SQL/MP Installation and Management Guide

Managing Database Applications
HP NonStop SQL/MP Installation and Management Guide—523353-004
10-24
Using the COMPILE Option
•
COMPILE INVALID PLANS directs the SQL compiler to explicitly compile these
SQL statements:
°
Statements that refer to changed DEFINEs.
°
Statements with plans that fail the redefinition timestamp check.
°
Statements with altered execution plans. An altered execution plan is an invalid
but operable plan that the SQL compiler has updated without recompiling. For
more information, see Altered Execution Plans.
°
Uncompiled SQL statements with empty sections. The SQL compiler
generates an empty section if an SQL statement refers to a nonexistent
DEFINE or SQL object.
Other SQL statements retain their existing execution plans.
The COMPILE INVALID PLANS option stores similarity information in the program
file and updates the program’s name map and usages in the USAGES tables.
If the program has not been previously compiled or if the program does not contain
similarity information, the COMPILE INVALID PLANS option directs the SQL
compiler to compile all SQL statements in the program.
•
COMPILE INOPERABLE PLANS directs the SQL compiler to explicitly compile
these SQL statements:
°
Statements with inoperable plans (plans that fail the similarity check).
°
Uncompiled statements with empty sections. The SQL compiler generates an
empty section if an SQL statement refers to a nonexistent DEFINE or SQL
object. (The SQL compiler also generates empty sections for CONTROL
directives and DDL statements.)
Other SQL statements retain their existing execution plans.
The COMPILE INOPERABLE PLANS option stores similarity information in the
program file and updates the program’s name map and usages in the USAGES
tables.
If the program has not been previously compiled or if the program does not contain
similarity information, the COMPILE INOPERABLE PLANS option directs the SQL
compiler to compile all SQL statements in the program.
Altered Execution Plans
If you recompile a program by using the COMPILE INOPERABLE PLANS option, the
SQL compiler performs the similarity check if an SQL object refers to a changed
DEFINE or the timestamp check fails for a referenced object in the execution plan.
If the similarity check passes, the SQL compiler alters the execution plan with this new
information: