update documentation

docs/lnd/postgres.md

@@ -0,0 +1,31 @@
+# Postgres support in LND
+
+With the introduction of the `kvdb` interface, LND can support multiple database
+backends. One of the supported backends is Postgres. This document
+describes how it can be configured.
+
+## Building LND with postgres support
+
+To build LND with postgres support, include the following build tag:
+
+```shell
+⛰  make tags="kvdb_postgres"
+```
+
+## Configuring Postgres for LND
+
+In order for LND to run on Postgres, an empty database should already exist. A
+database can be created via the usual ways (psql, pgadmin, etc). A user with
+access to this database is also required.
+
+Creation of a schema and the tables is handled by LND automatically.
+
+## Configuring LND for Postgres
+
+LND is configured for Postgres through the following configuration options:
+
+* `db.backend=postgres` to select the Postgres backend.
+* `db.postgres.dsn=...` to set the database connection string that includes
+  database, user and password.
+* `db.postgres.timeout=...` to set the connection timeout. If not set, no
+  timeout applies.

docs/lnd/release-notes/release-notes-0.14.0.md

@@ -38,6 +38,27 @@ instantaneous. Read the [guide on leader
 election](https://github.com/lightningnetwork/lnd/blob/master/docs/leader_election.md)
 for more information.
 
+### Postgres database support
+
+This release adds [support for Postgres as a database
+backend](https://github.com/lightningnetwork/lnd/pull/5366) to lnd. Postgres
+has several advantages over the default bbolt backend:
+* Better handling of large data sets.
+* On-the-fly database compaction (auto vacuum).
+* Database replication.
+* Inspect data while lnd is running (bbolt opens the database exclusively).
+* Usage of industry-standard tools to manage the stored data, get performance
+  metrics, etc.
+
+Furthermore, the SQL platform opens up possibilities to improve lnd's
+performance in the future. Bbolt's single-writer model is a severe performance
+bottleneck, whereas Postgres offers a variety of locking models. Additionally,
+structured tables reduce the need for custom serialization/deserialization code
+in `lnd`, saving developer time and limiting the potential for bugs.
+
+Instructions for enabling Postgres can be found in
+[docs/postgres.md](../postgres.md).
+
 ## Protocol Extensions
 
 ### Explicit Channel Negotiation
@@ -79,6 +100,12 @@ proposed channel type is used.
 
 * [Adds an option to the BakeMacaroon rpc "allow-external-permissions,"](https://github.com/lightningnetwork/lnd/pull/5304) which makes it possible to bake a macaroon with external permissions. That way, the baked macaroons can be used for services beyond LND. Also adds a new CheckMacaroonPermissions rpc that checks that the macaroon permissions and other restrictions are being followed. It can also check permissions not native to LND.
 
+* [A new RPC middleware
+  interceptor](https://github.com/lightningnetwork/lnd/pull/5101) was added that
+  allows external tools to hook into `lnd`'s RPC server and intercept any
+  requests made with custom macaroons (and also the responses to those
+  requests).
+
 ### Batched channel funding
 
 [Multiple channels can now be opened in a single
@@ -131,6 +158,8 @@ you.
 * Locally force closed channels are now [kept in the channel.backup file until
   their time lock has fully matured](https://github.com/lightningnetwork/lnd/pull/5528).
 
+* [Cooperative closes optimistically shutdown the associated `link` before closing the channel.](https://github.com/lightningnetwork/lnd/pull/5618)
+
 ## Build System
 
 * [A new pre-submit check has been