共享表和共享流表之间的区别？

Question

In DolphinDB, a shared streamTable can be used in streaming subscription scenarios whereas a shared table cannot. So why do we still share the regular table ? What is it that the shared tables can do while the shared streamTables cannot?

Answer 1

Both types of shared tables can be used across sessions. A shared streamTable can be subscribed while a shared table cannot, like you said.

However, the data of a shared streamTable cannot be updated or deleted whereas shared table can. Check this:

share table(1 2 3 as id, 4 5 6 as value) as table1;
go;
update table1 set id = 7; // success
delete from table1;  // success 

share streamTable(1 2 3 as id, 4 5 6 as value) as table2;
go;
update table2 set id = 7 ; // update table2 set id = 7 => The table is not allowed to be updated.
delete from table2; // delete from table2 => It is not allowed to delete rows from the specified table.