making apps, making webs.

In the article on his blog Peter asks " How much faster is Redis at storing a blob of JSON compared to PostgreSQL? ". Answer: 14x slower. Seems about right. Usually Redis is about 4x faster for a simple query like that compared to using PostgreSQL as a cache in my experience. It's why so many people use Redis as a cache. But I'd suggest PostgreSQL is good enough to act as a cache for many people. Django is pretty slow at fetching from PostgreSQL compared to other python options, so this could explain part of the 14x VS 4x difference. Note that Django should be adding an index because of ForeignKey. However it's possible it isn't being used, or the table may need to analyze stats again. Also note that Django does not support prepared statements built in, and when you don't use prepared statements you do not use the PostgreSQL query cache. Prepared statements can give a 50% speedup often, because they don't have to do the query parsing and do a n...

About a year ago I had to implement a system where the table name could be configured for an application.  Why would you want to do that?  Lots of reasons really, like if you have a table generator via a web interface.  In this case, the system integrates with other systems, and users need a way to specify where the data would go in an existing database.  So I merrily went ahead to try and put the table name in a prepared statement... but ERROR!  Unfortunately the sqlite database does not do table names or column names via prepared statements (like postgresql does for example).  The documented solution by sqlite is to escape them correctly with the provided functions.  Unfortunately python does not expose these SQL escaping functions - since most people should be using prepared statements. Here are some WONTFIX, closed, invalid bugs also mentioning table names, and column names not being a problem.  One of them is six years old. (closed wontf...