Errata for Oracle8 Design Tips

index" and "Such tables are ideal for ..." to "Such tables appear attractive at first sight for ..."

"user-defined data types (or UDTs)"

"User-defined types are known formally as abstract data types (ADTs). They can be used in ...." was changed to: "User-defined types (UDTs) can be used in ..."

changed "ADTs" to "UDTs"

... AS OBJECT { changed to: ... AS OBJECT (

MEMBER FUNCTION area RETURN NUMBER); }; changed to: MEMBER FUNCTION area RETURN NUMBER ); /

CREATE OR REPLACE TYPE BODY circle now reads: CREATE OR REPLACE TYPE BODY circle AS

Perhaps more importantly, Oracle's Object Database Designer (ODD) creates both the object views and the C++ classes to allow the application programmer to manipulate the views directly without having to master Oracle8 OCI.

option"

"trigger" to "view"

"However, if the insert has resulted in a duplicate ..." changed to: "However, if the insert would have resulted in a duplicate ..."

We would also caution that the performance of these features should be rigorously verified under realistic load conditions before relying on them in a production system. Our limited personal experience of LOBs indicates that the performance is excellent, but we have heard reports of performance problems with Oracle/AQ.

ALTER TABLE my_tab ENFORCE CONSTRAINT mt_ccl; changed to: ALTER TABLE my_tab ENABLE CONSTRAINT my_tab_xx NOVALIDATE;

every row." added new sentence: Of course without performing the checks there is no way of knowing how much bad data is present, if any.

"Of course for .... discussed in the next section" changed to: Of course for SELECT, UPDATE, and DELETE operations Oracle's query optimizer will do this for you. With predicate clause testing the partition key for equality, it will access only the correct partition; where there is a range scan, it will access only those partitions whose partition key can fall within the range. Clever stuff.

one partition ..." to "... which are entirely within a single partition or a subset of partitions."

partitioned index"

"Index", it is now labelled "Index Partition" (6 cases)

grid was labelled "Table", it is now labelled "Table Partition" (4 cases)

"For this reason ... rather than globally, partitioned." changed to: "For this reason, wherever possible you should make your unique indexes locally partitioned and you should place the partition key at the leading edge of the unique key."

Index"

" ... new type of object called an index-only table." changed to: " ... new type of object originally called an index-only table."

" ... call it an index-only table." changed to: " ... call it a table of organization index."

"Constraints cannot be defined on ... constraints." changed to: "Long columns cannot be referenced in any type of constraint."

"Oracle had continually asked ... as much as 10 megabytes." changed to: "Oracle claims that the memory consumption of Oracle8 is 20 - 30% lower than Oracle7. However, under Oracle7 most applications were using at least 1.5 Mb of server memory per connected user, and many were using considerably more. The claimed reduction in memory usage, if realized in practice, might allow some applications to run with "only" 1 Mb and might reduce the overhead of the largest applications to 3 or 4 Mb."

"If necessary, you can specify each bitmap for a combination of values from 1 to 16 columns, ..." changed to: "If necessary, you can specify up to 16 columns for the key to a bitmap index, ..."

"... lock conflicts are almost inevitable ... values updated in multi-user operation." changed to: "... lock conflicts are almost inevitable if bitmap indexes are used on tables where index updates are occurring in parallel. This means that bitmap indexes are unsuitable for use on any table subject to DML from within an online system."

"In Oracle8, you can use ...as we describe in the next section." changed to: "In Oracle8, the NOLOGGING option may be applied to any of the following: SQL*Loader Direct Path CREATE TABLE ... AS SELECT ... CREATE INDEX ... ALTER TABLE ... MOVE PARTITION ALTER TABLE ... SPLIT PARTITION ALTER INDEX ... SPLIT PARTITION ALTER INDEX ... REBUILD ALTER INDEX ... REBUILD PARTITION The operation takes place as it normally would with the exception that neither redo log nor rollback entries are created (except for any space management operations which are required). This greatly speeds up the operation for large tables, but it essentially requires that a backup be taken immediately after the operation (or set of operations) has been completed. In addition, the NOLOGGING attribute may be set on any table to permit the use of the APPEND hint described in the next section."

"direct-path INSERT" to "direct-load INSERT"

"SELECT p.proj_name , roi.days_to_break_even(p.roi) FROM projects p WHERE roi.days_to_break_even(p.roi) < 360;" changed to: "SELECT p.proj_name , project_roi.days_to_break_even(p.roi) FROM projects p WHERE project_roi.days_to_break_even(p.roi) < 360;"

"It may be that REFs will give faster navigation ... double or triple the overall size of the table." changed to: "You might expect that since a REF is essentially a pointer, it should have a performance advantage over a foreign key relationship when joining from a detail table to its master. In practice, we have found that navigating a REF takes exactly the same amount of time as navigating using a join based on a unique index. This is hardly surprising. The REF is actually supported internally via an index so that tables can be reorganized without the need to reset all the REFs to their rows. What is clear is that REFs, at 36 or 42 bytes, are larger in size than most foreign keys and that their use could easily double or even triple the overall row size of a simple detail table."

" ... described through the data dictionary." changed to " ... described through the data dictionary. In Oracle8 these are called user-defined types (UDTs)."

" ... features of ADTs in general. ..." changed to " ... features of UDTs in general. ..."

" , event_codeNUMBER NOT NULL REFERENCES event_codes" changed to " , event_code NUMBER NOT NULL REFERENCES event_codes"

" ... dateonly(trunc(sysdate));" changed to " ... dateonly(trunc(sysdate)));"

"... constructor function offers a natural ..." changed to: "... constructor function should have offered a natural ..."

Designer (ODD)"

"... for managing the user interface." changed to "... for managing the user interface, other than a simple package to generate HTML which is included with Oracle's WebServer product."

"... from Object Designer may ..." changed to: "... from Object Database Designer will ..."