Recording a small table should be in the last multi-table query of from
Which one of from Wrom should write when writing conditions?
Write the connection between tables when WHERE conditions
SELECT word to avoid use of '*'
Try to minimize the number of access to the database
Replace Delete with truncate when deleting full table (unrecoverable)
Use Commit as much as possible
Use the alias (Alias)
Use exists to replace in (not all cases)
Use table connection to replace EXISTS
Avoid using calculations on index columns
Avoid using NOT on the index column
Use> = alternative>
Replace OR with UNION (for index columns)
Avoid using is NULL and IS NOT NULL on index columns
Avoid changing the type of index
Substitution with WHER ORDER BY
The ORDER BY clause uses an index only under two strict conditions.
All columns in ORDER BY must be included in the same index and remain in the index in the index.
There is at least one listed in Order By '
In the WHERE clause! = || operator will not use the index column name = nVL (column name) Do not use index like> Using an index
