query: Add Contains operator

[metalmatze]

Adding a |= operator to FrostDB.
It's basically LIKE '%$foo%' in SQL. It'll return true whenever the string contains the substring.

[thorfour]

Do we need this if we could do this with regexp matching?

[metalmatze]

Interesting idea to use the regexp.
We still need this as it uses substring matching rather than full regexp which I assume to be a lot cheaper. We could benchmark this.

[thorfour]

Interesting idea to use the regexp. We still need this as it uses substring matching rather than full regexp which I assume to be a lot cheaper. We could benchmark this.

Instead of regexp matching instead have the regexp operator downgrade itself into a Contains matcher if it detects it's regexp is a substring matcher.

[metalmatze]

I'll start fresh from the regexp angle.

[brancz]

What Thor said would be a great logical optimizer.