Understanding predicates in SQL statements
A predicate is an element of SQL that is used for search operations. These are specified in the WHERE and the HAVING clause. Every database has its own set of predicates, which are used to filter the table data. There are different types of predicates in DB2, and DB2 has its own way of evaluating them. Based on the cost and the efficiency of a predicate, we can classify them as follows:
- Range delimiting predicates
- Index SARGable predicates
- Data SARGable predicates
- Residual predicates
Note
SARGable is a term used for Search Argument
In this recipe, we will discuss these predicates, and analyze their impact on query performance.
Getting ready
All the examples used in this recipe use the tables in the SAMPLE database. ...
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