With any language, the more you tell the compiler information it doesn't know the better. Want to create an list of a million items but the default constructor

With any language, the more you tell the compiler information it doesn't know the better. Want to create an list of a million items but the default constructor is 50, have to tell the compiler. Same with SQL. I know X is a great start to a filter since it's unique in this one use case I'm working on, for everything else us the stats for the column. SQL has a huge number of ways to read the data, and rewritting the sql query is reprogramming how your code reads and writes data from memory/disk. Every language has the same exact problem.