Technical Notes

After every DDL operation, implicit commit occurs such as while defining a new table. e.g. CREATE TABLE HR.EXAMPLE(ABC char(1)); Also w...

BLOB (binary large objects) stores unstructured binary large objects. It is often used for graphic images, video clips, and sounds. The BLO...

CTAS stands for Create Table As Select e.g. SQL> CREATE TABLE HR.EMPLOYEES_NEW AS     SELECT * FROM HR.EMPLOYEES; -> By defau...

-> HR.EMPLOYEES will be test table. SQL>  DESC HR.EMPLOYEES; e.g. To populate all data SQL>  SELECT * FROM HR.EMPLOYEES; T...

Action SQL> ANALYZE TABLE HR.EMPLOYEES LIST CHAINED ROWS INTO CHAINED_ROWS ; Error ORA-01495 : specified chain row table not found ...

Preparation SQL> create table A (id number, soid number); SQL> create table B (id number); Action SQL>  alter table A add...

Action SQL>  CREATE TABLE HR.EXAMPLE(ABC char(1)); Error ORA-00959: tablespace '_$deleted$40$0' does not exist Reason Def...

Preparation SQL> -- A table is child table create table A (id number, soid number); SQL> -- B table is parent table create tab...

Preparation " employees " table exists in HR schema " v_employees " view exists in HR2 schema; SQL> grant select ...

Oracle SQL Developer -> Connections -> Right mouse click on desired database connection name (e.g. XE) -> Click "Open SQL Wo...

e.g. Alt key + Print Screen  key -> Then CTRL + V in "mspaint.exe" -> Save it.

e.g. If there are only 32 bit Linux distro in the OS list, you should enable virtualization support in BIOS * BIOS -> CMOS Setup Utilit...

SET TIMING ON / CREATE TABLE HR.EMPLOYEES_TEST AS    SELECT *      FROM HR.EMPLOYEES     WHERE ROWNUM < 0; / DECLARE    TYPE TAB...

You may use following free tool instead of Oracle EM (Enterprise Manager) ASH Viewer (Active Session History)

index -> [ SHORT_TABLE_NAME ]_[ SHORT_COLUMN_NAME ]_[ INDEX_TYPE ] e.g. EMP_DEPARTMENT_IX constraint -> [ SHORT_TABLE_NAME ]_[ SHOR...

e.g. Toad for Oracle -> Database -> Schema Browser -> Click HR -> Click Procedures -> Double click to "PROC_EXEC" ...

e.g. Toad for Oracle -> Type HR.EMPLOYEES then Press F4 in Editor -> Select desired columns by CTRL key-> Drag and drop to Editor...

Purpose The purpose of optimizer_index_cost_adj parameter is to force use index even the cost is high. (decides large-table full-table scan...

e.g. steps; lock table -> add new column for primary key -> update data with counter -> define sequence -> define trigger -...

e.g. Toad for Oracle -> Help -> Contents -> Search "Debugging a Procedure or Function Tutorial"