| Semantics |
| Informix |
Oracle |
| Logical logs |
Redo logs |
| Physical log |
Rollback segment
Undo |
| chunk |
datafile |
| dbspace or dbslice |
tablespace |
| rootdbs |
system tablespace |
| extent |
extent |
| blob |
blob |
| Shared Memory |
SGA |
BEGIN WORK
MODE ANSI |
Always in the equivalent of MODE ANSI |
| SysMaster |
Catalog
Data Dictionary |
| INTO TEMP Clause |
CREATE TABLE <table_name> AS
SELECT ... |
Fragment |
Partition |
| Now Rowid In Fragment Table |
All Rows Have A Rowid |
| Numeric Rowid |
Non Numeric Rowid |
| Index Maps Rowid To A Physical Location |
Rowid Is A Physical Location |
| Disk Page |
Block |
| Locks |
Blocks (Disk Page) Not Lockable
Indexes Not Lockable |
| DATABASE <database_name> EXCLUSIVE |
STARTUP RESTRICT |
| Set Transaction Read Uncommited |
Dirty Read Is Impossible |
| Extended Data Types |
Types |
| Serial Data Type |
Sequence ... but an independent object
identical to DB2 implementation |
| CHAR datatype 32K |
Char datatype 4K |
| NUMBER (up to 32 digits) |
NUMBER (up to 38 digits) |
| Boolean True/False have literal
representation |
Booleans have no literal representation |
| VARCHAR datatype 255 bytes |
VARCHAR2 datatype 4K |
| CLOB |
CLOB up to 4GB |
| CLOB not stored in the row |
CLOB stored in or out of row |
| USER |
USER |
| CURRENT |
SYSDATE |
| DB_LOCALE |
Character Set
National Character Set |
Logging:
No Logging
Unbuffered Logging
Buffered Logging |
Logging:
Not possible
Not possible
Oracle |
| Round Robin |
Hash Partition |
| Fragment By Expression |
Range Partition |
| The three levels of database privilege
(Connect, Resource, and DBA) provide an overall means of controlling who accesses a
database. |
No equivalent ... these are sample roles |
Table Level Privileges:
Select
Insert
Delete
Update |
Table Level Privileges:
Select
Insert
Delete
Update
Reference
|
| Execute Privilege |
Execute Privilege |
| Roles |
Roles - similar functionality |
| View can not contain UNION or ORDER BY |
Any SQL Statement Allowed |
| View no modification if > 1 table |
Modify anything if key preserved |
| Triggers Before & After |
Available, but must be separate triggers |
| Triggers Statement * Row Level Mixed |
Statement & Row Level Separate |
| Table triggers only |
|
| ORDER BY in View not possible |
ORDER BY in Views |
| ONBAR and ONTAPE |
RMAN |
| No lock escalation |
No lock escalation |
| DECODE |
DECODE |
| UNIQUE |
UNIQUE |
Free