update README

README.md

@@ -1,39 +1,51 @@
 # pg_quack
 
-pg_quack is PostgreSQL with Embedded DuckDB :duck:
+quack is a PostgreSQL extension that embeds DuckDB into Postgres. :duck:
 
-## Installation
+Once loaded, DuckDB is used for all read queries unless disabled. In the future, more options will be available.
+
+## Status
 
-### With pgxman
+This project is pre-alpha. It is not currently suitable for production.
 
-1. [Install pgxman](https://pgxman.com/)
-1. `pgxman install pg_quack`
+## Roadmap
 
-### From source
+This is a high-level roadmap, subject to change. In the near future, we will provide a more detailed roadmap
+via a Github Project.
 
-1. `make install`
-1. (Optional) Create quack directory and set permissions so PostgreSQL process can write to it.
-   Directory can be changed with `quack.data_dir` configuration parameter. By default, the
-   directory is `quack` in your Postgres data directory.
+* [ ] Allow DuckDB to read from heap tables. This gives a stable reference implementation and stable
+      testing for query execution, as well as the capability to read from heap tables for joins.
+* [ ] Implement a pluggable storage API to allow DuckDB to read from a variety of Postgres
+      (or even non-Postgres) storage methods. This API will allow implementors to bypass Postgres
+      to connect data directly to DuckDB.
+* [ ] Allow quack to read from any implemented Postgres table access method.
+* [ ] Implement a columnar datastore that supports concurrent access, is MVCC-capable and ACID-compliant,
+      and can be backed by cloud storage. Connect this datastore to DuckDB for reads and Postgres
+      for writes.
+* [ ] Build a cloud storage backend for the columnar datastore that provides "bottomless"
+      storage with a local cache.
+* [ ] Be able to intelligently execute queries via DuckDB or Postgres based on query plan or other
+      factors.
+
+## Installation
 
 ```
-postgres=# show quack.data_dir ;
-           quack.data_dir
-------------------------------------
- /opt/database/postgres/data/quack/
-(1 row)
+make install
 ```
 
+Prerequisites:
+
+* Postgres 16
+* Ubuntu 22.04 or MacOS
+* Standard set of build tools for building Postgres extensions
+* [Build tools that are required to build DuckDB](https://duckdb.org/docs/dev/building/build_instructions)
+
 ## Usage
 
+Currently the extension is enabled anytime it is loaded:
+
 ```
-CREATE TABLE quack_test (...) USING quack;
+LOAD quack;
 ```
 
-## Limitations
-
-* PG 14 and PG 15 only (PG 16 is not yet supported)
-* Only COPY, INSERT, and SELECT are supported.
-* Only single connection can execute INSERT and SELECT against quack table
-* Limited support for only basic data types
-* You cannot query between `quack` tables and other storage methods (including Postgres `heap` tables).
+Then query as usual.