Docs: notes on DBM library changeovers

diff --git a/doc/doc-docbook/spec.xfpt b/doc/doc-docbook/spec.xfpt
index 9a52502d25a63dbde91e308424835722590dc5bc..8d61543cdff8be0b6ff22e397af0aab0bac1b730 100644 (file)
--- a/doc/doc-docbook/spec.xfpt
+++ b/doc/doc-docbook/spec.xfpt
@@ -1764,6 +1764,12 @@ distributors have chosen to bundle different libraries with their packaged
 versions. However, the more recent releases seem to have standardized on the
 Berkeley DB library.
 
+.new
+Ownership of the Berkeley DB library has moved to a major corporation;
+development seems to have stalled and documentation is not freely available.
+This is probably not tenable for the long term use by Exim.
+.wen
+
 Different DBM libraries have different conventions for naming the files they
 use. When a program opens a file called &_dbmfile_&, there are several
 possibilities:
@@ -1852,6 +1858,17 @@ DBMLIB=/usr/local/lib/db-4.1/libdb.a
 There is further detailed discussion about the various DBM libraries in the
 file &_doc/dbm.discuss.txt_& in the Exim distribution.
 
+.new
+When moving from one DBM library to another,
+for the hints databases it suffices to just remove all the files in the
+directory named &"db/"& under the spool directory.
+This is because hints are only for optimisation and will be rebuilt
+during normal operations.
+Non-hints DBM databases (used by &"dbm"& lookups in the configuration)
+will need individual rebuilds for the new DBM library.
+This is not done automatically
+.wen
+
 
 
 .section "Pre-building configuration" "SECID25"

diff --git a/doc/doc-txt/dbm.discuss.txt b/doc/doc-txt/dbm.discuss.txt
index 50f0687137bb15e187c916de0c075e4b6e8a3cee..4f3622d690b694261ea574f1d2278fb7a8fd38cf 100644 (file)
--- a/doc/doc-txt/dbm.discuss.txt
+++ b/doc/doc-txt/dbm.discuss.txt
@@ -153,6 +153,7 @@ Berkeley DB 1.8x
 1.85 was the most widespread DB 1.x release; there is also a 1.86 bug-fix
 release, but the belief is that the bugs it fixes will not affect Exim.
 However, maintenance for 1.x releases has been phased out.
+Exim no loger supports these releases for current builds.
 
 This dbm library can be called by Exim in one of two ways: via the ndbm
 compatibility interface, or via its own native interface. There are two
@@ -206,6 +207,8 @@ the file name handed to it.
 DB 2.x does not do any automatic locking of its own; it does have a set of
 functions for various forms of locking, but Exim does not use them.
 
+Exim no longer supports these releases for current builds.
+
 
 Berkeley DB 3.x
 ---------------
@@ -227,6 +230,20 @@ Berkeley DB 4.x
 The 4.x series is a development of the 2.x and 3.x series, and the above
 comments apply.
 
+Berkeley DB 5.x
+---------------
+
+The 5.x versions seem to be current in several Linux disributions
+as of writing (2024). Exim uses them under the assumption that the
+API is the same as the version 4.1 library.
+
+Berkeley DB 6+
+---------------
+
+These versions exist, but documentation does not seem to be available.
+Exim does not support them.
+
+
 
 tdb
 ---
@@ -319,3 +336,5 @@ exists, just in case. Proceed as follows:
 
 Philip Hazel
 Last update: June 2002
+
+(+undates July 2024, jgh)