I'm deciding what database to use for my project, but I've only ever used relational databases (Oracle, MySQL) so for my web project I figured I'd use MySQL with PHPMyAdmin for DBMS.
But I'd like to know more about other database types, succinctly if possible, before I finally decide.
Thanks in advance!
I have a big SQL Server 2012 database.
I want to split it into preferences and data.
However I find that SQL Server does not seem to support the idea of dividing your data up into object oriented databases. It seems to rely on everything being in the same database.
For example foreign keys are not supported in database. Also cross database joins are a real pain to do.
How would someone typically go about doing this? Is it just a limitation of SQL Server that I should use the same DB for everything?
SQl Server provides partitioning feature. As per wikipedia
A partition is a division of a logical database or its constituting elements into distinct independent parts. Database partitioning is normally done for manageability, performance or availability reasons
1.Horizontal partitioning
2.Vertical partitioning
Each has it is own file group.it can be configured
Visit this links that should help
MSDN
SQLAuthority
I am sure there are plenty of tutorials out there.
SQL Server is a relational database, so there really shouldn't be an expectation that it would support a fundamentally different architecture implied by an object or object-oriented database.
I don't understand your comment that "foreign keys are not supported in database." Foreign keys are all part of the integrity constraints in SQL Server, and a detail description of how to create them is available here
I think you might want to be more specific about the type of data you're trying to split up, and why you want to put them in physically separate databases. A refinement of your problem might help us provide better answers.
Does anyone know a good reference to look into what Object Relational features are available in SQL Server (any version)? I found a really good summery for Oracle but all I can find for SQL Server is information about LINQ to SQL, which is good stuff, but I'm looking for more power in the database like defined types, nested tables, etc.
I know you can use CLR types in SQL Server, and that would be interesting to me too, I just am looking for a good place to read about all the OR features it has.
PS. I'm willing to purchase a book.
You should read Best Practices for Semantic Data Modeling for Performance and Scalability.
The SQL Server is not as object relational as one might expect - not that long ago I realized that it does not (even) support table inheritance.
As a Java Developper using JPA/Hibernate, I am looking for a will help diff a database that has been generated by Hibernate with a production database.
I've already looked at LiquiBase's abilities LiquiBase which is quite nice... Unfortunlately it is plagued by some weird bugs:
Re-Create Foreign Keys for no reason
Re-Create Indexes for no reason
I'm not entirely sure that it's Liquibase's fault as much as the JDBC Driver Implementation that are not consistent with the specification. I would be probably be plagued by the same issues if I even tried to roll out my own.
I am looking for a non Java-based solution that would support:
MySQL
PostgreSQL
Oracle
DB2
I like DB Data Difftective.
Have you looked at ModelRight?
If you just need to diff or "patch" data values (not structure), then Open Source DiffKit will handle this nicely for you:
http://www.diffkit.org
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We all have our favourite database. If you look objectively at your chosen database, what drawbacks does it have and what could be improved?
The rules:
One reply per drawback with;
a short description of the limitation, followed by;
a more detailed description, an explanation of how it could be done better or an example of another technology that does not have the same limitation.
Do not diss any database that you haven't used extensively. It is easy to take potshots at other technologies but we want to learn form your experience, not your prejudice.
Oracle databases are quite expensive
Oracle does what it does well but the licensing costs are horrendous. That has been improved by the release of Oracle XE but the limitations of that mean that it is a growth constraint on you solution.
Database Microsoft SQL Server 2005
Defect Lack of "INSERT OR UPDATE"
Description
Often you need to either insert or update a record in a table, depending on whether the record is present or not. Not having an atomic operation to do so leads to unnecessary transactions.
This does not happen with MySQL or SQLServer 2008.
Database PostgreSQL
Defect No SQL Profiler
We asked the developers about this at a recent conference and I understand it's now something they're looking to implement.
I love the flexibility of sequences in Oracle as compared with other databases autoincrements, but the inability to set seq.nextval as a default for a pk column is somewhat annoying, and must be trivial to fix.
Database Microsoft SQL Server
Defect Huge licensing cost
Description
SQL Server has great features and it integrates very well with .NET development. The issue is that when you have to scale up from a shared database to a dedicated database, licensing costs are really high. This, in effect, leads to databases which should really run on a dedicated server, being hosted on shared servers with performance and security issues.
This does not happen with MySQL or PostgreSQL.
Database Microsoft SQL Server 2005
Defect Badly implemented UI
Description
SQL Server management studio does not offer a great user experience:
Tabbing behaviour is weird: you are always looking for the right tab
Keeps on crashing on 64-bit versions
Missing some features of preceding version, like overview of grants of stored procedures
This does not happen with version 2000.
Database MySQL
Defect Server will start up with damaged tables
Description
If MySQL has a damaged table - from either being killed during a write or some other failure - it will quite happily start up and allow the user to carry on as if the problem does not exist. Granted it will produce some error messages in the log, but from my experience this doesn't help when you're trying to figure out why an application is behaving oddly.
Most other databases will detect and repair the error on startup or simply refuse to start with any sort of corruption.
Database MySQL 5.0.x and above
Defect Ring replication errors lead to inconsistent data on different nodes
Description
The most serious problem in production we face at the moment is that in a MySQL ring the ring itself produces an error and stops replicating.
Building a ring (or Master-Master-replication) is possible since 5.x.x: You chain the databases in a "ring" so that the replicate data to each other. Every database-node gets all the changes from all other nodes.
We assume that the error lies behind autoincrement- failures. This is known from normal replication, too, but in the new version there are no sufficinet error messages in the error log. I highly recommend not to use this feature in MySQL as long as the problems here are not fixed.
Database Oracle
Defect Did not handle long datatype well for too long
Description
Oracle only had the long datatype until 9i (I believe) at which point it was deprecated in favor of the LOBs. There is a ton of code out there, however, which still has longs and all of the related restrictions. The biggest of which was that each table could only have one long column and it had to be at the end of the columns. See here for a more exhaustive list of restricitons on the long.
Database Oracle
Problem Temp table definitions are not private
Description Many databases (eg Postgres and Sybase) allow you to create temp tables on the fly, insert into them, add indexes if you want, then query from them. Oracle has temp tables, but the temp table definitions exist in a global name space. Therefore the temp table has to be created by a DBA, you need to synchronize between the table definition they used and your code, and if two pieces of code want similar (but not identical) table definitions, they need to use different names. These differences make temp tables far less convenient for developers.
Yes, I understand the benefits for the query optimizer of having global definitions. However for me the lack of convenience makes Oracle's temp tables virtually useless for me, while I use them very intensively in Postgres.
Database: Oracle
Problem: The names of tables, procedures, columns, etc cannot exceed 30 characters. This is infuriating.
Problem: It's slapdash JDBC compliance. For example, stored procedures do not return results sets in a JDBC-compliant way, but instead of a proprietary OUT parameter type. This means you can't use higher-level JDBC abstractions.
Database MySQL
Defect Foreign Keys supported only on some table types
Description
Enough said. It has obvious maintenance implications.
From the MySQL manual
Foreign keys definitions are subject to the following conditions:
Both tables must be InnoDB tables and they must not be TEMPORARY tables.
And here:
For storage engines other than InnoDB, MySQL Server parses the FOREIGN KEY syntax in CREATE TABLE statements, but does not use or store it.
This does not happen with any other major DB.
PostgreSQL doesn't have a good failover solution, but I understand they're working on it.
Database : Sql Compact Edition
Drawback : Stored procedures are not supported.
Regardless of this limitation, this DB has its' uses especially as a client cache for application that can be smart client or distributed to mobile platforms.
Database Oracle
Defect Granularity of grants on packages
Description
You can only grant permissions on packages and not on stored procedures inside packages. Or alternatively, you can grant permissions on single stored procedures but then you put them outside of packages. This requires you to know up front who will use which stored procedure and it is really hard to refactor.
This does not happen with SQL Server.
Database Microsoft SQL Server 2005
Defect Lack of array type parameters
Description
Useful in searches, a lot of times you need to pass a series of values to be matched against. In SQL 2005 you can do a workaround by using CLR inside SQLServer. Given the usefulness it would make more sense to have this feature out of the box.
This does not happen with SQL Server 2008 or Oracle.
Database Postgres
Defect No analytic queries
Description
Analytic queries, introduced by Oracle, are part of the SQL 2003 standard. Unfortunately Postgres hasn't implemented them yet.
Database : PostgreSQL
**Problem : ** is that connector for C# for example are not really up-to-date and crash with advanced feature.
Database: All
Drawback - Poor design by people who didn't think it was important to know what you were doing when you designed a datbase. Far more problmes caused in all databases by bad design than from any missing feature. So I suppose they are all missing the "read my mind and figure out the best solution without me having to think" feature.
Any SQL DBMS
Defect: Duplicate rows
One of the virtues of the relational model is that it represents everything without duplicate tuples, i.e. using relations, which have keys and no duplicates. Unfortunately SQL isn't built that way. This makes the database developer's life needlessly difficult. SQL developers have to deal with tables without keys and debug queries that return duplicate rows.