Update most documentation for NoteDb

Remove outdated references to ReviewDb. Where ambiguous terms like
"database" are used, make sure they are still technically accurate, or
else remove them.

After this change, all documentation should be up to date with respect
to the database backend, with the exception of note-db.txt itself.

Change-Id: I7134087dc56070788e81ada6ac504b3c8fe84c4c
diff --git a/Documentation/cmd-create-project.txt b/Documentation/cmd-create-project.txt
index 026d7b1..e48eea5 100644
--- a/Documentation/cmd-create-project.txt
+++ b/Documentation/cmd-create-project.txt
@@ -28,9 +28,8 @@
 == DESCRIPTION
 Creates a new bare Git repository under `gerrit.basePath`, using
 the project name supplied.  The newly created repository is empty
-(has no commits), but is registered in the Gerrit database so that
-the initial commit may be uploaded for review, or initial content
-can be pushed directly into a branch.
+(has no commits), and the initial content may either be uploaded for
+review, or pushed directly to a branch.
 
 If replication is enabled, this command also connects to each of
 the configured remote systems over SSH and uses command line git
diff --git a/Documentation/cmd-flush-caches.txt b/Documentation/cmd-flush-caches.txt
index 55d9083..5a84b9d 100644
--- a/Documentation/cmd-flush-caches.txt
+++ b/Documentation/cmd-flush-caches.txt
@@ -16,7 +16,7 @@
 truth when it needs the information again.
 
 Flushing a cache may be necessary if an administrator modifies
-database records directly in the database, rather than going through
+NoteDb metadata directly in a repository, rather than going through
 the Gerrit web interface.
 
 If no options are supplied, defaults to `--all`.
diff --git a/Documentation/cmd-index.txt b/Documentation/cmd-index.txt
index e999218..edb54b5 100644
--- a/Documentation/cmd-index.txt
+++ b/Documentation/cmd-index.txt
@@ -71,7 +71,7 @@
 	List projects visible to the caller.
 
 link:cmd-query.html[gerrit query]::
-	Query the change database.
+	Query the change search index.
 
 'gerrit receive-pack'::
 	'Deprecated alias for `git receive-pack`.'
diff --git a/Documentation/cmd-ls-user-refs.txt b/Documentation/cmd-ls-user-refs.txt
index cba7d1b..0363f60 100644
--- a/Documentation/cmd-ls-user-refs.txt
+++ b/Documentation/cmd-ls-user-refs.txt
@@ -32,8 +32,8 @@
 --user::
 -u::
 	Required; User for which the visible refs should be listed. Gerrit
-	will query the database to find matching users, so the
-	full identity/name does not need to be specified.
+	will query the index to find matching users, so the full
+	identity/name does not need to be specified.
 
 --only-refs-heads::
 	Only list the refs found under refs/heads/*
diff --git a/Documentation/cmd-query.txt b/Documentation/cmd-query.txt
index 79723c5..7eb24ea 100644
--- a/Documentation/cmd-query.txt
+++ b/Documentation/cmd-query.txt
@@ -1,7 +1,7 @@
 = gerrit query
 
 == NAME
-gerrit query - Query the change database
+gerrit query - Query the change search index
 
 == SYNOPSIS
 [verse]
@@ -24,7 +24,7 @@
 
 == DESCRIPTION
 
-Queries the change database and returns results describing changes
+Queries the change search index and returns results describing changes
 that match the input query.  More recently updated changes appear
 before older changes, which is the same order presented in the
 web interface.  For each matching change, the result contains data
diff --git a/Documentation/cmd-review.txt b/Documentation/cmd-review.txt
index 5417901..71385e2 100644
--- a/Documentation/cmd-review.txt
+++ b/Documentation/cmd-review.txt
@@ -27,7 +27,7 @@
 == DESCRIPTION
 Updates the current user's approval status of the specified patch
 sets and/or submits them for merging, sending out email
-notifications and updating the database.
+notifications and updating code review metadata.
 
 Patch sets may be specified in 'CHANGEID,PATCHSET' format, such as
 '8242,2', or 'COMMIT' format.
diff --git a/Documentation/config-gerrit.txt b/Documentation/config-gerrit.txt
index 94ee7ab..01db7ce 100644
--- a/Documentation/config-gerrit.txt
+++ b/Documentation/config-gerrit.txt
@@ -46,8 +46,8 @@
 link:pgm-MigrateAccountPatchReviewDb.html[MigrateAccountPatchReviewDb] program.
 Migration cannot be done while the server is running.
 +
-Also note that the db_name has to be a new db and not reusing gerrit's own review database,
-otherwise gerrit's init will remove the table.
+Also note that the db_name has to be a new db and not reusing an old ReviewDb
+database from a former 2.x site, otherwise gerrit's init will remove the table.
 
 ----
 [accountPatchReviewDb]
@@ -805,11 +805,10 @@
 +
 Cache entries contain important details of an active user, including
 their display name, preferences, and known email addresses. Entry
-information is obtained from the `accounts` database table.
+information is obtained from NoteDb data in the `All-Users` repo.
 
 +
-If direct updates are made to any of these database tables, this
-cache should be flushed.
+If direct updates are made to `All-Users`, this cache should be flushed.
 
 cache `"adv_bases"`::
 +
@@ -2623,8 +2622,7 @@
 +
 Maximum number of leaf terms to allow in a query. Too-large queries may
 perform poorly, so setting this option causes query parsing to fail fast
-before attempting to send them to the secondary index. Should this limit
-be reached, database is used instead of index as applicable.
+before attempting to send them to the secondary index.
 +
 When the index type is `LUCENE`, also sets the maximum number of clauses
 permitted per BooleanQuery. This is so that all enforced query limits
@@ -3318,9 +3316,9 @@
 [[note-db]]
 === Section noteDb
 
-NoteDb is the next generation of Gerrit storage backend, currently powering
-`googlesource.com`. For more information, including how to migrate your data,
-see the link:note-db.html[documentation].
+NoteDb is the Git-based database storage backend for Gerrit. For more
+information, including how to migrate data from an older Gerrit version, see the
+link:note-db.html[documentation].
 
 [[notedb.accounts.sequenceBatchSize]]notedb.accounts.sequenceBatchSize::
 +
diff --git a/Documentation/config-robot-comments.txt b/Documentation/config-robot-comments.txt
index cf5de10..0077697 100644
--- a/Documentation/config-robot-comments.txt
+++ b/Documentation/config-robot-comments.txt
@@ -36,7 +36,6 @@
 
 == Limitations
 
-* Robot comments are only supported with NoteDb, but not with ReviewDb.
 * Robot comments are not displayed in the web UI yet.
 * There is no support for draft robot comments, but robot comments are
   always published and visible to everyone who can see the change.
diff --git a/Documentation/dev-contributing.txt b/Documentation/dev-contributing.txt
index 6dce1e6..3b1c501 100644
--- a/Documentation/dev-contributing.txt
+++ b/Documentation/dev-contributing.txt
@@ -250,7 +250,6 @@
 Here are some design level objectives that you should keep in mind
 when coding:
 
-  * ORM entity objects should match exactly one row in the database.
   * Most client pages should perform only one RPC to load so as to
     keep latencies down.  Exceptions would apply to RPCs which need
     to load large data sets if splitting them out will help the
@@ -269,10 +268,11 @@
   * Don't leave repository objects (git or schema) open.  A .close()
     after every open should be placed in a finally{} block.
   * Don't leave UI components, which can cause new actions to occur,
-    enabled during RPCs which update the DB.  This is to prevent
-    people from submitting actions more than once when operating
-    on slow links.  If the action buttons are disabled, they cannot
-    be resubmitted and the user can see that Gerrit is still busy.
+    enabled during RPCs which update Git repositories, including NoteDb.
+    This is to prevent people from submitting actions more than once
+    when operating on slow links.  If the action buttons are disabled,
+    they cannot be resubmitted and the user can see that Gerrit is still
+    busy.
   * ...and so is Guava (previously known as Google Collections).
 
 
diff --git a/Documentation/dev-plugins.txt b/Documentation/dev-plugins.txt
index e84effd..f2bd273e 100644
--- a/Documentation/dev-plugins.txt
+++ b/Documentation/dev-plugins.txt
@@ -325,10 +325,10 @@
 
 Plugins' InitSteps are executed during the "Gerrit Plugin init" phase, after
 the extraction of the plugins embedded in the distribution .war file into
-`$GERRIT_SITE/plugins` and before the DB Schema initialization or upgrade.
+`$GERRIT_SITE/plugins` and before the site initialization or upgrade.
 
-A plugin's InitStep cannot refer to Gerrit's DB Schema or any other Gerrit
-runtime objects injected at startup.
+A plugin's InitStep cannot refer to any Gerrit runtime objects injected at
+startup.
 
 [source,java]
 ----
@@ -1573,9 +1573,8 @@
   // schedule a build
   [...]
   // update change
-  ReviewDb db = dbProvider.get();
   try (BatchUpdate bu = batchUpdateFactory.create(
-      db, project.getNameKey(), user, TimeUtil.nowTs())) {
+      project.getNameKey(), user, TimeUtil.nowTs())) {
     bu.addOp(change.getId(), new BatchUpdate.Op() {
       @Override
       public boolean updateChange(ChangeContext ctx) {
diff --git a/Documentation/install.txt b/Documentation/install.txt
index be55417..0885da1 100644
--- a/Documentation/install.txt
+++ b/Documentation/install.txt
@@ -61,8 +61,7 @@
 
 Gerrit stores configuration files, the server's SSH keys, and the
 managed Git repositories under a local directory, typically referred
-to as `'$site_path'`.  If the embedded H2 database is being used,
-its data files will also be stored under this directory.
+to as `'$site_path'`.
 
 You also have to decide where to store your server side git repositories. This
 can either be a relative path under `'$site_path'` or an absolute path
@@ -87,11 +86,10 @@
 then give ownership of that location to the `'gerrit'` user.
 
 If run from an interactive terminal, the init command will prompt through a
-series of configuration questions, including gathering information
-about the database created above.  If the terminal is not interactive,
-running the init command will choose some reasonable default selections,
-and will use the embedded H2 database. Once the init phase is complete,
-you can review your settings in the file `'$site_path/etc/gerrit.config'`.
+series of configuration questions.  If the terminal is not interactive,
+running the init command will choose some reasonable default selections.
+Once the init phase is complete, you can review your settings in the file
+`'$site_path/etc/gerrit.config'`.
 
 When running the init command, additional JARs might be downloaded to
 support optional selected functionality.  If a download fails a URL will
diff --git a/Documentation/metrics.txt b/Documentation/metrics.txt
index ced4609..6864c68 100644
--- a/Documentation/metrics.txt
+++ b/Documentation/metrics.txt
@@ -106,10 +106,6 @@
 * `sshd/sessions/created`: Rate of new SSH sessions.
 * `sshd/sessions/authentication_failures`: Rate of SSH authentication failures.
 
-=== SQL connections
-
-* `sql/connection_pool/connections`: SQL database connections.
-
 === Topics
 
 * `topic/cross_project_submit`: number of cross-project topic submissions.
diff --git a/Documentation/pgm-LocalUsernamesToLowerCase.txt b/Documentation/pgm-LocalUsernamesToLowerCase.txt
index 4b50961..53081a1 100644
--- a/Documentation/pgm-LocalUsernamesToLowerCase.txt
+++ b/Documentation/pgm-LocalUsernamesToLowerCase.txt
@@ -47,7 +47,7 @@
 
 == CONTEXT
 This command can only be run on a server which has direct
-connectivity to the metadata database.
+connectivity to the managed Git repositories.
 
 == EXAMPLES
 To convert the local username of every account to lower case:
diff --git a/Documentation/pgm-init.txt b/Documentation/pgm-init.txt
index 9a16cdf..f6c3c85 100644
--- a/Documentation/pgm-init.txt
+++ b/Documentation/pgm-init.txt
@@ -28,7 +28,7 @@
 into a newly created `$site_path`.
 
 If run in an existing `$site_path`, init upgrades existing resources
-(e.g. DB schema, plugins) as necessary.
+(e.g. NoteDb schema, plugins) as necessary.
 
 == OPTIONS
 -b::
@@ -100,8 +100,7 @@
 	folder.
 
 == CONTEXT
-This command can only be run on a server which has direct
-connectivity to the metadata database, and local access to the
+This command can only be run on a server which has direct local access to the
 managed Git repositories.
 
 GERRIT
diff --git a/Documentation/pgm-rulec.txt b/Documentation/pgm-rulec.txt
index 1b50812..2a987205 100644
--- a/Documentation/pgm-rulec.txt
+++ b/Documentation/pgm-rulec.txt
@@ -33,8 +33,7 @@
 	Compile rules for the specified project.
 
 == CONTEXT
-This command can only be run on a server which has direct
-connectivity to the metadata database, and local access to the
+This command can only be run on a server which has local access to the
 managed Git repositories.
 
 Caching needs to be enabled. See
diff --git a/Documentation/user-upload.txt b/Documentation/user-upload.txt
index 751e886..56602e2 100644
--- a/Documentation/user-upload.txt
+++ b/Documentation/user-upload.txt
@@ -732,7 +732,7 @@
 Gerrit to provide magical refs, such as `+refs/for/*+` for new
 change submission and `+refs/changes/*+` for change replacement.
 When a push request is received to create a ref in one of these
-namespaces Gerrit performs its own logic to update the database,
+namespaces Gerrit performs its own logic to update the review metadata,
 and then lies to the client about the result of the operation.
 A successful result causes the client to believe that Gerrit has
 created the ref, but in reality Gerrit hasn't created the ref at all.