This chapter introduces Oracle pseudocolumns that LightDB has supported.
ORA_ROWSCN
In LightDB, ORA_ROWSCN
is equivalent to xmin
except the type of
ORA_ROWSCN
is bigint
.
Example
create table foo(a int); insert into foo values (1); select ora_rowscn, xmin from foo;
The following queries are supported:
DUAL Table
DUAL table is a virtual table provided by the system. Use when executing SQL where access to a base table is not required, such as when performing tests to get result expressions such as functions and operators.
Example
In the following example, the current system date is returned.
SELECT CURRENT_DATE "date" FROM DUAL; date ------------ 2013-05-14 (1 row)