SQL queries are commands that WordPress uses to retrieve the data. It is the base for your WordPress site: it keeps all the data and manages the queries to load it. WordPress works with relational databases: those that consist of tables interrelated with each other. That’s why you need to make checking its performance your habit. Naturally, if there’s an issue with your database, it can result in some sensible trouble for your entire site. This database management system stores and handles all data from your WordPress site. These two are not to be confused: SQL (a language) is the means of communicating with MySQL (a database management system). It got its name from the language used for the queries – SQL, or search query language. It is one of the most widely implemented software used for handling lots of tables of data. This is a database management system used in WordPress. If you’d rather skip right to the MySQL database tuning, click here to jump to the most interesting part. Ticket tracker Report bugs with Django or Django documentation in our ticket tracker.In case you’re not familiar with it, we’ll tell you in a few words. Official Django Forum Join the community on the Django Forum. Django Discord Server Join the Django Discord Community. #django IRC channel Ask a question in the #django IRC channel, or search the IRC logs to see if it’s been asked before. django-users mailing list Search for information in the archives of the django-users mailing list, or post a question. Index, Module Index, or Table of Contents Handy when looking for specific information. Getting help FAQ Try the FAQ - it's got answers to many common questions. Don’t overuse contains(), count(), and exists().Use QuerySet.values() and values_list(). Use lect_related() and prefetch_related().Retrieve everything at once if you know you will need it.Retrieve individual objects using a unique, indexed column.Do database work in the database rather than in Python.Use standard DB optimization techniques.Or unt() for the count would each cause additional queries.Ĭarlos Joel donated to the Django Software Foundation to QuerySet.exists() for the if, ntains() for the in, The onlyĭeliberate optimization performed is using the members variable. In total, this code does either one or zero database queries. The for member loop iterates over the result cache.The use of len(members) calls QuerySet._len_(), reusing the resultĬache, so again, no database queries are issued.The line if current_user in members: checks if the user is in the resultĬache, so no additional database queries are issued.If thereĪren’t any results, it will return False, otherwise True. The line if members: causes QuerySet._bool_() to be called, whichĬauses the () query to be run on the database. Storing () in the members variable allows its.Since QuerySets are lazy, this does no database queries if.username ) else : print ( "There are no members in this group." ) all () if display_group_members : if members : if current_user in members : print ( "You and", len ( members ) - 1, "other users are members of this group." ) else : print ( "There are", len ( members ), "members in this group." ) for member in members : print ( member. That in your circumstances the general principle might not apply, or might even All of the suggestions below come with the caveat That the change is a benefit, and a big enough benefit given the decrease in With everything that follows, remember to profile after every change to ensure Since this will depend on your application and server. Priorities are, where the balance must lie, and profile all of these as required Also, work that is done by theĭatabase process might not have the same cost (to you) as the same amount of Other, but sometimes they will help each other. Sometimes optimizing for one will be detrimental to the Remember that you may be optimizing for speed or memory or both, depending on You may also want to use an external project likeĭjango-debug-toolbar, or a tool that monitors your database directly. Use QuerySet.explain() to understand how specific QuerySets areĮxecuted by your database. Queries you are doing and what they are costing you. As general programming practice, this goes without saying.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |