Huge memory usage on INSERT INTO ... SELECT

[Adrian Partl]

We have 8e9 rows in a Spider table, distributed over 4 mysql nodes.
If we now want to copy that data from one Spider table on the head
node to another Spider table (again distributed over 4 mysql nodes)
using

INSERT INTO foo SELECT * FROM huge_spider_table

the head node will use up all memory and eventually crash.

It seams, that the Spider engine first copies all the data retrieved
by the SELECT into memory and then passes that on to the new
table.

Possible resolution:
- Stream and buffer results from the huge_spider_table to the new
one, bypassing the need to have everything in memory.

- use on disk temporary table

[Kentoku SHIBA (kentokushiba)]

Fixed at 2.28.
Please try "quick_mode = 3".