Support temporary table

[zimulala]

1. What did you do?
   create temporary table t1( n int);

2.What did you expect to see?
Query OK, 0 rows affected (0.00 sec)

3.What did you see instead?
ERROR 1105 (HY000): line 1 column 8 near "temporary"

It can refer to MySQL Doc

[zimulala]

Currently, we only support syntax, there is no real support for temporary table.

[zz-jason]

One use case in the batch process:

create a temporary table in each session:

create temporary table tmp(a bigint, b bigint);

concurrently execute the following transaction:

begin;

-- clear the tmp table.
truncate table tmp;

-- fill the tmp table.
insert into tmp select a, b from t where <condition> order by <primary_key> limit <batch_size> for update;

-- some select queries on the tmp table.
select ...

-- update the base table based on the same condition, the order by clause ensures the same batch.
update t set <change_some_status_field> where <condition> order by <primary_key> limit <batch_size>;

commit; -- or rollback.