sqlalchemy.sql.selectable.HasHints

Add an indexing or other executional context hint for the given selectable to this _expression.Select or other selectable object.

The text of the hint is rendered in the appropriate location for the database backend in use, relative to the given _schema.Table or _expression.Alias passed as the selectable argument. The dialect implementation typically uses Python string substitution syntax with the token %(name)s to render the name of the table or alias. E.g. when using Oracle, the following:

select(mytable).\
    with_hint(mytable, "index(%(name)s ix_mytable)")

Would render SQL as:

select /*+ index(mytable ix_mytable) */ ... from mytable

The dialect_name option will limit the rendering of a particular hint to a particular backend. Such as, to add hints for both Oracle and Sybase simultaneously:

select(mytable).\
    with_hint(mytable, "index(%(name)s ix_mytable)", 'oracle').\
    with_hint(mytable, "WITH INDEX ix_mytable", 'sybase')

Add a statement hint to this _expression.Select or other selectable object.

This method is similar to _expression.Select.with_hint except that it does not require an individual table, and instead applies to the statement as a whole.

Hints here are specific to the backend database and may include directives such as isolation levels, file directives, fetch directives, etc.