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45

NoSQL stands for "Not only SQL" and usually means that the database is not a relational database, which have been very popular the last decades. The reason why NoSQL has been so popular the last few years is mainly because, when a relational database grows out of one server, it is no longer that easy to use. In other words, they don't scale out very well ...


22

If there is one thing I can say about MySQL is that InnODB, its transactional (ACID-compliant) storage engine, is indeed multithreaded. However, it is as multithreaded as YOU CONFIGURE IT !!! Even right "out of the box," InnoDB performs great in a single CPU environment given its default settings. To take advantage of InnoDB multithreading capabilities, you ...


21

First impressions Depending on your performance requirements, 100TB is a fairly aggressive data volume. If you want Oracle, you should check out their Exadata systems. Also, take a look at the offerings from Netezza or Teradata. With that volume of selects you might want to look at an OLAP based front end or at least fairly aggressive use of ...


17

NoSQL is a very broad term and typically is referred to as meaning "Not Only SQL." The term is dropping out of favor in the non-RDBMS community. You'll find that NoSQL database have few common characteristics. They can be roughly divided into a few categories: key/value stores Bigtable inspired databases (based on the Google Bigtable paper) Dynamo ...


15

Here is my opinion: Usually the bottleneck (or slowest part) of a DB system is the disk. The CPU only spikes during arithmetic operations, processing, or any other task that the CPU does. With proper architecture, multithreading can help to offset the load of a query onto the CPU instead of doing the slow disk reads/writes. There are cases where it is ...


14

This solution is called a multi-tenant design where each tenant (customer) has their own database. Given that, there are some other considerations to the alternative approach which is a single database: With a single database, everyone must be on the same version no matter what. It isn't possible to upgrade some customers and not others. This can be ...


14

Normalization absolutely is used in the real world... and hopefully you know that 3NF is only the third one of... what is is now, 8? But 3NF should be an easy target. However... I would venture to say that there could not be such a tool. Normalization, technically, is an attribute of each table. Within a given database, different tables may have ...


13

There is no reason to speculate whether Oracle "will" continue developing MySQL actively. The facts are easy to find out: look at the changelog and preview release announcements. The truth is that Oracle has accelerated MySQL development faster than it's ever happened before, and the releases are really good quality too, unlike Sun's 5.1 release or MySQL ...


11

I can only attempt to answer for Oracle and postgres. After using Oracle exclusively for years, and postgres only for the last two years or so, I love postgres. There are so many small ways it is more convenient to use than Oracle, and it shares many of the crucial benefits (such as MVCC). It is easier to administer, reliable, has excellent documentation, ...


10

I think now is the time to play with MariaDB (just like now is the time to play with anything like this). Personally, I would hold off until I know a few more devs who have deployed MariaDB onto a live customer site before doing it myself. Some situations could call for a change of application but something as serious as changing your database engine is not ...


10

NoSQL is a kind of database that doesn't have a fixed schema like a traditional RDBMS does. With the NoSQL databases the schema is defined by the developer at run time. They don't write normal SQL statements against the database, but instead use an API to get the data that they need. The NoSQL databases can usually scale across different physical servers ...


10

A list can be found on Wikipedia. I think the overwhelming leader in embedded sql databases is sqlite. Found everywhere!


10

I don't see how anyone could make such a statement without having some actual facts to back it up. If your queries are CPU bound, then you should look to find ways to reduce that bottleneck. It sounds as if your boss feels that a denormalized database will perform best, but I don't know enough about your application to say if that is right or not. What will ...


10

All a primary key is is a value that we have determined is the value that is of utmost importance in a record. Whether that key is a signed int, an unsigned int, a string, a blob (actually, there are limits) or a UUID (or whatever name it takes today), the fact still stands that it is a key, and that it is the thing of utmost importance. Since we're not ...


10

IMO you are making what is probably a pretty common mistake when it comes to web pages which is to assume that the answer to performance problems due to initial result size on MySQL is to jump to NoSQL solutions often with little understanding of what the tradeoffs are or how to use them appropriately and effectively. I would be surprised if a well-tuned db ...


9

In Oracle you can use the built in DBMS_ALERT package to facilitate this. DBMS_ALERT supports asynchronous notification of database events (alerts). By appropriate use of this package and database triggers, an application can notify itself whenever values of interest in the database are changed. Suppose a graphics tool is displaying ...


9

Oracle Apex. A handy, easy-to-use web application environment built right into the database. Quite simply it makes it very simple to deploy 'single-box' applications with the web ui/application logic/database in a single integrated package. PS. 11g XE (currently in beta) expands the storage to over 10GB.


9

Here is my opinion: If you are having very few updates/deletes you can increase the pagefill factor to 95%. This will save on space and reads. Do some testing though. Partition the table based on a broad category like year. Put these partitions on different filegroups.


9

If you can't scale a major RDBMS then your database design (includes indexing, queries and the like) or hardware is wrong. The choice of platform is almost irrelevant. It is that simple. Especially when you mention "few hundred megabytes" which implies low volumes (I mean a few dozen writes per second)


9

Defragmentation strategies help improve scan speed to/from disk. The wide variety of opinions is because an environment's ideal defragmentation strategy should depends on many different factors. There are also multiple potential layers of fragmentation in play. Saying that your databases are stored on a SAN isn't enough information. For example: Are ...


9

David Hay's Enterprise Model Patterns. This is a beast of a book, but has some great patterns. Conventions of Thought. More stuff on MRP. A Meta-Data Map . Haven't read this one. Len Silverston's Data Model Resource Book Vol. 1. Your main data model patterns. Data Model Resource Book Vol. 2. Case studies by industry. Data Model Resource Book Vol. ...


9

To be very fast, the database should only use memory and not disc since disc operations usually takes much longer time. But then your data aren't persistent in case of a crash. What you could do is assynchronous disk operations, by that most of your writes will be persistent but it's not guaranteed that the last few writes are persistent. If this is okey for ...


8

You should fully tune the MySQL Environment, particularly your InnoDB settings. (See the bottom of my Answer for tuning tips). This would be much better than fighting Amazon for elbow room in RAM/Disk. Why did I say fight? If you just spun up an Amazon RDS instance of MySQL, you would subject yourself to whatever constraints are given. All models of MySQL ...


8

Some other options to consider when dealing with massive data volumes like this include: Everything that @ConcernedOfTunbridgeWells posted Greenplum from EMC Parallel Data Warehouse from Microsoft Don't plan on skimping on hardware costs anywhere. A system with these sorts of specs is going to cost you some big bucks.


8

The first thing that comes to mind is a particular RDBMS that's familiar to me. I recognize, however, that it may not be the best for this application. So, my advice is to go with a database that are familiar to you. If you're familiar with Redis or MongoDB, then go with one of those. If you're more familiar with SQLite, then chose that. On a database ...


8

SQL Server 2000, 2005, 2008 has this capability GRANT { ALL [ PRIVILEGES ] } | permission [ ( column [ ,...n ] ) ] [ ,...n ] [ ON [ class :: ] securable ] TO principal [ ,...n ] [ WITH GRANT OPTION ] [ AS principal ] ADDED In SQL Server 2005, 2008 it is possible to encrypt a column of data by using symmetric encryption, see ...


8

There are a number of options and please don't limit yourself to my answer here. In particular you may find array-native databases to be of help. My answer is going to be specifically about your questions on SQL-based databases. It sounds to me like this is a question of geospacial information. SQL-based databases are in fact used in such fields quite ...


8

Trying to normalize addresses is generally a bad idea. There isn't a lot of value to normalizing addresses. Both of your designs are inappropriate for the vast majority of systems. There are two things you typically do with addresses: Use them to send mail or packages to that location. Use them to do geospatial analysis on that location. Since you ...


7

Certain database vendors also provide integrated message buses that your app can simply subscribe to: Oracle Advanced Queueing IBM DB2 with MQseries (now called WebSphere MQ) Sybase RTMS An alternative would be to route the data into the database in the first place via a message bus like Tibco/RV and simply "branch" it, on stream going into the DB and ...


7

Some implementations of SQL do recognise x = NULL as equality, the ISO/ANSI standard on the other hand does not. In SQL Server for instance, SET ANSI_NULLS OFF results in (NULL = NULL) = true. SET ANSI_NULLS OFF SELECT CASE WHEN NULL = NULL THEN 1 ELSE 0 END SET ANSI_NULLS ON SELECT CASE WHEN NULL = NULL THEN 1 ELSE 0 END



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