Similarities and differences between oracle and db2

Some similarities and differences between oracle and db2 1. Differences between Table space for indexes Oralce: Create TABLE T1 ............. IN DATA_TACreate Index ........ ON T1 ...... IN INDX_TS DB2: Create TABLE T1 ........ IN DATA_TS index in INDX_TSCreate INDEX ..... ON T1 www.2cto.com 2, RowID Oracle: Oracle has RowID, which is uniquely generated by the database. In the program, the corresponding value of DB2: DB2 cannot be obtained by the program. 3, some Oracle conversions: Oracle supports some conversions, such as: Create table t1 (c1 int); Select * from t1 where c1 = '1' Select 'abc' | 2 from t1 DB2: DB2 does not support some conversions, such AS: Create table t1 (c1 int); Select * from t1 where c1 = CAST ('1' as int) select 'abc' | CHAR (2) from t14, the function value is used as the default value in the table Oracle: Oracle supports using the function value as the default value In the table, for example: create table t1 (C1 Number default fn () not null, C2 date default not null sysdate) DB2: DB2 does NOT support using the function value as the DEFAULT value In the table, for example: create table t1 (C1 int not null, C2 timestamp default current timestamp) This is NOT allowed for 5, some built-in functions expect () CHAR (), INTEGER (), TO_CHAR () TO_DATE () CHAR (date, FN) TO_DATE () 6, Public Synonyms (Public Synonyms) Oracle: Oracle supports Public Synonyms DB2: DB2 does not support Public Synonyms 7, date/TimeOracleDB2SYSDATECURRENT DATECURRENT TIMESTAMPDT1 + 2Add_months (DT1, 5) DT1 + 2daysDT2 + 5monthsDT1 + values (k, Char (TS1-TS2) To_date (DT1, 'Mm/DD/YYYY ') char (DT1, USA) Char (TM1, ISO) 8, external connection OracleDB2Select. lastname, A_id, B. name From emp A, Customer Bwhere. id (+) = B. sales_rep_id; Select. lastname, A_id, B. name From emp A, right outer join Customer Bwhere. id = B. sales_rep_id; Select. lastname, A_id, B. name From emp A, Customer Bwhere. id = B. sales_rep_id (+); Select. lastname, A_id, B. name From emp A, left outer join Customer Bwhere. id = B. sales_rep_id; Select. lastname, A_id, B. name From emp A, Customer Bwhere. id (+) = B. sales_rep_id (+); Select. lastname, A_id, B. name From emp A, Full outer join Customer Bwhere. id = B. sales_rep_id; currently, Oracle 9i also supports this ANSI join syntax
9. Merge string and null Select 'abc' | c1 from T1C1 is nullResult: Oracle: abc DB2: null to get 'abc ', in DB2, Select 'abc' | coalesce (c1, '') from T1