1. (Middle) Save a 100,000
sized generated random table in problem 4 as a splayed table below
a directory called splaydir
https://code.kx.com/trac/wiki/Cookbook/SplayedTables
using the single step approach.
	q genandsplay.q
	q ./splaydir

2. (Middle) Left joins are equi-joins on key fields but not foreign keys.
https://code.kx.com/trac/wiki/Reference/lj
The foregin key table on the right dominates on any common columns.
Join the address and coolness tables based on stock name.
	q equijoin.q

3. (Middle) There are two markets with different trades. We want
to find the pairs of trades that occur at the same time.
So these are equi-joins on an ascending field.
https://code.kx.com/trac/wiki/Reference/aj
All trades take place between 10 AM and 10:01 AM.
	q asofjoin.q

4. (Middle) There are two markets with trades on various symbols. We want
to find the price and amounts of the trades on the same symbols
in the two markets with the following semantics.
For each trade x1 from the first market and include x2 from the second market
if both x1 and x2 pertain to the same symbol and either
x2 and x1 occur within one second of one another or if there is no trade
on symbol s within one second prior to x1 and x2 is the last trade on s in the
second market before time t.
All trades take place between 10 AM and 10:01 AM.
Use the wj primitive.
https://code.kx.com/trac/wiki/Reference/wj

	q windowjoin.q
5. (Middle) Do a query similar to the previous one, but
for each x1 include all x2s such that x1 and x2 share the same symbols
and x2 is within 10 seconds of x1.
In this case, use a user-defined function.
	q windowjoinprecise.q

