• Reference parameters (inout and out) are faster then value parameters (in).

  • Use cursors and positioned delete/update (where current of) for read-modify transactions instead of a select .. into and searched update.

  • Make an EXCLUSIVE read in read-modify transactions.

  • When using ORDER BY and wishing to use a particular index, specify ALL key parts of the index, including those that have a '=' condition. If you want to have descending order using an index, specify DESC on ALL key parts.