SQL is the leading language for developing and querying databases, but it has a few quirks. In my last article, I shared 7 SQL mistakes to avoid. Now, let’s take a look at 9 best practices for writing faster SQL queries.
Retrieve only the columns you need
Use CASE instead of UPDATE for conditional column updates
Keep large-table queries to a minimum
Pre-stage your data
Perform deletes and updates in batches
Use temp tables to improve cursor performance
Use table-valued functions over scalar functions
Use partitioning to avoid large data moves
Use stored procedures for performance, use ORMs for convenience
A common SQL habit is to use SELECT * on a query, because it’s tedious to list all the columns you need. Plus, sometimes those columns may change over time, so why not just do things the easy way?
