SAP Basis Tech Supports

Symptom
You observe very long import runtimes in systems with a large db_cache_size. Runtime measurements show that:
- The import lasts approximately 6 hours when the db_cache_size is 2 GB.
- The import lasts approximately 10 hours when the db_cache_size is 5 GB.
- The import lasts approximately 30 hours when the db_cache_size is 20 GB.
You observed these long import runtimes in Oracle Releases 9.2.0.7, 9.2.0.8 and 10.2.0.2 if you imported tables with LONG RAW columns.
Other terms
Import, runtime, performance, 9.2.0.7, 9.2.0.8, 10.2.0.2, db_cache_size
Reason and Prerequisites
This problem is Oracle bug number 5530958.
Important:
This problem is not always visible. It is entirely possible that one table with a LONG RAW column is imported very quickly while another is imported very slowly.
This problem only occurs if the buffer cache size of the database (either db_block_buffers or db_cache_size) is set to a value greater than 5 GB.
Solution
The bug is corrected as of Oracle Release 10.2.0.4.
For Oracle Release 9.2.0.8 and 10.2.0.2, install the bug fix that is relevant for your platform. The bug fixes are available on SAP Service Marketplace in the software center at:
http://service.sap.com/swcenter-3pmain
in the following directories:
Oracle 9.2.0.8.
AIX 5L with Oracle 64 bit
/Oracle/Oracle 64-bit/Oracle 9.2.0. 64-bit/Oracle 9.2.0.8. 64-bit/
AIX_5L_64/p5530958_92080_AIX64-5L.zip
HP-UX PA-RISC 64-bit
/Oracle/Oracle 64-bit/Oracle 9.2.0. 64-bit/Oracle 9.2.0.8 64-bit/
HP_UX_64/p5530958_92080_HP64.zip
HP UX Itanium 64-bit
/Oracle/Oracle 64-bit/Oracle 9.2.0. 64-bit/Oracle 9.2.0.8 64-bit/
HP_IA_64/p5530958_92080_HPUX-IA64.zip
HP TRU64
/Oracle/Oracle 64-bit/Oracle 9.2.0. 64-bit/Oracle 9.2.0.8 64-bit/
HP_TRU64/p5530958_92080_TRU64.zip
Linux x86-64
/Oracle/Oracle 64-bit/Oracle 9.2.0. 64-bit/Oracle 9.2.0.8 64-bit/
Linux_x86_64/p5530958_92080_Linux-x86-64.zip
LINUX 32-bit
/Oracle/Oracle 32-bit/Oracle 9.2.0. 32-bit/Oracle 9.2.0.8. 32-bit/
Linux/p5530958_92080_LINUX.zip
LINUX Itanium 64-bit
/Oracle/Oracle 64-bit/Oracle 9.2.0. 64-bit/Oracle 9.2.0.8. 64-bit/
Linux_IA_64/p5530958_92080_Linux-IA64.zip
SUN Solaris 64-bit
/Oracle/Oracle 64-bit/Oracle 9.2.0. 64-bit/Oracle 9.2.0.8 64-bit/
SOLARIS_64/p5530958_92080_SOLARIS64.zip
Windows 32-bit/Windows 64-bit (Windows 2003)
The fix is available as of Patch 5 for Oracle 9.2.0.8.
For availability, see Note 539921.
This note will be updated accordingly as soon as the patches for the platforms that are still missing are made available.

Oracle 10.2.0.2
AIX 5L 64-bit
/Oracle/Oracle 64-Bit/Oracle 10.2.0. 64-bit/Oracle 10.2.0.2/
AIX_5L_64/p5530958_10202_AIX64-5L.zip
Linux x86-64
/Oracle/Oracle 64-Bit/Oracle 10.2.0. 64-bit/Oracle 10.2.0.2/
Linux_x86_64/p5530958_10202_Linux-x86-64.zip
Linux 32-bit
/Oracle/Oracle 32-bit/Oracle 10.2.0. 32-bit/Oracle 10.2.0.2/
Linux_32/p5530958_10202_LINUX.zip
LINUX Itanium 64
/Oracle/Oracle 64-bit/Oracle 10.2.0. 64-bit/Oracle 10.2.0.2/
LINUX_IA_64/p5530958_10202_LINUX-IA64.zip
LINUX IBMPower 64-bit
/Oracle/Oracle 64-bit/Oracle 10.2.0. 64-bit/Oracle 10.2.0.2/
Linux_ppc_64/p5530958_10202_IBMPower.zip
HP-UX PA-RISC 64-bit
/Oracle/Oracle 64-bit/Oracle 10.2.0. 64-bit/Oracle 10.2.0.2/
HP-UX_64/p5530958_10202_HP64.zip
HP UX Itanium 64-bit
/Oracle/Oracle 64-bit/Oracle 10.2.0. 64-bit/Oracle 10.2.0.2/
HP_IA_64/p5530958_10202_HPUX-IA64.zip
HP TRU64
/Oracle/Oracle 64-bit/Oracle 10.2.0. 64-bit/Oracle 10.2.0.2/
HP_TRU64/p5530958_10202_TRU64.zip
SUN Solaris 64-bit
/Oracle/Oracle 64-Bit/Oracle 10.2.0. 64-bit/Oracle 10.2.0.2/
Solaris_SPARC_64/p5530958_10202_SOLARIS64.zip
SUN Solaris x86-64
/Oracle/Oracle 64-Bit/Oracle 10.2.0. 64-bit/Oracle 10.2.0.2/
Solaris_x86_64/p5530958_10202_Solaris86-64.zip
Windows 32-bit / 64-bit (Windows IA64 / x86-64)
Patch 5530958 is available for Oracle 10.2.0.2 as of patch 15.
For availability, see Note 871735.

Workaround:
For as long as there is no patch available for your release or platform, we recommend that you set the buffer cache size of the Oracle database in the reorganization to a MAXIMUM of 5 GB, if a table with a LONG RAW column is included.
You can achieve optimal performance by setting it to a value of between 1 GB and 3 GB (only in tables that contain LONG RAW columns).