Having an SQL database is well and good; unfortunately, having "SQL" merely implies the presence of a powerful database engine, and the situation you find may be comparable to merely buying an automobile engine, where in order to go out driving, you need to add in other components such as a body, steering wheel, wheels and tires, and the likes.
In the case of a database, the additional components that may need to be added to the database "engine" include:
Interactive Form/Transaction-oriented front end
There are a host of Web-to-DBMS tools available for Linux, but few tools in the style of Oracle SQL*Forms or Sybase PowerBuilder.
Non-interactive Batch/Transaction processor
For server-oriented DBMSes, some set of administration tools to support the DBA
MDB Tools is a planned set of libraries and utilities to facilitate exporting data from MS Access databases (mdb files) into a multiuser database such as Oracle Sybase , DB2, Informix , MySQL™, PostgreSQL , or similar.
These tools are often not tightly integrated with the RDBMS system
It does not run on Linux, and so does not, strictly speaking, belong here, but is a popular (expensive!) tool that many other data modelling tools emulate.
A toolset for interactively constructing database schemas along with documentation. Implemented in Java, and compatible with most SQL DBMSes at least insofar as they conform with the SQL-92 standard.
A "Java"-based tool that uses 21 to help construct a series of web pages analyzing a DBMS schema including diagrams of the interrelations between tables. By using JDBC, it can analyze schemas for numerous DBMSes including free ones such as "PostgreSQL" as well as proprietary ones such as 1 and 26.
SQL does not specify standards for these sorts of things, and database system vendors all get ample opportunity to "lock you in" to their tool sets by encouraging you to use their proprietary tools to do these things.
The realm of "4GL" languages unfortunately represents a sizable body of what may be characterized as proprietary languages to tie you either to a language vendor or to a database vendor.
The SQL/CLI (aka ODBC) SQL Call Level Interface provides a commonly-used interface that can allow the construction of "standardized" tools that are capable of accessing data from any sort of database system. Unfortunately, the main vendor promoting ODBC has been MSFT, and they have used every opportunity to try to promote their database products in their ODBC tool implementations.
You nonetheless are likely to need some sorts of tools to generate reports, queries, enter data, and do offline/background processing.
Many middleware interfaces have been proposed to resolve this; none are entirely satisfactory, as they still represent fairly proprietary systems that lock you into a "marriage" with their ways of doing things.
You thus might either embed SQL queries into web page source code to be interpreted by an Apache extension, or generate database updates from the results of an HTML form, via a CGI gateway, perhaps written in Perl or Python. Middleware tools include a lot of tools to aid in this sort of approach.
I have also written a document on Linux Application Frameworks that suggests ideas about how one might build up an architecture to deploy applications.
This subject is well worthy of an article with examples, some place like Linux Journal. To Do...
PostgreSQL has supported MVCC since version 6.5
Oracle and DB2 support something similar
InterBase implements "multigenerational concurrency control" which is equivalent.
A not-so-very technical discussion of Multi Version Concurrency Control - a discussion of the use of MVCC with Firebird .
SAP-DB apparently includes MVCC in its object database subsystem; unfortunately, it is not well documented.
dbMan is a simple SQL
monitor for common database system (PostgreSQL, Oracle, MySQL™
etc.). It's based on Perl , Tk and DBI
interfaces. It supports output window, command history buffer,
browse, editable browse, list of tables, table manager, plugins
support, language support,
for remote connection, SQL help, import and export tables,
browse queries, etc.
Tools to do database administration from a web browser.
Tables, views, and other database schema data
Execution and performance statistics
Queries, PL/SQL code
A web-based data dictionary browser for Oracle
pgAdmin II is a comprehensive database design and management tool for Win32 for use with PostgreSQL
SQLGraph using graphviz
This is a utility which will run through PostgreSQL system tables and returns HTML , DOT, and 2 styles of XML which describe the database. The HTML is human readable (via webbrowser). The first style of XML is actually the fileformat of Dia , a UML diagram tool. The second type of XML is similar to the HTML but in the Docbook 4 format. It enables you to mix in other docbook documentation via the XREFs, generating PDFs, HTML, RTF, or other formatted documents. Between these tools and JavaDoc with the appropriate XREFs, documentation about a project can be generated quickly and be easily updatable yet have a very professional look with some DSSSL work.
CASE Studio 2- database modeling tool. ER diagram, reverse engineering, SQL script...
This is a site where one may obtain lists of "sample data" of various sorts, freely sharable.
Benchw provides a toolset to benchmark the capabilities of several different database engines for data warehouse type activities. It is designed to provide a simple way to test data loading, index creation plus query performance in the spirit of TPC-H
Initially created for use with PostgreSQL.