ndb table data length

[Jon Anderson]

I've noticed some odd behavior when it comes to NDB table data length. It doesn't seem to free memory when deleting large numbers of rows (5.0.18-max-x86_64):

create database memory_test;
use memory_test;
create table memory_hog (hog_id INT AUTO_INCREMENT PRIMARY KEY,hog_data VARCHAR(255)) ENGINE=NDB;
show table status like 'memory_hog';
(Shows 0 rows, 0 avg. length, and 0 data length)

I have a PHP script that inserts 65536 rows into this table:
65536 times "insert into memory_hog (hog_data) values('<random data>');"
show table status like 'memory_hog';
(Shows 65536 rows, 276 avg length, and 19791872 data length)

276 * 65536 = 18218936 v.s. 19791872 -> That's close enough (a little overhead is fine).

delete from memory_hog limit 32768;
show table status like 'memory_hog';
(Shows 32768 rows, 276 avg length, and 19791872 data length)

276 * 32768 = 9043968 v.s. 19791872?

delete from memory_hog limit 16384;
show table status like 'memory_hog';
(Shows 16384 rows, 276 avg length, and 19791872 data length)

Same thing, deleting 1/2 the rows: 8192, 4096, 2048, 1024: Data length stays the same at 19791872. The data length finally dropped when I got down to 512 rows.

This in itself isn't a problem, but we're getting this with tables that are filled with almost 500 megs of data - when we clear out 80% of the data, the table appears to continue to use all 500 megs.

Anyone know of a way to flush that empty memory out of the table?