SQL optimizing large or query - mysql

Question

I'm attempting to run a query to find any matches between multiple phone number columns on two tables and it is taking far too long (>5 minutes) and this is with the data filtered as much as possible. I've separated the actual columns I can search from both tables into their own tables, just to reduce the amount of total rows.
This is from a legacy application I inherited.
Query
select count(b.bid)
from customers_with_phone c,buyers_orders_with_phone b
where
(b.hphone=c.pprim or b.hphone=c.phome or b.hphone=c.pwork or b.hphone=c.pother)
or (b.wphone=c.pprim or b.wphone=c.phome or b.wphone=c.pwork or b.wphone=c.pother)
or (b.cphone=c.pprim or b.cphone=c.phome or b.cphone=c.pwork or b.cphone=c.pother)
group by b.bid;
Tables
mysql> show columns from customers_with_phone;
+--------+---------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+--------+---------+------+-----+---------+-------+
| pnum | int(11) | YES | | NULL | |
| pprim | text | YES | | NULL | |
| phome | text | YES | | NULL | |
| pwork | text | YES | | NULL | |
| pother | text | YES | | NULL | |
+--------+---------+------+-----+---------+-------+
mysql> show columns from buyers_orders_with_phone;
+--------+------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+--------+------+------+-----+---------+-------+
| bid | text | YES | | NULL | |
| hphone | text | YES | | NULL | |
| wphone | text | YES | | NULL | |
| cphone | text | YES | | NULL | |
+--------+------+------+-----+---------+-------+
Explain
+----+-------------+-------+------+---------------+------+---------+------+-------+----------+----------------------------------------------+
| id | select_type | table | type | possible_keys | key | key_len | ref | rows | filtered | Extra |
+----+-------------+-------+------+---------------+------+---------+------+-------+----------+----------------------------------------------+
| 1 | SIMPLE | b | ALL | NULL | NULL | NULL | NULL | 8673 | 100.00 | Using where; Using temporary; Using filesort |
| 1 | SIMPLE | c | ALL | NULL | NULL | NULL | NULL | 75931 | 100.00 | Using where; Using join buffer |
+----+-------------+-------+------+---------------+------+---------+------+-------+----------+----------------------------------------------+
I realize that neither tables have a primary key, as these are only the columns that I need to search on and I extracted these columns from their original table. But using the original table it takes even longer because there is far more data to filter through.
I have other queries that are similar to this that will work with much more data so if I can make this one work in a reasonable time, I can get the others to work similarly.

Answer 1

A primary key is not a optimazation. What you need are non clustered index on your telephone text fields (one index per column). With these, you won't need to extract your data to seperate tables.

Answer 2

The legacy query is awful, sorry. It is full cartesian product.
The data structure cannot handle such queries effectively. You have 3 fields in one table and 4 in other and try to figure if any pair matches.
Possibly primary key and key for every phone column can improve this query, not sure, but it can make worse delete/insert/update performance.
Btw, you wrote that impossible to index by nullable column. It's not correct.
I can believe in only radical solution - change data structure or adding some kind of caching mechanism with trigger. But it is hard.