2.309 PLSQL_OPTIMIZE_LEVEL
PLSQL_OPTIMIZE_LEVEL
specifies the optimization level that will be used to compile PL/SQL library units. The higher the setting of this parameter, the more effort the compiler makes to optimize PL/SQL library units.
Property | Description |
---|---|
Parameter type |
Integer |
Default value |
|
Modifiable |
|
Modifiable in a PDB |
Yes |
Range of values |
|
Basic |
No |
Values
-
0
Maintains the evaluation order and hence the pattern of side effects, exceptions, and package initializations of Oracle9i and earlier releases. Also removes the new semantic identity of
BINARY_INTEGER
andPLS_INTEGER
and restores the earlier rules for the evaluation of integer expressions. Although code will run somewhat faster than it did in Oracle9i, use of level 0 will forfeit most of the performance gains of PL/SQL in Oracle Database 10g. -
1
Applies a wide range of optimizations to PL/SQL programs including the elimination of unnecessary computations and exceptions, but generally does not move source code out of its original source order.
-
2
Applies a wide range of modern optimization techniques beyond those of level 1 including changes which may move source code relatively far from its original location.
-
3
Applies a wide range of optimization techniques beyond those of level 2, automatically including techniques not specifically requested.
Generally, setting this parameter to 2
pays off in better execution performance. If, however, the compiler runs slowly on a particular source module or if optimization does not make sense for some reason (for example, during rapid turnaround development), then setting this parameter to 1
will result in almost as good a compilation with less use of compile-time resources.
The value of this parameter is stored persistently with the library unit.
See Also:
-
Oracle Database PL/SQL Language Reference for more information about this parameter
-
Oracle Database Development Guide for an example of using this parameter