Berkeley DB (libdb)

This repository is two things at once:

1. A historical archive of Berkeley DB — the complete published lineage of
   releases and official patches that could be recovered, preserved as tags and
   GitHub Releases for reference and git diff-able history.
2. A living fork under active development on the master branch, where
   new work (bug fixes, portability, performance, and new features) happens.

Berkeley DB is an embedded, transactional key/value storage engine (B-tree,
Hash, Queue, Recno) with ACID transactions, fine-grained locking, write-ahead
logging, MVCC snapshot isolation, and replication. It is a library you link into
your application — no server process.

Branches and tags

Ref	What it is
master	The living fork. Active development; the place to base PRs.
historical	A linear, chronological reconstruction of Berkeley DB 1.85 (1992) → 5.1.29 (2011). Archival; never rebased.
vX.Y.Z tags	Each upstream release, imported verbatim (with its upstream .tar.gz attached to the GitHub Release).
vX.Y.Z.N tags	Each official upstream patch, applied as its own commit.
vX.Y.Z-NC tags	"No-Crypto" export variants, branched from their base release.
v4.6.21-SSI	Michael Cahill's SIGMOD-2008 Serializable Snapshot Isolation research prototype, reproduced verbatim on 4.6.21.
v5.3.21/28, v5.3.29	The maintained 5.3.x line that master builds on.

Browsing the archive

shCopy
git tag -l | sort -V                 # every archived version
git log --oneline --reverse historical
git diff v4.5.20 v4.6.21             # what changed between releases
git diff v4.6.21 v4.6.21.2           # what a single official patch changed
git diff v4.2.52 v4.2.52-NC          # what the no-crypto variant strips

See the historical branch README
for full provenance and the per-version index.

What's new on the living fork

• Serializable Snapshot Isolation (SSI) — an opt-in DB_TXN_SNAPSHOT_SAFE
  transaction mode that prevents snapshot-isolation anomalies (e.g. write-skew)
  by detecting dangerous read/write dependency structures and aborting the
  pivot with DB_SNAPSHOT_CONFLICT. This is the first of the planned features
  in ROADMAP.md, which targets matching or beating InnoDB and
  WiredTiger on multicore/NUMA scalability and performance.

Building

shCopy
cd build_unix
../dist/configure            # see ../dist/configure --help for options
make -j

# Common variants:
#   --enable-debug --enable-diagnostic   developer build with assertions
#   --enable-cxx                          C++ API
#   --enable-sql                          SQL (SQLite-compatible) API
#   --enable-test --with-tcl=<dir>        build the TCL test harness

To view the original distribution and API documentation, open
docs/index.html in a browser.

Testing

shCopy
cd build_unix
../dist/configure --enable-debug --enable-test --with-tcl=/usr/lib/tcl8.6 && make -j
tclsh
  % source ../test/tcl/test.tcl
  % ssi001        ;# SSI write-skew test
  % run_std       ;# the standard suite (long)

Contributing

See .github/CONTRIBUTING.md. PRs target master,
are built across the CI matrix (Linux/macOS/Windows,
multiple compilers and configure options), and are reviewed by maintainers and
the automated OCR reviewer.

License

Berkeley DB is distributed under its original license; see
LICENSE. Individual archived versions carry the license in effect
for that release.