Posts Tagged: data structures

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Rarely Used But Useful PostgreSQL Features

I'm an avid user of SQL and the variety of - frequently overlooked - features it provides. However, unfortunately the possibilities of SQL and modern, advanced open source incarnations of RDBMS such as PostgreSQL aren't utilised to the extent they could be when developing web or enterprise applications today. More often than not SQL database are perceived as a mere data store for persisting object-oriented data, which can give rise to the famous object-relational impedance mismatch. SQL servers, PostgreSQL in particular, are capable ... Read more

Sharing and exploring data models and database patterns

Somewhat in the vein of last week's post, I'd like to share a new service called dbpatterns with you. dbpatterns allows you to create ER models in the browser and share them with other users. If a particular pattern or model suits your needs you can directly export its DDL for PostgreSQL, SQLite, MySQL or Oracle RDBMS. I really appreciate the idea of promoting and sharing best practices for database systems. While object-oriented software design patterns are rather common (though some particular ... Read more

Hands-on SQL Tips: Sentinels And Window Functions

Sometimes when displaying data in an application you want the amount of data (rows, individual data points etc.) to be limited for the app to stay responsive and to allow the user to more easily scan and browse the data set. In SQL this is commonly done using a LIMIT statement: SELECT * FROM table LIMIT 100 Now, what if you want to not only display the data but also inform the user in case the total number of rows in the table ... Read more