295 UTL_RECOMP
The UTL_RECOMP package recompiles invalid PL/SQL modules, invalid views, Java classes, indextypes and operators in a database, either sequentially or in parallel.
This chapter contains the following topics:
295.1 UTL_RECOMP Overview
This script is particularly useful after a major-version upgrade that typically invalidates all PL/SQL and Java objects. Although invalid objects are recompiled automatically on use, it is useful to run this script prior to operation because this will either eliminate or minimize subsequent latencies due to on-demand automatic recompilation at runtime.
Parallel recompilation can exploit multiple CPUs to reduce the time taken to recompile invalid objects. The degree of parallelism is specified by the first argument to RECOMP_PARALLEL Procedure.
In general, a parallelism setting of one thread for each available CPU provides a good initial setting. However, please note that the process of recompiling an invalid object writes a significant amount of data to system tables and is fairly I/O intensive. A slow disk system may be a significant bottleneck and limit speedups available from a higher degree of parallelism.
295.2 UTL_RECOMP Operational Notes
UTL_RECOMP
has several operational notes.
-
This package uses the job queue for parallel recompilation.
-
This package must be run using
SQL*PLUS
. -
You must be connected
AS
SYSDBA
to run this script. -
This package expects the following packages to have been created with VALID status:
-
STANDARD
(standard
.sql
) -
DBMS_STANDARD
(dbmsstdx
.sql
) -
DBMS_JOB
(dbmsjob
.sql
) -
DBMS_RANDOM (dbmsrand.sql)
-
-
There should be no other DDL on the database while running entries in this package. Not following this recommendation may lead to deadlocks.
295.3 UTL_RECOMP Examples
These examples show various ways that UTL_RECOMP
can recompile objects.
-
Recompile all objects sequentially:
EXECUTE UTL_RECOMP.RECOMP_SERIAL();
-
Recompile objects in schema
SCOTT
sequentially:EXECUTE UTL_RECOMP.RECOMP_SERIAL('SCOTT');
-
Recompile all objects using 4 parallel threads:
EXECUTE UTL_RECOMP.RECOMP_PARALLEL(4);
-
Recompile objects in schema JOE using the number of threads specified in the parameter
JOB_QUEUE_PROCESSES
:EXECUTE UTL_RECOMP.RECOMP_PARALLEL(NULL, 'JOE');
295.4 Summary of UTL_RECOMP Subprograms
This table lists the UTL_RECOMP
subprograms and briefly describes them.
Table 295-1 UTL_RECOMP Package Subprograms
Subprogram | Description |
---|---|
Recompiles invalid objects in a given schema, or all invalid objects in the database, in parallel |
|
Recompiles invalid objects in a given schema or all invalid objects in the database |
295.4.1 RECOMP_PARALLEL Procedure
This procedure uses the information exposed in the DBA_Dependencies
view to recompile invalid objects in the database, or in a given schema, in parallel.
Syntax
UTL_RECOMP.RECOMP_PARALLEL( threads IN PLS_INTEGER DEFAULT NULL, schema IN VARCHAR2 DEFAULT NULL, flags IN PLS_INTEGER DEFAULT 0);
Parameters
Table 295-2 RECOMP_PARALLEL Procedure Parameters
Parameter | Description |
---|---|
|
The number of recompile threads to run in parallel. If |
|
The schema in which to recompile invalid objects. If |
|
Flag values are intended for internal testing and diagnosability only. |
Usage Notes
The UTL_RECOMP_COMPILED
table is updated with objects that
RECOMP_PARALLEL
has attempted to compile, or that it has compiled so
far. If you monitor the progress of the recompilation, then the number of objects should
increase with time. These tables are used internally by RECOMP_PARALLEL
to prevent an object from being compiled more than once.
Table 295-3 Tables Generated by UTL_RECOMP.RECOMP_PARALLEL
Table | Purpose |
---|---|
|
A table of objects that are sorted into groups, based on dependencies. It
is used internally by |
|
A table of objects that |
|
An index created on |
|
A table of objects that |
Table 295-4 Views Generated by UTL_RECOMP.RECOMP_PARALLEL
View | Purpose |
---|---|
|
A view that includes all objects that can be compiled. |
|
A view that selects invalid objects from
|
|
A view that selects objects from |
|
A view that selects objects from |
|
A view that selects from
|
|
A view that selects from |
|
A view that selects from |
|
A view that includes all stub objects that have not been
compiled, and are not on the skip list. When this view is used in
|
295.4.2 RECOMP_SERIAL Procedure
This procedure recompiles invalid objects in a given schema or all invalid objects in the database.
Syntax
UTL_RECOMP.RECOMP_SERIAL( schema IN VARCHAR2 DEFAULT NULL, flags IN PLS_INTEGER DEFAULT 0);
Parameters
Table 295-5 RECOMP_SERIAL Procedure Parameters
Parameter | Description |
---|---|
|
The schema in which to recompile invalid objects. If |
|
Flag values are intended for internal testing and diagnosability only. |