Projection Deletes
Posted: Mon Sep 26, 2016 7:01 am
Hello,
I need to understand how data from a projection gets deleted. Consider the below scenario with a table containing 3 columns a,b,c and there are two projections
a) Super Projection
b) User-Defined Projection with columns a and b.
If I delete from the table having the predicate as c, how will the data be removed from the user-defined projection since there is no c column ?
Ex : CREATE TABLE TEMP(A INT,B INT,C INT);
CREATE PROJECTION TEMP_SUPER
(
A,B,C ) AS SELECT A,B,C FROM TEMP;
CREATE PROJECTION TEMP_USER
(
A,B ) AS SELECT A,B FROM TEMP;
INSERT INTO TEMP(a,b,c) SELECT 1,2,3;
INSERT INTO TEMP(a,b,c) SELECT 4,5,6;
DELETE FROM TEMP WHERE C = 6;
How will data from User-defined projection TEMP_USER be removed ??
I need to understand how data from a projection gets deleted. Consider the below scenario with a table containing 3 columns a,b,c and there are two projections
a) Super Projection
b) User-Defined Projection with columns a and b.
If I delete from the table having the predicate as c, how will the data be removed from the user-defined projection since there is no c column ?
Ex : CREATE TABLE TEMP(A INT,B INT,C INT);
CREATE PROJECTION TEMP_SUPER
(
A,B,C ) AS SELECT A,B,C FROM TEMP;
CREATE PROJECTION TEMP_USER
(
A,B ) AS SELECT A,B FROM TEMP;
INSERT INTO TEMP(a,b,c) SELECT 1,2,3;
INSERT INTO TEMP(a,b,c) SELECT 4,5,6;
DELETE FROM TEMP WHERE C = 6;
How will data from User-defined projection TEMP_USER be removed ??