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Home -> Community -> Mailing Lists -> Oracle-L -> Re: Specifying "RETENTION" in 9iR2 LOB segment still uses PCTVERSION?
Hi Rich,
I am no LOB expert but I believe there is a related bug 4231990 which hasn't been updated since Mar 2005.
Regards,
Fairlie
"Jesse, Rich" <Rich.Jesse_at_qg.com> wrote: Hey all,
According to a LOB perftuning paper from Oracle, specifying RETENTION is preferred over PCTVERSION for creating LOBs when using automatic UNDO. In 9.2.0.5.0, a dev here has created a table whose subset of columns is this:
CREATE TABLE CALL_INFORMATION
(
S_CALL_ID VARCHAR2(20) NULL, S_CUSTOMERNO VARCHAR2(6) NULL, S_MACHINE_NO VARCHAR2(20) NULL, S_CALL_DESCRIPTION CLOB NULL
Notice the "RETENTION" keyword in there? But when the DDL is grabbed:
SELECT dbms_metadata.get_ddl('TABLE', 'CALL_INFORMATION') FROM dual;
The RETENTION is ignored and PCTVERSION is used:
...LOB ("S_CALL_DESCRIPTION") STORE AS ( TABLESPACE "QT_SMALL" ENABLE STORAGE IN ROW CHUNK 8192 PCTVERSION 10 CACHE... Huh? DBA_LOBS shows both PCTVERSION of 10 and a RETENTION equal to the current value of the UNDO_RETENTION parameter. I even tested:
ALTER TABLE CALL_INFORMATION modify lob(S_CALL_DESCRIPTION) (retention);
...to no avail. Is this a bug? I altered the running system's UNDO_RETENTION and noticed that DBMS_LOB's PCTVERSION still remained at 10 while the RETENTION correctly adjusted to the new value.
I couldn't find anything about this on MetaLink and Google searches were too generic to be of use.
Thoughts?
Rich
-- http://www.freelists.org/webpage/oracle-l Fairlie Rego Senior Oracle Consultant http://el-caro.blogspot.com/ __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com -- http://www.freelists.org/webpage/oracle-lReceived on Sat Jun 10 2006 - 05:59:33 CDT
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