STARJOIN RESET Statement Options

The server uses RESET statements in the server SQL to provide information about and to configure the server STARJOIN settings.

RESET NOSTARJOIN=[0/1]

The NOSTARJOIN option suppresses the use of the server STARJOIN optimizer in the planning and running of SQL statements that have valid STARJOIN patterns or star schemas. When NOSTARJOIN is enabled, the server ignores STARJOIN and uses pairwise joins to plan and run SQL statements. The default setting is NOSTARJOIN=0, which means that STARJOIN is enabled, and STARJOIN optimization occurs when SQL recognizes a valid server pattern or star schema.

execute(reset nostarjoin=<1/0>)
  by sasspds ; 

NOSTARJOIN=0

enables the server STARJOIN facility.

NOSTARJOIN=1

disables the server STARJOIN facility.

Note: The statements NOSTARJOIN and NOSTARJOIN=1 are equivalent.

RESET STARMAGIC=nnn

STARMAGIC is the STARJOIN counterpart to the SQL MAGIC number option. You can use STARMAGIC options to manually adjust certain internal STARJOIN heuristics to improve certain join strategies.

The STARMAGIC option uses bit flags to configure the STARJOIN code. You can select different controls by adding the values for the bit flags below:
execute(reset starmagic=<1/2/4/8/16>)
  by sasspds ; 

STARMAGIC=1

forces all dimension tables to be classified as Phase I tables.

STARMAGIC=2

currently not used.

STARMAGIC=4

requires an exact match on the FACT composite index in order to meet Phase I conditions for STARJOIN.

STARMAGIC=8

disables the IN-SET STARJOIN strategy. The IN-SET strategy is enabled by default.

STARMAGIC=16

disables the COMPOSITE STARJOIN strategy. The COMPOSITE strategy is enabled by default.

RESET DETAILS="stj$"

The RESET DETAILS option prints details about your server STARJOIN facility settings. All internal STARJOIN debugging information is tied to the stj$ DETAILS key. You issue the stj$ reset option to display available information as the server attempts to validate a join subtree. The RESET DETAILS="stj$" option is very useful for debugging STARJOIN and SQL statement execution.

execute(reset details="stj$")
  by sasspds ;  
Last updated: February 8, 2017