Question

I have compsite index on three fields that is NErrorCode, TmeRun and DteRun in a table with name as AURORATASKS_STATUS having index position 1, 2, 3 repectively. Now i want to change the position of DteRun to 1. How i will write a SQL statement for this?

Answer 1

Drop the existing index, and create a new one.

Standard SQL for dropping an index is

DROP INDEX indexname;

And adding a new one

CREATE INDEX indexname ON tablename (DteRun, NErrorCode, TmeRun);

or

CREATE INDEX indexname ON tablename (DteRun, TmeRun, NErrorCode);

Most modern dbms have a relatively large number of options for creating indexes. It’s probably worth reading about them before you try this.