4 ms·
What does "poor queries" mean other than queries with poor asymptotic complexity based on the query plan?
by yuliyp 13y ago
What does "poor queries" mean other than queries with poor asymptotic complexity based on the query plan?
- boyter 13y agoDoing something like the following would classify as a poor query in my book with a very simple query plan, select * from table;
- yuliyp 13y agoThe query plan for that is simple, but the number of bytes transmitted per query is O(size of table) (as is the disk IO on the DB), which should clearly set off a red flag if you know that size of table can get large. You don't need a large exponent; You need to understand the rough cardinality of values, then you need to look at asymptotic complexity.