261 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.

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.

Examples

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');

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.

UTL_RECOMP.RECOMP_PARALLEL(
   threads  IN   PLS_INTEGER DEFAULT NULL,
   schema   IN   VARCHAR2    DEFAULT NULL,
   flags    IN   PLS_INTEGER DEFAULT 0);

RECOMP_SERIAL Procedure

This procedure recompiles invalid objects in a given schema or all invalid objects in the database.

UTL_RECOMP.RECOMP_SERIAL(
   schema   IN   VARCHAR2    DEFAULT NULL,
   flags    IN   PLS_INTEGER DEFAULT 0);