What is the significance of ACCESSTYPE and INDEXONLY column of a PLAN table in DB2?

The PLAN_TABLE in DB2 contains details of the access paths used by the optimizer from the EXPLAIN statement. This table gives much information about the PLAN having DB2 SQL statements.

ACCESSTYPE is one of the columns of PLAN_TABLE which gives details regarding the access type. The values which can be present in this column and its interpretation is given below.

Column value
Indexed access
Tablespace scan
Multiple index scan
Index access present in predicate

The INDEXONLY column can take the value as ‘Y’ which indicates that the optimizer just needs to read indexspace in order to fetch the data for the query.