The + tells oracle that this isn't an ordinary comment, that it is in fact a hint no spaces are allowed between the comment delimiter and the plus. Oracle has many hints to choose from know what they are and how they are different from one another before tossing them into production.
Part one of christo kutrovsky's new series on oracle parallel query hints. Universal hint system hints for the jewels of the oracle the uhs shows you just the hints you need, unlike a traditional walkthrough.
In various sql implementations, a hint is an addition to the sql standard that instructs the oracle implements hints by using specially-crafted comments in the query that begin with a + symbol, thus not affecting sql compatibility postgres. Oracle hints are enclosed within comments to the sql commands delete, select or update or are designated by two dashes and a plus sign to show the.
Note: the demos on this page are intended to show valid syntax but it is far easier to use a hint to make a mess of things than it is to improve things so many , if. Oracle tuning with hints oracle ensures that the cost-based sql optimizer becomes more sophisticated with each release with each new release, oracle.
These two points could leave data logically corrupt, so oracle ignores the append hint and the data is loaded using conventional path if enabled referential.
- Alternatively, don't mess about with the indexes – just tell oracle to push the predicate normally i would just try /+ push_pred(v1) / as the hint.
Home using tuning dbms hints oracle hints category hint available for notes acc path and_equal /+ cluster ( tablespec ) . Hints let you make decisions usually made by the optimizer as an application designer, you might know information about your data that the optimizer does not . Oracle ace ami aharonovich: new optimizer hint: append_values for improving insert performance.