific column?

If I have a table with a single column of sensitive data, and I want to grant broad use of the table without exposing that one column, I know that I can create a VIEW that gives them access to all the ...
10
votes
2answers
173 views

Is there anybody using the SQL Server feature to create groups of stored procedures differentiated by number?

The question refers to the number parameter in this msdn documentation If you don't you can create multiple stored procedures in SQL-Server differentiated by number and drop them with a single drop. ...
5
votes
3answers
962 views

How can a datapump export have its resource usage limited on windows?

Doing an export of a number of users causes high CPU and I/O usage. I can mitigate the effects of the CPU usage using Resource Manager and setting the export session to a low priority group, but how ...
15
votes
2answers
28k views

What is the difference between MySQL VARCHAR and TEXT data types?

After version 5.0.3 (which allowed VARCHAR to be 65,535 bytes and stopped truncating trailing spaces), is there any major difference between these two data types? I was reading the list of ...
14
votes
3answers
5k views

Is it common practice to mix InnoDB and MyISAM tables on same server?

I've got a single database of about 4.5GB running on a server with 8GB RAM. The vast majority of the tables are MyIsam (about 4.3GB), but I'm soon going to be converting some of them to InnoDB. (It's ...
3
votes
2answers
29 views

What can I do to find out since which release a given DBMS supports a feature, function, etc?

It is rather easy to find links describing a feature. In most cases there is no hint in which release the feature was introduced. Often the last resort is to google for the feature in combination ...
8
votes
2answers
798 views

What is the meaning of DOP in the context of SQL Server?

What is the meaning of DOP in the context of sql server?
10
votes
1answer
1k views

What is the impact of changing the index creation memory setting in SQL Server?

I am trying to create some indexes a SQL Server 2008 database but am getting the following error message. Msg 8606, Level 17, State 1, Line 1 This index operation requires 1024 KB of memory ...
3
votes
1answer
400 views

How to get the Oracle Text Index's underlying Virtual XML Document?

The Oracle Text Reference 10g states that when we index our table using multi-column datastore, the system concatenates the text columns, tagging the column text, and indexes the text as a virtual XML ...
12
votes
1answer
15k views

INT(5) vs SMALLINT(5)

In MySQL table definitions is there a different between INT(5) and SMALLINT(5)? Or do they both represent the same size?
6
votes
2answers
6k views

SQL Server 2008 log files have minimum sizes, what gives and how do I make them smaller?

Ok, to start with, I screwed up when I created the databases, using a create script roughly like so: (artificial linebreaks and names/paths for wrapping purposes) CREATE DATABASE [EXAMPLE] ON ...
8
votes
1answer
465 views

How can a datapump export have its resource usage limited on linux?

Doing an export of a number of users causes high CPU and I/O usage. I can mitigate the effects of the CPU usage using Resource Manager and setting the export session to a low priority group, but how ...
13
votes
3answers
3k views

What other databases have a feature similar to Oracle's Flashback Query?

I am interested to know what other databases have features similar to Oracle's Flashback Query. It would seem that any database that supports MVCC could have the feature, but which do? SO has this ...
25
votes
5answers
22k views

How do I shrink all files quickly for all databases?

In SQL Server (2008 in this case) how can I quickly shrink all the files, both log and data, for all databases on an instance? I could go through SSMS and right click each and choose Tasks -> Shrink, ...
4
votes
2answers
1k views

How do I stop refresh conflicts between Proactive Caching of facts and timed refresh of Dimensions in a SQL Server Analysis Service 2005 OLAP cube?

I have a SSAS 2005 OLAP cube which we've very nearly made into a ROLAP cube using a mixture of proactive caching for the fact partitions and timed refreshes for the dimension data. There are two fact ...
11
votes
2answers
4k views

How do I change the instance name in MS SQL 2005 without installing a new instance?

I have an instance that really has nothing on it, it's merely been installed (it was intended for one project, but that never actually got done on this server, the project was done in duplicate on ...
15
votes
3answers
28k views

Can I change the SID of an Oracle database?

The Server is Oracle Database 11g Enterprise Edition Release 11.1.0.7.0 - 64bit Is there an easy & quick way to change the SIDs of the test databases on the server? Dropping & recreating of ...
18
votes
3answers
33k views

How to change SQL Server collation

How could I change the SQL Server 2008 R2 Express Default Collation for the whole server and a particular database? Is there a way to do it using visual interface of SQL Server Management Studio? In ...
7
votes
1answer
4k views

Can I use OpenLDAP to authenticate users in Oracle?

I like to use OpenLDAP to authenticate my Oracle users. It should be possible to fetch at least the password from the directory. There appearently is something for the Oracle LDAP servers, but would ...
24
votes
3answers
13k views

What are the drawbacks with using UUID or GUID as a primary key?

I would like to build a distributed system. I need to store data in databases and it would be helpful to use an UUID or a GUID as a primary key on some tables. I assume it's a drawbacks with this ...
8
votes
3answers
3k views

Dynamic SQL in MySQL stored routines

According to the restrictions on stored routines and triggers, dynamic sql cannot be used (restriction lifted for stored procedures in version 5.0.13 and later). Why is this limitation in place? And ...
13
votes
6answers
19k views

What is the recommended RAID configuration for an Oracle database?

RAID (Redundant Arrays of Inexpensive Disks) comes with different configurations (RAID-0, RAID-1...). What is the recommended RAID configuration that I should set up and use when installing an Oracle ...
6
votes
1answer
1k views

What are some important MySQL status variables to keep an eye on? [closed]

I'm a fairly new DBA with a programming background. As such, I like to build tools to manage tasks to help me familiarize myself with the intricacies of a technology. In this case, I am managing ...
10
votes
3answers
1k views

Speeding up conversion of MyISAM to InnoDB

I've got a mysql 5.1 server with a database of approximately 450 tables, taking up 4GB . The vast majority of these tables (all but 2) are MyIsam. This has been fine for the most part (don't need ...
15
votes
3answers
8k views

Code to simulate deadlock

I am testing my application I need some code that stable simulates the deadlock on database site (sql script if possible). Thank you. ADDED: Reproducing deadlocks involving only one table
10
votes
2answers
2k views

Security for Application Developers doing PL/SQL work in Oracle

How do you handle the lack of Schema level privileges in Oracle? Oracle’s security architecture works well for applications that only need object level privileges and it works well for DBAs that need ...
5
votes
1answer
134 views

Where to put a database in case of IP failover?

I understand that to achieve some level of availability of an online application it is possible to organize an environment with a redundancy using an IP failover mechanism and switching between ...
22
votes
4answers
8k views

Why is OS authentication considered poor security for Oracle databases?

Oracle is deprecating OS authentication according to the Oracle Database Security Guide, which says Be aware that the REMOTE_OS_AUTHENT parameter was deprecated in Oracle Database 11g Release ...
6
votes
3answers
452 views

Online resource for writing Access SQL statements

I am looking for an online resource for writing Access SQL statements. I write queries using SQL because the UI puts limitations on what can be queried. I have been using w3schools for reference, ...
9
votes
2answers
3k views

Why can't I read Oracles CLOB columns via SQL-SERVER 2008 linked server?

I want to access data in an Oracle 11g database from SQL-Server 2008 I set up a linked server and when I execute select * from [Link_server_name]..Oracle_schema.Oracle_table and Oracle_table ...
2
votes
2answers
1k views

Is it better to store calculated values or recalculate them on request? [duplicate]

Possible Duplicate: Storing vs calculating aggregate values At an old job, we had this database, it wasn't normalized rigth, some tables wheren't used anymore, it was patch after patch. In ...
4
votes
2answers
391 views

different login credentials based on user

I run a PHP symfony-framework web app for my company and it uses a single database login for all connections, whether the user is an admin or a client. I know that higher security systems often use ...
7
votes
2answers
377 views

Is this a new common pattern in Oracle Where exists ( Select NULL FROM…)?

Years ago, it was common to write where exists (Select * from some_table where some_condition) Last year I noticed that many t-sql scripts switched to using the number 1 instead of the star where ...
1
vote
1answer
130 views

version controll application/system for mysql databases [duplicate]

Possible Duplicate: Keeping track of schema changes Hello, How do you keep your mysql database schema under version control.
17
votes
8answers
12k views

How do you version your Oracle database changes?

I am interested to know what methods other people are using to keep track of changes made to the database including table definition changes, new objects, packages changes, etc. Do you use flat files ...
11
votes
5answers
2k views

Does it make sense to use SQL Server's bracket notation in hand written code?

Code generators tend to be simpler when they generate output using the new Microsoft bracket notation ([]) for nearly everything. When I first saw it, I though wow a reincarnation of the somewhat ...
0
votes
3answers
184 views

What database platform better at scaling? [closed]

I am planning a for a database that i expect will be very big in terms of number of records rather than tables and batabases. My Question is what product (i.e, SQL 2008, Cassandra, Azure) handles ...
8
votes
4answers
10k views

Feature comparison: Oracle Database and Microsoft SQL Server [closed]

Many companies have a heavy influence on market and technologies around them, and you often compare the products before you choose, e. g. I liked Oracle APEX, its flexibility and features, and we're ...
16
votes
4answers
8k views

Task scheduler for SQL Server Express

I have an ASP.NET MVC app which works with database under SQL Server 2008 R2 Express edition. There is a need to perform a regular task on updating some records in the database. Unfortunately the ...
40
votes
3answers
10k views

Guid vs INT - Which is better as a primary key?

I've being reading around reasons to use or not Guid and int. int is smaller, faster, easy to remember, keeps a chronological sequence. And as for Guid, the only advantage I found is that it is ...
6
votes
2answers
119 views

Is there a good “rule of thumb” for translating EXPLAIN cost to (wall-clock) runtime?

From time to time, consumers of my database processes will ask for an estimate of when a given task will be done. While I feel like I know how to read an EXPLAIN in most database engines, I have ...
17
votes
2answers
1k views

Which collation should I choose for a muiti-language website?

Does a collation have any influence over a query speed? Does the size of a table change depending of the collation? If I want to build a website that must support all possible languages (lets take ...
7
votes
3answers
193 views

Is there a performance gain by handling data with stored procedures versus feeding it into functions after retrieval?

Title sums it up. I'm reasonably well off with PHP, and comfortable getting it to do what I need it to with values pulled from MySQL, however in the interest of expanding my knowledge I've been ...
11
votes
1answer
676 views

SQL Server - How are data pages stored when using a clustered index

I recently heard that the data pages in a clustered index aren't stored contiguously. Is this true? Perhaps data pages are normally stored contiguously with some exceptions to the rule? Or perhaps I ...
4
votes
1answer
80 views

Can I activate PITR after the DB has been used

My Postgres-Server is running for quite a while and contains probably 4-5 GB of data. Backups are done using dumps, and this works ok. Though not most efficient, it just works. Due to future growth ...
47
votes
4answers
5k views

Storing vs calculating aggregate values

Are there any guidelines or rules of thumb to determine when to store aggregate values and when to calculate them on the fly? For example, suppose I have widgets which users can rate (see schema ...
21
votes
3answers
4k views

Character vs Integer primary keys

I'm designing a database with multiple lookup tables containing possible attributes of the main entities. I'm thinking of using a 4 or 5-character key to identify these lookup values rather than an ...
15
votes
8answers
6k views

Must-read Books for DBA [closed]

This question is almost mandatory in any SE site for basic reference. Please post only books with permanently value for DBAs in general. The post should be a must read book, the classical ones, the ...

15 30 50 per page