Creating Directed Queries
CREATE DIRECTED QUERY
associates an input query with a query annotated with optimizer hints. It stores the association under a unique identifier. CREATE DIRECTED QUERY
has two variants:
CREATE DIRECTED QUERY OPTIMIZER
directs the query optimizer to generate annotated SQL from the specified input query. The annotated query contains hints that the optimizer can use to recreate its current query plan for that input query.CREATE DIRECTED QUERY CUSTOM
specifies an annotated query supplied by the user. Vertica associates the annotated query with the input query specified by the lastSAVE QUERY
statement.
In both cases, Vertica associates the annotated query and input query, and registers their association in the system table V_CATALOG.DIRECTED_QUERIES
under query_name
.
The two approaches can be used together: you can use the annotated SQL that the optimizer creates as the basis for creating your own (custom) directed queries.