如何使用oracle数据库提供数据并发？

Question

I have a situation where I have a oracle database table which is available to end users for reporting purposes (only select queries). This is a fully replaced table and everyday when the data arrives I have to truncate the entire table and load it again with the new data. While I do this I want my table to be always available for the reporting. But I dont want to make a copy of this table to achieve this.

Answer 1

You can DELETE and INSERT as much as you want within a single transaction, and no readers will know the difference until the final COMMIT . You can use a PL/SQL block like this to group the statements, and roll back the changes if there are any errors.

begin
    delete from mytable1;
    insert into mytable1 select ...;

    delete from mytable2;
    insert into mytable2 select ...;

    ...


    commit;

exception when others then
    rollback;
    raise;
end;
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