Support various index types in index Macros

[jordan8037310]

Opening a ticket as I might work on this:

• PgSQL supports a range of index types: B-tree, Hash, GiST, SP-GiST, GIN and BRIN
• It might be worthwhile to expand the macro to include a type variable with the default being B-Tree / unset. A case statement could implement one of the index types inside of the macro based on the type.

My use case is applying a GIN index on some JSON data I'm storing, which I believe will speed up some of my dbt transformations downstream.

[sgoley]

@jordan8037310 all for it.
Was just exposed to the trigram index type myself late last week so I would have my own contributions to make sure that option is covered.

More info:
https://www.postgresql.org/docs/9.6/pgtrgm.html

[sgoley]

@jordan8037310 finally got this into the develop branch! see: #10

Sorry for the delay, had been pretty busy the last couple months but trying to find some time to starting working on this again.

[jordan8037310]

Great! I myself haven't been spending much time in our Pg dbt project either, but that could change shortly

[sgoley]

@jordan8037310 sounds great! Do you have examples of the json that I could use for testing and how you apply the GIN index? I can work that into my testing since I'm not too familiar with it.