I have a query in the following format: select id from table1 group by id having count(id) < 2;
table1 is a log table that gets written to by a trigger. We run a monitor every 2 hours and the query above is what the monitor executes. In about a week, the table has grown to approximately 100,000 rows.
I am debating whether an index is necessary on the table? On one hand, I am thinking since this table is written to a lot, I want the least overhead possible. On the other hand, i'm thinking if it is worth indexing on the ID column for a monitor that runs every 2 hours? For now, the monitor takes about 80 milliseconds to execute.
Can you give me some advice on what my best steps should be? Thank you