WL#1121: Simplifying test data generation

Affects: Server-7.1   —   Status: Un-Assigned

Currently to create large enough set of data we have to write the scripts
etc which makes generation of test cases/bugs hard.

As soon as we get INFORMATION_SCHEMA or similar virtual system tables we shall
also add virtual table which would allow us to generate dump data (sort of

So we could for example use the following query to generate table with 
1.000.000 random values:

INSERT INTO random  select rand() from zero_source limit 1000000