Questions: Say I have a many to many relationship and when I query the db for the left table using a join from the right table I get duplicates because of this many to many relationship. I can use gro...
Questions: If you are going down the road of using views, how can you ensure good performance? Or is it better not to use views in the first place and just incorporate the equivalent into your select ...
Questions: I have been experimenting with Redis and MongoDB lately and it would seem that there are often cases where you would store an array of id’s in either MongoDB or Redis. I’ll stic...
Questions: I’m helping maintain a program that’s essentially a friendly read-only front-end for a big and complicated MySQL database — the program builds ad-hoc SELECT queries from u...
Questions: I am getting the following: Native table 'performance_schema'.'file_instances' has the wrong structure Native table 'performance_schema'.'cond_instances' has the wrong structure Native tabl...
Questions: We’re considering using UUID values as primary keys for our MySQL database. The data being inserted is generated from dozens, hundreds, or even thousands of remote computers and being...
Questions: What exactly does null do performance and storage (space) wise in MySQL? For example: TINYINT: 1 Byte TINYINT w/NULL 1 byte + somehow stores NULL? Answers: It depends on which storage engin...
Questions: I’m just about to write a query that includes a WHERE isok=1. As the name implies, isok is a boolean field (actually a TINYINT(1) UNSIGNED that is set to 0 or 1 as needed). Is there a...
Questions: Is there a measurable performance difference between using INT vs. VARCHAR as a primary key in MySQL? I’d like to use VARCHAR as the primary key for reference lists (think US States, ...
Questions: I am wondering if there is any difference in regards to performance between the following SELECT ... FROM ... WHERE someFIELD IN(1,2,3,4) SELECT ... FROM ... WHERE someFIELD between 0 AND 5...
