Forum: Building VoltDB Clients

Post: Error: More than 100 MB of temp table memory used

Error: More than 100 MB of temp table memory used
João Saraiva
May 9, 2012
Hello,
I'm trying to make a benchmark with TPC-H for a college project.
I have already insert the tables in the database successfully, but now I'm having problems with the queries.

This is the querie 1 of TPC-H. I've done some changes to run on voltdb, but it returns the error of More than 100 Mb of temp table memory used..
select
l_returnflag,
l_linestatus,
sum(l_quantity) as sum_qty,
sum(l_extendedprice) as sum_base_price,
sum(l_extendedprice * (1 - l_discount)) as sum_disc_price,
sum(l_extendedprice * (1 - l_discount) * (1 + l_tax)) as sum_charge,
avg(l_quantity) as avg_qty,
avg(l_extendedprice) as avg_price,
avg(l_discount) as avg_disc,
count(*) as count_order
from
lineitem
where
l_shipdate <= '1998-12-01'
group by
l_returnflag,
l_linestatus
order by
l_returnflag,
l_linestatus;
Can someone help me please?
Overflowing temp table space
rbetts
May 11, 2012
Overflowing temp table space means you are materializing a lot of data. One common reason for materializing too much data is writing a multi-partition/distributed select that tries to return the entire database to the coordinating partition.
We currently don't distribute AVG. If the above query is not run in a single-partition parameter, this is possibly the cause of your problems. It's my best guess without seeing more of your application.
Curious to hear more about your project. I apologize for the delay in answering your forum question. Let us know how it's going.